diff --git a/collects/2htdp/batch-io.rkt b/collects/2htdp/batch-io.rkt
index b4af560368..c44a1ff5ca 100644
--- a/collects/2htdp/batch-io.rkt
+++ b/collects/2htdp/batch-io.rkt
@@ -1,12 +1,12 @@
 #lang scheme
 
-(require (for-syntax syntax/parse) 
-         srfi/13 htdp/error 
+(require (for-syntax syntax/parse)
+         srfi/13 htdp/error
          (rename-in lang/prim (first-order->higher-order f2h))
-         "private/csv/csv.ss")
+         "private/csv/csv.rkt")
 
 ;; todo?
-;; -- export tokenization? 
+;; -- export tokenization?
 
 ;; -----------------------------------------------------------------------------
 (provide simulate-file) ;; syntax (simulate-file reader string ...)
diff --git a/collects/2htdp/image.rkt b/collects/2htdp/image.rkt
index 6f25be17a4..3df69cebd0 100644
--- a/collects/2htdp/image.rkt
+++ b/collects/2htdp/image.rkt
@@ -33,9 +33,9 @@ and they all have good sample contracts. (It is amazing what we can do with kids
 |#
 
 
-(require (except-in "../mrlib/image-core.ss" make-color color make-pen pen)
-         "private/image-more.ss"
-         "private/img-err.ss"
+(require (except-in "../mrlib/image-core.rkt" make-color color make-pen pen)
+         "private/image-more.rkt"
+         "private/img-err.rkt"
          (only-in lang/prim provide-primitive provide-primitives define-primitive)
          htdp/error)
 
diff --git a/collects/2htdp/private/image-more.rkt b/collects/2htdp/private/image-more.rkt
index 0599350f57..4e7fb86648 100644
--- a/collects/2htdp/private/image-more.rkt
+++ b/collects/2htdp/private/image-more.rkt
@@ -1,7 +1,7 @@
 #lang racket/base
 
 (require mrlib/image-core
-         "img-err.ss"
+         "img-err.rkt"
          racket/match
          racket/contract
          racket/class
diff --git a/collects/2htdp/private/last.rkt b/collects/2htdp/private/last.rkt
index e315007076..b7dbf1af5e 100644
--- a/collects/2htdp/private/last.rkt
+++ b/collects/2htdp/private/last.rkt
@@ -1,6 +1,6 @@
 #lang scheme/gui
 
-(require "timer.ss")
+(require "timer.rkt")
 
 (provide last-mixin)
 
diff --git a/collects/2htdp/private/timer.rkt b/collects/2htdp/private/timer.rkt
index 830cd04830..459b242222 100644
--- a/collects/2htdp/private/timer.rkt
+++ b/collects/2htdp/private/timer.rkt
@@ -8,7 +8,7 @@
 ;; tick field, which the super-class uses to define the callback.
 
 
-(require "check-aux.ss")
+(require "check-aux.rkt")
 
 (provide clock-mixin start-stop<%>)
 
diff --git a/collects/2htdp/private/universe.rkt b/collects/2htdp/private/universe.rkt
index f4eca8f378..691a15fd96 100644
--- a/collects/2htdp/private/universe.rkt
+++ b/collects/2htdp/private/universe.rkt
@@ -1,10 +1,10 @@
 #lang racket/gui
 
-(require (for-syntax "syn-aux.ss")
-         "checked-cell.ss"
-         "check-aux.ss"
-         "timer.ss"    
-         "last.ss"
+(require (for-syntax "syn-aux.rkt")
+         "checked-cell.rkt"
+         "check-aux.rkt"
+         "timer.rkt"
+         "last.rkt"
          htdp/error
          (only-in mzlib/etc evcase)
          string-constants)
diff --git a/collects/2htdp/private/world.rkt b/collects/2htdp/private/world.rkt
index 65dd60a6aa..24046f2d06 100644
--- a/collects/2htdp/private/world.rkt
+++ b/collects/2htdp/private/world.rkt
@@ -1,11 +1,11 @@
 #lang scheme/gui
 
-(require "check-aux.ss"
-         "timer.ss"
-         "last.ss"
-         "checked-cell.ss"
-         "stop.ss"
-         "universe-image.ss"
+(require "check-aux.rkt"
+         "timer.rkt"
+         "last.rkt"
+         "checked-cell.rkt"
+         "stop.rkt"
+         "universe-image.rkt"
          htdp/error
          mzlib/runtime-path
          mrlib/bitmap-label
diff --git a/collects/2htdp/tests/profile-robby.rkt b/collects/2htdp/tests/profile-robby.rkt
index ce1da9d02c..cd16989275 100644
--- a/collects/2htdp/tests/profile-robby.rkt
+++ b/collects/2htdp/tests/profile-robby.rkt
@@ -2,7 +2,7 @@
 (require profile
          scheme/runtime-path)
 
-(define-runtime-path perform-robby "perform-robby.ss")
+(define-runtime-path perform-robby "perform-robby.rkt")
 
 (profile-thunk
  (λ ()
diff --git a/collects/2htdp/tests/test-image.rkt b/collects/2htdp/tests/test-image.rkt
index b4d4a61dba..2fb0eda246 100644
--- a/collects/2htdp/tests/test-image.rkt
+++ b/collects/2htdp/tests/test-image.rkt
@@ -2275,10 +2275,10 @@
          [normalized (normalize-shape (image-shape img))]
          [norm-size (image-struct-count normalized)]) 
     (unless (normalized-shape? normalized)
-      (error 'test-image.ss "found a non-normalized shape after normalization:\n~s" 
+      (error 'test-image.rkt "found a non-normalized shape after normalization:\n~s" 
              img-sexp))
     (unless (equal? norm-size raw-size)
-      (error 'test-image.ss "found differing sizes for ~s:\n  ~s\n  ~s" 
+      (error 'test-image.rkt "found differing sizes for ~s:\n  ~s\n  ~s" 
              img-sexp raw-size norm-size))))
 
 (time
diff --git a/collects/2htdp/uchat/chatter.rkt b/collects/2htdp/uchat/chatter.rkt
index 07019d966e..bfefc0a6a2 100644
--- a/collects/2htdp/uchat/chatter.rkt
+++ b/collects/2htdp/uchat/chatter.rkt
@@ -3,7 +3,7 @@
 #reader(lib "htdp-intermediate-lambda-reader.ss" "lang")((modname chatter) (read-case-sensitive #t) (teachpacks ()) (htdp-settings #(#t constructor repeating-decimal #f #t none #f ())))
 (require 2htdp/universe)
 (require htdp/image)
-(require "auxiliaries.ss")
+(require "auxiliaries.rkt")
 
 #|
 
diff --git a/collects/2htdp/universe.rkt b/collects/2htdp/universe.rkt
index 80ec05b9d5..2ead67ef91 100644
--- a/collects/2htdp/universe.rkt
+++ b/collects/2htdp/universe.rkt
@@ -12,16 +12,16 @@
    -- make window resizable :: why
 |#
 
-(require (for-syntax "private/syn-aux.ss"
+(require (for-syntax "private/syn-aux.rkt"
                      stepper/private/shared)
-         "private/syn-aux-aux.ss" 
-         "private/syn-aux.ss"
-         "private/check-aux.ss"
-         "private/universe-image.ss"
-         "private/world.ss"
-         "private/universe.ss"
-         "private/launch-many-worlds.ss"
-         "private/stop.ss"
+         "private/syn-aux-aux.rkt"
+         "private/syn-aux.rkt"
+         "private/check-aux.rkt"
+         "private/universe-image.rkt"
+         "private/world.rkt"
+         "private/universe.rkt"
+         "private/launch-many-worlds.rkt"
+         "private/stop.rkt"
          htdp/error
          (rename-in lang/prim (first-order->higher-order f2h)))
 
diff --git a/collects/2htdp/utest/sam.rkt b/collects/2htdp/utest/sam.rkt
index db883bb19d..01e83d56ae 100644
--- a/collects/2htdp/utest/sam.rkt
+++ b/collects/2htdp/utest/sam.rkt
@@ -1,7 +1,7 @@
 ;; The first three lines of this file were inserted by DrScheme. They record metadata
 ;; about the language level of this file in a form that our tools can easily process.
 #reader(lib "htdp-intermediate-lambda-reader.ss" "lang")((modname sam) (read-case-sensitive #t) (teachpacks ()) (htdp-settings #(#t constructor repeating-decimal #f #t none #f ())))
-(require "shared.ss")
-(require 2htdp/universe)
+(require "shared.rkt"
+         2htdp/universe)
 
 (launch-many-worlds (make-player 200 "sam") (make-player 100 "carl"))
diff --git a/collects/2htdp/utest/shared.rkt b/collects/2htdp/utest/shared.rkt
index 931022e972..4d304b19a2 100644
--- a/collects/2htdp/utest/shared.rkt
+++ b/collects/2htdp/utest/shared.rkt
@@ -1,7 +1,7 @@
 #lang scheme
 
 (require 2htdp/universe htdp/testing htdp/image)
-;(require "../2htdp/universe.ss" htdp/testing)
+;(require "../universe.rkt" htdp/testing)
 
 ;; World   = Number | 'resting 
 (define WORLD0 'resting)
diff --git a/collects/algol60/algol60.rkt b/collects/algol60/algol60.rkt
index 4c50fca329..c6b7eb573d 100644
--- a/collects/algol60/algol60.rkt
+++ b/collects/algol60/algol60.rkt
@@ -1,15 +1,15 @@
 #cs(module algol60 mzscheme
-     (require-for-syntax "parse.ss" 
-			 ;; Parses to generate an AST. Identifiers in the AST
-			 ;; are represented as syntax objects with source location.
-			 
-                         "simplify.ss"
-			 ;; Desugars the AST, transforming `for' to `if'+`goto',
-			 ;; and flattening `if' statements so they are always
-			 ;; of the for `if <exp> then goto <label> else goto <label>'
+     (require-for-syntax "parse.rkt"
+                         ;; Parses to generate an AST. Identifiers in the AST
+                         ;; are represented as syntax objects with source location.
 
-                         "compile.ss"
-			 ;; Compiles a simplified AST to Scheme.
+                         "simplify.rkt"
+                         ;; Desugars the AST, transforming `for' to `if'+`goto',
+                         ;; and flattening `if' statements so they are always
+                         ;; of the for `if <exp> then goto <label> else goto <label>'
+
+                         "compile.rkt"
+                         ;; Compiles a simplified AST to Scheme.
 
                          mzlib/file)
 
@@ -17,11 +17,11 @@
      ;; introduced by compilation, the identifiers can
      ;; refer to runtime functions and primitives, as
      ;; well as mzscheme:
-     (require "runtime.ss" "prims.ss")
-              
-     
+     (require "runtime.rkt" "prims.rkt")
+
+
      (provide include-algol)
-     
+
      (define-syntax (include-algol stx)
        (syntax-case stx ()
          [(_ str)
diff --git a/collects/algol60/base.rkt b/collects/algol60/base.rkt
index 7f831609bd..a994ca1be7 100644
--- a/collects/algol60/base.rkt
+++ b/collects/algol60/base.rkt
@@ -1,10 +1,10 @@
 (module base mzscheme
-  (require "prims.ss"
-	   "runtime.ss")
+  (require "prims.rkt"
+           "runtime.rkt")
 
   (define base-importing-stx #'here)
 
   (provide (all-from mzscheme)
-	   (all-from "prims.ss")
-           (all-from "runtime.ss")
+           (all-from "prims.rkt")
+           (all-from "runtime.rkt")
            base-importing-stx))
diff --git a/collects/algol60/compile.rkt b/collects/algol60/compile.rkt
index d7aaa3256a..5c2429c148 100644
--- a/collects/algol60/compile.rkt
+++ b/collects/algol60/compile.rkt
@@ -1,12 +1,12 @@
 #cs(module compile mzscheme
-     (require "parse.ss"
+     (require "parse.rkt"
               mzlib/match
               mzlib/list)
-     
+
      (provide compile-simplified)
 
-     ;; The compiler generates references to prim.ss and
-     ;; runtime.ss exports, as well as Racket forms
+     ;; The compiler generates references to "prims.rkt" and
+     ;; "runtime.rkt" exports, as well as Racket forms
      ;; and functions. The `ctx' argument provides
      ;; an appropriate context for those bindings (in
      ;; the form of a syntax object to use with d->s-o).
diff --git a/collects/algol60/info.rkt b/collects/algol60/info.rkt
index 28f9c3579b..5ab3f358d6 100644
--- a/collects/algol60/info.rkt
+++ b/collects/algol60/info.rkt
@@ -1,5 +1,5 @@
 #lang setup/infotab
 
-(define tools '(("tool.ss")))
+(define tools '(("tool.rkt")))
 (define tool-names '("Algol 60"))
 (define scribblings '(("algol60.scrbl" () (experimental 40))))
diff --git a/collects/algol60/parse.rkt b/collects/algol60/parse.rkt
index 81340752e3..e41ae2e39a 100644
--- a/collects/algol60/parse.rkt
+++ b/collects/algol60/parse.rkt
@@ -1,11 +1,11 @@
 #cs(module parse mzscheme
      (require parser-tools/lex
               (prefix : parser-tools/lex-sre)
-              "cfg-parser.ss"
-	      parser-tools/yacc
+              "cfg-parser.rkt"
+              parser-tools/yacc
               syntax/readerr
-              "prims.ss")
-     
+              "prims.rkt")
+
      (define-lex-abbrevs [lex:letter (:or (:/ #\a #\z) (:/ #\A #\Z))]
                          [lex:digit (:/ #\0 #\9)]
                          [lex:whitespace (:or #\newline #\return #\tab #\space #\vtab)]
diff --git a/collects/algol60/simplify.rkt b/collects/algol60/simplify.rkt
index 78b65a07a5..098f0afea5 100644
--- a/collects/algol60/simplify.rkt
+++ b/collects/algol60/simplify.rkt
@@ -1,10 +1,10 @@
 #cs(module simplify mzscheme
-     (require "parse.ss"
-              "prims.ss"
+     (require "parse.rkt"
+              "prims.rkt"
               mzlib/match)
-     
+
      (provide simplify)
-      
+
      ;; flatten/label-block : list-of-decl list-of-stmt -> block-stmt
      ;; Desugars `for', converts `if' so that it's always of the form
      ;; `if <test> then goto <label> else goto <label>', flattens
diff --git a/collects/algol60/tool.rkt b/collects/algol60/tool.rkt
index 67154c4198..e661b017f5 100644
--- a/collects/algol60/tool.rkt
+++ b/collects/algol60/tool.rkt
@@ -3,13 +3,13 @@
            mred
            mzlib/unit
            mzlib/class
-           "parse.ss"
-           "simplify.ss"
-           "compile.ss"
-	   compiler/embed
-	   string-constants
-	   errortrace/errortrace-lib
-           (prefix bd: "bd-tool.ss"))
+           "parse.rkt"
+           "simplify.rkt"
+           "compile.rkt"
+           compiler/embed
+           string-constants
+           errortrace/errortrace-lib
+           (prefix bd: "bd-tool.rkt"))
 
   (provide tool@)
 
@@ -44,7 +44,7 @@
 	      (define/override (get-mrflow-primitives-filename)
 		(build-path (collection-path "mrflow")
 			    "primitives"
-			    "algol60.ss"))
+			    "algol60.rkt"))
 	      (super-instantiate ()))
 	    %))
 
diff --git a/collects/browser/browser-sig.rkt b/collects/browser/browser-sig.rkt
index 6193f3d86e..f34f09d7c9 100644
--- a/collects/browser/browser-sig.rkt
+++ b/collects/browser/browser-sig.rkt
@@ -1,6 +1,6 @@
 (module browser-sig mzscheme
   (require mzlib/unit
-           "private/sig.ss")
+           "private/sig.rkt")
 
   (provide browser^)
   
@@ -8,4 +8,3 @@
     ((open hyper^)
      (open html-export^)
      (open bullet-export^))))
-
diff --git a/collects/browser/browser-unit.rkt b/collects/browser/browser-unit.rkt
index 58ed88adb4..efc05dd3fe 100644
--- a/collects/browser/browser-unit.rkt
+++ b/collects/browser/browser-unit.rkt
@@ -5,11 +5,11 @@
            net/tcp-sig
            net/url-sig
            net/url-unit
-           "browser-sig.ss"
-           "private/sig.ss"
-           "private/bullet.ss"
-           "private/html.ss"
-           "private/hyper.ss")
+           "browser-sig.rkt"
+           "private/sig.rkt"
+           "private/bullet.rkt"
+           "private/html.rkt"
+           "private/hyper.rkt")
   
   (provide browser@)
   
diff --git a/collects/browser/browser.rkt b/collects/browser/browser.rkt
index 33cd0a4b74..e587a0d269 100644
--- a/collects/browser/browser.rkt
+++ b/collects/browser/browser.rkt
@@ -7,8 +7,8 @@
            net/tcp-sig
            net/url-sig
            net/url
-           "browser-sig.ss"
-           "browser-unit.ss")
+           "browser-sig.rkt"
+           "browser-unit.rkt")
   
   (provide-signature-elements browser^)
   
diff --git a/collects/browser/bullet-snip.rkt b/collects/browser/bullet-snip.rkt
index 3d0f0c85ba..b603e8c23d 100644
--- a/collects/browser/bullet-snip.rkt
+++ b/collects/browser/bullet-snip.rkt
@@ -1,3 +1,3 @@
 (module bullet-snip mzscheme
-  (require "private/bullet.ss")
+  (require "private/bullet.rkt")
   (provide (rename bullet-snip-class snip-class)))
diff --git a/collects/browser/htmltext.rkt b/collects/browser/htmltext.rkt
index 74f1512a97..55c23ebf98 100644
--- a/collects/browser/htmltext.rkt
+++ b/collects/browser/htmltext.rkt
@@ -2,12 +2,12 @@
 (module htmltext mzscheme
   (require mzlib/unit
            mzlib/class
-           "browser-sig.ss"
-           "private/sig.ss"
-           "private/html.ss"
-           "private/bullet.ss"
-	   net/url
-	   net/url-sig
+           "browser-sig.rkt"
+           "private/sig.rkt"
+           "private/html.rkt"
+           "private/bullet.rkt"
+           net/url
+           net/url-sig
            mred
            mred/mred-unit
            mred/mred-sig
diff --git a/collects/browser/info.rkt b/collects/browser/info.rkt
index 71fda80ce0..bbeb1dc85f 100644
--- a/collects/browser/info.rkt
+++ b/collects/browser/info.rkt
@@ -1,5 +1,5 @@
 #lang setup/infotab
 
-(define tools (list (list "tool.ss")))
+(define tools (list (list "tool.rkt")))
 (define tool-names (list "Browser"))
 (define scribblings '(("browser.scrbl" () (gui-library))))
diff --git a/collects/browser/main.rkt b/collects/browser/main.rkt
index 521ee94e32..b5d855492c 100644
--- a/collects/browser/main.rkt
+++ b/collects/browser/main.rkt
@@ -1,3 +1,3 @@
 #lang scheme/base
-(require "browser.ss")
-(provide (all-from-out "browser.ss"))
+(require "browser.rkt")
+(provide (all-from-out "browser.rkt"))
diff --git a/collects/browser/private/btree.rkt b/collects/browser/private/btree.rkt
index af6c8cb0be..daa4616447 100644
--- a/collects/browser/private/btree.rkt
+++ b/collects/browser/private/btree.rkt
@@ -1,6 +1,6 @@
 #lang scheme/unit
 
-(require "sig.ss")
+(require "sig.rkt")
 
 ;; Implements a red-black tree with relative indexing along right
 ;; splines. This allows the usual O(log(n)) operations, plus a
diff --git a/collects/browser/private/html.rkt b/collects/browser/private/html.rkt
index e6dd126ab1..b897eca2b0 100644
--- a/collects/browser/private/html.rkt
+++ b/collects/browser/private/html.rkt
@@ -1,6 +1,6 @@
 #lang scheme/unit
 
-(require "sig.ss"
+(require "sig.rkt"
          mred/mred-sig
          scheme/file
          mzlib/port
@@ -8,9 +8,9 @@
          (only-in html read-html-as-xml read-html-comments use-html-spec)
          (except-in xml read-comments)
          mzlib/class
-         "bullet.ss"
-         "option-snip.ss"
-         "entity-names.ss")
+         "bullet.rkt"
+         "option-snip.rkt"
+         "entity-names.rkt")
 
 
 (import mred^ url^)
diff --git a/collects/browser/private/hyper.rkt b/collects/browser/private/hyper.rkt
index 83f967f038..5471ba317e 100644
--- a/collects/browser/private/hyper.rkt
+++ b/collects/browser/private/hyper.rkt
@@ -28,7 +28,7 @@ A test case:
 #lang scheme/unit
 
 (require mzlib/class
-         "sig.ss"
+         "sig.rkt"
          scheme/path
          scheme/file
          net/url-sig
@@ -219,14 +219,14 @@ A test case:
                (send (get-canvas) goto-url
                      (open-input-string v)
                      (get-url)))))
-         
+
          (define/public (init-browser-status-line top-level-window)
-           (send top-level-window open-status-line 'browser:hyper.ss))
+           (send top-level-window open-status-line 'browser:hyper.rkt))
          (define/public (update-browser-status-line top-level-window s)
-           (send top-level-window update-status-line 'browser:hyper.ss s))
+           (send top-level-window update-status-line 'browser:hyper.rkt s))
          (define/public (close-browser-status-line top-level-window)
-           (send top-level-window close-status-line 'browser:hyper.ss))
-         
+           (send top-level-window close-status-line 'browser:hyper.rkt))
+
          (define/public reload
            ;; The reload function is called in a non-main thread,
            ;;  since this class is instantiated in a non-main thread.
diff --git a/collects/combinator-parser/combinator-unit.rkt b/collects/combinator-parser/combinator-unit.rkt
index 2226050bc6..516ded8985 100644
--- a/collects/combinator-parser/combinator-unit.rkt
+++ b/collects/combinator-parser/combinator-unit.rkt
@@ -1,7 +1,7 @@
 (module combinator-unit mzscheme
   
   (require "private-combinator/combinator-parser.scm"
-           "private-combinator/parser-sigs.ss")
+           "private-combinator/parser-sigs.rkt")
   
   (provide combinator-parser-tools@
            combinator-parser^ err^
diff --git a/collects/compiler/commands/ctool.rkt b/collects/compiler/commands/ctool.rkt
index b02a59452e..cf941628e8 100644
--- a/collects/compiler/commands/ctool.rkt
+++ b/collects/compiler/commands/ctool.rkt
@@ -5,8 +5,8 @@
 
 (error-print-width 512)
 
-(require (prefix-in compiler:option: "../option.ss")
-         "../compiler.ss"
+(require (prefix-in compiler:option: "../option.rkt")
+         "../compiler.rkt"
          raco/command-name
          mzlib/cmdline
          dynext/file
diff --git a/collects/compiler/commands/make.rkt b/collects/compiler/commands/make.rkt
index 74f2b85ae7..fc237ce2b8 100644
--- a/collects/compiler/commands/make.rkt
+++ b/collects/compiler/commands/make.rkt
@@ -2,7 +2,7 @@
 (require scheme/cmdline
          raco/command-name
          compiler/cm
-         "../compiler.ss"
+         "../compiler.rkt"
          dynext/file
          setup/parallel-build
          racket/match)
diff --git a/collects/compiler/comp-unit.rkt b/collects/compiler/comp-unit.rkt
index d6087aab11..27bd46d1ec 100644
--- a/collects/compiler/comp-unit.rkt
+++ b/collects/compiler/comp-unit.rkt
@@ -1,6 +1,5 @@
-
 (module comp-unit mzscheme
-  (require "private/base.ss")
+  (require "private/base.rkt")
 
   (define comp@ base@)
 
diff --git a/collects/compiler/compiler-unit.rkt b/collects/compiler/compiler-unit.rkt
index 1c1d67fc03..86001766b6 100644
--- a/collects/compiler/compiler-unit.rkt
+++ b/collects/compiler/compiler-unit.rkt
@@ -9,7 +9,7 @@
 
 (require scheme/unit
 
-         "sig.ss"
+         "sig.rkt"
          dynext/file-sig
          dynext/link-sig
          dynext/compile-sig
diff --git a/collects/compiler/compiler.rkt b/collects/compiler/compiler.rkt
index 2449e199df..aeb379927c 100644
--- a/collects/compiler/compiler.rkt
+++ b/collects/compiler/compiler.rkt
@@ -1,8 +1,7 @@
-
 (module compiler mzscheme
   (require mzlib/unit)
-  
-  (require "sig.ss")
+
+  (require "sig.rkt")
 
   (require dynext/compile-sig)
   (require dynext/link-sig)
@@ -12,11 +11,10 @@
   (require dynext/link)
   (require dynext/file)
 
-  (require "option.ss")
+  (require "option.rkt")
 
-  (require "compiler-unit.ss")
+  (require "compiler-unit.rkt")
 
   (define-values/invoke-unit/infer compiler@)
 
   (provide-signature-elements compiler^))
-
diff --git a/collects/compiler/distribute.rkt b/collects/compiler/distribute.rkt
index 22c6cfab99..f7ef699ec0 100644
--- a/collects/compiler/distribute.rkt
+++ b/collects/compiler/distribute.rkt
@@ -1,14 +1,13 @@
-
 (module distribute scheme/base
   (require scheme/file
            scheme/path
            setup/dirs
-	   mzlib/list
-	   setup/variant
-	   dynext/filename-version
-	   "private/macfw.ss"
-	   "private/windlldir.ss"
-	   "private/collects-path.ss")
+           mzlib/list
+           setup/variant
+           dynext/filename-version
+           "private/macfw.rkt"
+           "private/windlldir.rkt"
+           "private/collects-path.rkt")
 
   (provide assemble-distribution)
 
diff --git a/collects/compiler/embed-unit.rkt b/collects/compiler/embed-unit.rkt
index f93f3328fc..dabab2df69 100644
--- a/collects/compiler/embed-unit.rkt
+++ b/collects/compiler/embed-unit.rkt
@@ -1,27 +1,26 @@
-
 (module embed-unit scheme/base
   (require scheme/unit
-	   scheme/path
+           scheme/path
            scheme/file
-	   scheme/port
-	   scheme/promise
+           scheme/port
+           scheme/promise
            syntax/moddep
            syntax/modcollapse
            xml/plist
            setup/dirs
            setup/variant
-	   "embed-sig.ss"
-	   "private/winicon.ss"
-           "private/winsubsys.ss"
-	   "private/macfw.ss"
-	   "private/mach-o.ss"
-	   "private/elf.ss"
-	   "private/windlldir.ss"
-	   "private/collects-path.ss"
+           "embed-sig.rkt"
+           "private/winicon.rkt"
+           "private/winsubsys.rkt"
+           "private/macfw.rkt"
+           "private/mach-o.rkt"
+           "private/elf.rkt"
+           "private/windlldir.rkt"
+           "private/collects-path.rkt"
            "find-exe.rkt")
-  
+
   (provide compiler:embed@)
-  
+
   (define-unit compiler:embed@
     (import)
     (export compiler:embed^)
@@ -1361,4 +1360,3 @@
         [(list? p) (map mac-mred-collects-path-adjust p)]
         [(relative-path? p) (build-path 'up 'up 'up p)]
         [else p]))))
-
diff --git a/collects/compiler/embed.rkt b/collects/compiler/embed.rkt
index 7db0b37248..066c2309ec 100644
--- a/collects/compiler/embed.rkt
+++ b/collects/compiler/embed.rkt
@@ -2,10 +2,10 @@
 (require scheme/unit
          scheme/contract)
 
-(require "sig.ss")
+(require "sig.rkt")
 
-(require "embed-unit.ss"
-         "embed-sig.ss")
+(require "embed-unit.rkt"
+         "embed-sig.rkt")
 
 (define-values/invoke-unit/infer compiler:embed@)
 
diff --git a/collects/compiler/info.rkt b/collects/compiler/info.rkt
index 533a10d313..80f07715b5 100644
--- a/collects/compiler/info.rkt
+++ b/collects/compiler/info.rkt
@@ -2,5 +2,5 @@
 
 (define scribblings '(("cffi.scrbl" () (legacy))))
 
-(define mzscheme-launcher-libraries (list "main.ss"))
+(define mzscheme-launcher-libraries (list "main.rkt"))
 (define mzscheme-launcher-names (list "mzc"))
diff --git a/collects/compiler/main.rkt b/collects/compiler/main.rkt
index 5ee5bf390f..f8df28abf7 100644
--- a/collects/compiler/main.rkt
+++ b/collects/compiler/main.rkt
@@ -5,11 +5,11 @@
 ;;  by the code in this collection. Other modes are handled
 ;;  by other collections, such as MzLib and dynext.
 ;; If you are interested Scheme->C part of mzc, look in
-;;  driver.ss, which is the `main' file for the compiler.
+;;  "private/driver.rkt", which is the `main' file for the compiler.
 
 ;; Different compilation modes are driven by dynamically
 ;;  linking in appropriate libraries. This is handled
-;;  by compiler.ss.
+;;  by "compiler.rkt".
 
 ;; See manual for information about the Scheme-level interface
 ;;  provided by this collection.
@@ -21,8 +21,8 @@
 
 (error-print-width 512)
 
-(require (prefix-in compiler:option: "option.ss"))
-(require "compiler.ss")
+(require (prefix-in compiler:option: "option.rkt")
+         "compiler.rkt")
 
 ;; Read argv array for arguments and input file name
 (require mzlib/cmdline
diff --git a/collects/compiler/option-unit.rkt b/collects/compiler/option-unit.rkt
index ebbabab537..f7e462411c 100644
--- a/collects/compiler/option-unit.rkt
+++ b/collects/compiler/option-unit.rkt
@@ -1,8 +1,7 @@
-
 #lang mzscheme
 
 (require mzlib/unit)
-(require "sig.ss")
+(require "sig.rkt")
 
 (provide compiler:option@)
 
diff --git a/collects/compiler/option.rkt b/collects/compiler/option.rkt
index f9f7f9cc12..86d93efb59 100644
--- a/collects/compiler/option.rkt
+++ b/collects/compiler/option.rkt
@@ -1,9 +1,8 @@
-
 (module option mzscheme
   (require mzlib/unit)
 
-  (require "sig.ss")
-  (require "option-unit.ss")
+  (require "sig.rkt"
+           "option-unit.rkt")
 
   (define-values/invoke-unit/infer compiler:option@)
 
diff --git a/collects/compiler/private/analyze.rkt b/collects/compiler/private/analyze.rkt
index 29a5ff5eed..6f0726b4e5 100644
--- a/collects/compiler/private/analyze.rkt
+++ b/collects/compiler/private/analyze.rkt
@@ -1,13 +1,13 @@
 ;; lexical analysis phase of the compiler
 ;; (c) 1996-1997 Sebastian Good
-;; (c) 1997-2001 PLT
+;; (c) 1997-2011 PLT Scheme Inc
 
 ;; For closures, variable sets, such as the free variables,
 ;;  are computed.
 ;; Constants are transformed into varrefs to top-level
 ;;  constant definitions. A list of these is kept, and
 ;;  code is generated to create the constants and prefixed
-;;  onto the output code. See also const.ss.
+;;  onto the output code. See also "const.rkt".
 ;; Global and primitive varrefs are collected into a list,
 ;;  so they can all be looked up once.
 ;; Letrec expressions that don't just bind procedures are
@@ -40,13 +40,13 @@
 
 (module analyze mzscheme
   (require mzlib/unit
-	  mzlib/list
-	  mzlib/etc)
+           mzlib/list
+           mzlib/etc)
 
   (require syntax/zodiac-sig)
 
-  (require "sig.ss")
-  (require "../sig.ss")
+  (require "sig.rkt"
+           "../sig.rkt")
 
   (provide analyze@)
   (define-unit analyze@
diff --git a/collects/compiler/private/anorm.rkt b/collects/compiler/private/anorm.rkt
index a77b587116..b69094b8c4 100644
--- a/collects/compiler/private/anorm.rkt
+++ b/collects/compiler/private/anorm.rkt
@@ -1,6 +1,6 @@
 ;; A-Normalizer
 ;; (c) 1996-7 Sebastian Good
-;; (c) 1997-8 PLT, Rice University
+;; (c) 1997-2011 PLT Scheme Inc
 
 ; This file contains an "a-normalizer" for Zodiac abstract
 ;  syntax trees for Scheme.
@@ -34,13 +34,13 @@
 
 (module anorm mzscheme
   (require mzlib/unit
-	  mzlib/list
-	  mzlib/etc)
+           mzlib/list
+           mzlib/etc)
 
   (require syntax/zodiac-sig)
 
-  (require "sig.ss")
-  (require "../sig.ss")
+  (require "sig.rkt"
+           "../sig.rkt")
 
   (provide anorm@)
   (define-unit anorm@
diff --git a/collects/compiler/private/base.rkt b/collects/compiler/private/base.rkt
index 53d9a8b1ad..e7c0650027 100644
--- a/collects/compiler/private/base.rkt
+++ b/collects/compiler/private/base.rkt
@@ -1,35 +1,34 @@
-
 (module base mzscheme
   (require mzlib/unit)
 
-  (require "../sig.ss")
-  (require "sig.ss")
+  (require "../sig.rkt"
+           "sig.rkt")
 
   (require syntax/zodiac-sig
-	   syntax/zodiac-unit)
+           syntax/zodiac-unit)
 
   (require dynext/file-sig
-	   dynext/link-sig
-	   dynext/compile-sig)
+           dynext/link-sig
+           dynext/compile-sig)
 
-  (require "zlayer.ss"
-	   "library.ss"
-	   "cstructs.ss"
-	   "prephase.ss"
-	   "anorm.ss"
-	   "const.ss"
-	   "known.ss"
-	   "analyze.ss"
-	   "lift.ss"
-	   "closure.ss"
-	   "vehicle.ss"
-	   "rep.ss"
-	   "vmscheme.ss"
-	   "vmphase.ss"
-	   "vmopt.ss"
-	   "vm2c.ss"
-	   "toplevel.ss"
-	   "driver.ss")
+  (require "zlayer.rkt"
+           "library.rkt"
+           "cstructs.rkt"
+           "prephase.rkt"
+           "anorm.rkt"
+           "const.rkt"
+           "known.rkt"
+           "analyze.rkt"
+           "lift.rkt"
+           "closure.rkt"
+           "vehicle.rkt"
+           "rep.rkt"
+           "vmscheme.rkt"
+           "vmphase.rkt"
+           "vmopt.rkt"
+           "vm2c.rkt"
+           "toplevel.rkt"
+           "driver.rkt")
 
   ;; The core Scheme->C compiler linkage, including everything
   ;;  that's common to MrSpidey and non-MrSpidey compilation.
diff --git a/collects/compiler/private/closure.rkt b/collects/compiler/private/closure.rkt
index fc885eb553..1a79c4a8e5 100644
--- a/collects/compiler/private/closure.rkt
+++ b/collects/compiler/private/closure.rkt
@@ -1,6 +1,6 @@
 ;; collect closure-making expressions
 ;; (c) 1996-1997 Sebastian Good
-;; (c) 1997-2001 PLT
+;; (c) 1997-2011 PLT Scheme, Inc
 
 ;; Closure-making expressions, such as lambda, are
 ;;  replaced with explicit make-closure AST nodes.
@@ -18,13 +18,13 @@
 
 (module closure mzscheme
   (require mzlib/unit
-	  mzlib/list
-	  mzlib/etc)
+           mzlib/list
+           mzlib/etc)
 
   (require syntax/zodiac-sig)
 
-  (require "sig.ss")
-  (require "../sig.ss")
+  (require "sig.rkt"
+           "../sig.rkt")
 
   (provide closure@)
   (define-unit closure@
@@ -85,8 +85,8 @@
 
 	    ;; Set the procedure annoation's `liftable' field to a list
 	    ;;  cotaining the sv, which indicates that it was just convrted;
-	    ;;  (list sv) is changed to sv by a pass in lift.ss.
-	    (set-procedure-code-liftable! code (list sv)) 
+	    ;;  (list sv) is changed to sv by a pass in "lift.rkt".
+	    (set-procedure-code-liftable! code (list sv))
 
 	    (if pls?
 		(begin
diff --git a/collects/compiler/private/const.rkt b/collects/compiler/private/const.rkt
index 0d67649639..49067f5918 100644
--- a/collects/compiler/private/const.rkt
+++ b/collects/compiler/private/const.rkt
@@ -12,14 +12,14 @@
 
 (module const mzscheme
   (require mzlib/unit
-	   mzlib/list
-	   mzlib/etc)
+           mzlib/list
+           mzlib/etc)
 
   (require syntax/zodiac-sig
-	   syntax/stx)
+           syntax/stx)
 
-  (require "sig.ss")
-  (require "../sig.ss")
+  (require "sig.rkt"
+           "../sig.rkt")
 
   (provide const@)
   (define-unit const@
@@ -339,7 +339,7 @@
 				  (zodiac:make-zread
 				   (datum->syntax-object
 				    #f
-				    ast ;; See vm2c.ss
+				    ast ;; See "vm2c.rkt"
 				    #f)))
 				 varref:static)]
 	   
diff --git a/collects/compiler/private/cstructs.rkt b/collects/compiler/private/cstructs.rkt
index c04084061d..6f6cfb9218 100644
--- a/collects/compiler/private/cstructs.rkt
+++ b/collects/compiler/private/cstructs.rkt
@@ -1,18 +1,18 @@
 ;; Compiler structures
 ;; (c) 1996-1997 Sebastian Good
-;; (c) 1997-2001 PLT
+;; (c) 1997-2011 PLT Scheme Inc
 
 ;; Mostly structure definitions, mostly for annotations.
 
 (module cstructs mzscheme
   (require mzlib/unit
-	  mzlib/list
-	  mzlib/etc)
+           mzlib/list
+           mzlib/etc)
 
   (require syntax/zodiac-sig)
 
-  (require "sig.ss")
-  (require "../sig.ss")
+  (require "sig.rkt"
+           "../sig.rkt")
 
   (provide cstructs@)
   (define-unit cstructs@
diff --git a/collects/compiler/private/driver.rkt b/collects/compiler/private/driver.rkt
index fbda8d607d..9576ce2812 100644
--- a/collects/compiler/private/driver.rkt
+++ b/collects/compiler/private/driver.rkt
@@ -1,6 +1,6 @@
-;; Compiler driver routines 
+;; Compiler driver routines
 ;; (c) 1996-1997 Sebastian Good
-;; (c) 1997-2001 PLT
+;; (c) 1997-2011 PLT Scheme Inc
 ;;
 ;; Scheme->C compilation Overview
 ;; ------------------------------
@@ -9,23 +9,23 @@
 ;;  each of which is implemented in its own unit:
 ;;
 ;;   1) Reading/parsing - Zodiac collection
-;;   2) Prephase - prephase.ss
-;;   3) A-normalization - anorm.ss
-;;   4) Known-value analysis - known.ss
-;;   5) Lexical analysis and inlining - analyze.ss
-;;   6) Static procedure lifting - lift.ss
-;;   7) Static procedure lifting after LWCC - lift.ss (optional)
-;;   8) Closure conversion - closure.ss
-;;   9) Closure vehicle assignment - vehicle.ss
-;;  10) Representation choosing - rep.ss
-;;  11) Scheme to virtual machine translation - vmphase.ss
-;;  12) Optimizations on VM code - vmopt.ss
-;;  13) VM to C translation - vm2c.ss
+;;   2) Prephase - "prephase.rkt"
+;;   3) A-normalization - "anorm.rkt"
+;;   4) Known-value analysis - "known.rkt"
+;;   5) Lexical analysis and inlining - "analyze.rkt"
+;;   6) Static procedure lifting - "lift.rkt"
+;;   7) Static procedure lifting after LWCC - "lift.rkt" (optional)
+;;   8) Closure conversion - "closure.rkt"
+;;   9) Closure vehicle assignment - "vehicle.rkt"
+;;  10) Representation choosing - "rep.rkt"
+;;  11) Scheme to virtual machine translation - "vmphase.rkt"
+;;  12) Optimizations on VM code - "vmopt.rkt"
+;;  13) VM to C translation - "vm2c.rkt"
 ;;
 ;; For more information about a phase, see the file
 ;;  implementing that phase.
 ;;
-;; All steps up to vmphase.ss work on a Scheme program, representated
+;; All steps up to "vmphase.rkt" work on a Scheme program, representated
 ;;  as a zodiac AST. The AST produced by zodiac is destructively
 ;;  modified by each phase (usually); mzc-specific information is
 ;;  stored in the AST as ``annotations''. At the implementation file
@@ -61,27 +61,27 @@
 
 (module driver mzscheme
   (require mzlib/unit
-	   mzlib/list
-	   mzlib/file
-	   mzlib/port
-	   mzlib/etc
-	   mzlib/pretty
-	   (prefix src2src: "../src2src.ss"))
-  
+           mzlib/list
+           mzlib/file
+           mzlib/port
+           mzlib/etc
+           mzlib/pretty
+           (prefix src2src: "../src2src.rkt"))
+
   (require syntax/zodiac-sig
-	   syntax/toplevel
-	   dynext/compile-sig
-	   dynext/link-sig
-	   dynext/file-sig
-	   setup/dirs
-           (only scheme/base 
-                 define-namespace-anchor 
+           syntax/toplevel
+           dynext/compile-sig
+           dynext/link-sig
+           dynext/file-sig
+           setup/dirs
+           (only scheme/base
+                 define-namespace-anchor
                  namespace-anchor->empty-namespace))
 
-  (require "../sig.ss"
-	   "sig.ss"
-	   "../to-core.ss"
-	   "../xform.ss")
+  (require "../sig.rkt"
+           "sig.rkt"
+           "../to-core.rkt"
+           "../xform.rkt")
 
   (provide driver@)
 
@@ -247,7 +247,7 @@
 				      expr)])
 		       (values ; use to be zodiac:syntax->zodiac here
 			(let ([p (src2src:optimize expanded #t)])
-			  '(with-output-to-file "/tmp/l.ss"
+			  '(with-output-to-file "/tmp/l.rkt"
 			     (lambda () (pretty-print (syntax-object->datum p)))
 			     'replace)
 			  (let ([opt-expanded (expand p)])
diff --git a/collects/compiler/private/known.rkt b/collects/compiler/private/known.rkt
index de307b0b5d..0d34937372 100644
--- a/collects/compiler/private/known.rkt
+++ b/collects/compiler/private/known.rkt
@@ -1,6 +1,6 @@
 ;; Known-value analysis
 ;; (c) 1996-1997 Sebastian Good
-;; (c) 1997-2001 PLT
+;; (c) 1997-2011 PLT Scheme
 
 ;; Sets the real annotation for zodiac:binding AST nodes,
 ;; setting the known? and known-val fields as possible.
@@ -22,13 +22,13 @@
 
 (module known mzscheme
   (require mzlib/unit
-	  mzlib/list
-	  mzlib/etc)
+           mzlib/list
+           mzlib/etc)
 
   (require syntax/zodiac-sig)
 
-  (require "sig.ss")
-  (require "../sig.ss")
+  (require "sig.rkt"
+           "../sig.rkt")
 
   (provide known@)
   (define-unit known@
diff --git a/collects/compiler/private/library.rkt b/collects/compiler/private/library.rkt
index b485a9a64b..b9a2c53225 100644
--- a/collects/compiler/private/library.rkt
+++ b/collects/compiler/private/library.rkt
@@ -1,15 +1,15 @@
 ;; Library of functions for the compiler
 ;; (c) 1996-7 Sebastian Good
-;; (c) 1997-8 PLT, Rice University
+;; (c) 1997-2011 PLT Scheme Inc
 
 (module library mzscheme
   (require mzlib/unit
-	  mzlib/list
-	  mzlib/etc)
+           mzlib/list
+           mzlib/etc)
 
   (require syntax/zodiac-sig)
 
-  (require "sig.ss")
+  (require "sig.rkt")
 
   (provide library@)
   (define-unit library@
diff --git a/collects/compiler/private/lift.rkt b/collects/compiler/private/lift.rkt
index 2f407c9253..51e0a5148f 100644
--- a/collects/compiler/private/lift.rkt
+++ b/collects/compiler/private/lift.rkt
@@ -1,11 +1,11 @@
 ;; A kind of lambda-lifting
-;; (c) 1997-2001 PLT
+;; (c) 1997-2011 PLT Scheme Inc
 
 ;; Finds liftable procedures, sets their `liftable' field, and
 ;;  replaces lexical variables for liftable procedures with
 ;;  globals variables. This transformation can be applied
-;;  anytime (and multiple times) after analyze.ss and before
-;;  closure.ss.
+;;  anytime (and multiple times) after "analyze.rkt" and before
+;;  "closure.rkt".
 ;; Liftable lambdas are procedures whose free variables include only
 ;;  lexical variables bound to known-lifted procedures, primitive
 ;;  globals, and statics. (No namespace-sentsitive globals and no
@@ -22,13 +22,13 @@
 
 (module lift mzscheme
   (require mzlib/unit
-	  mzlib/list
-	  mzlib/etc)
+           mzlib/list
+           mzlib/etc)
 
   (require syntax/zodiac-sig)
 
-  (require "sig.ss")
-  (require "../sig.ss")
+  (require "sig.rkt"
+           "../sig.rkt")
 
   (provide lift@)
   (define-unit lift@
diff --git a/collects/compiler/private/macfw.rkt b/collects/compiler/private/macfw.rkt
index 0706d6686f..2f9ef2b71e 100644
--- a/collects/compiler/private/macfw.rkt
+++ b/collects/compiler/private/macfw.rkt
@@ -1,12 +1,11 @@
-
 (module macfw mzscheme
-  (require "mach-o.ss"
-	   mzlib/string
-	   mzlib/process)
+  (require "mach-o.rkt"
+           mzlib/string
+           mzlib/process)
 
   (provide update-framework-path
-	   get-current-framework-path
-	   update-framework-path/cmdline)
+           get-current-framework-path
+           update-framework-path/cmdline)
 
   (define (update-framework-path/cmdline)
     (let ([v (current-command-line-arguments)])
diff --git a/collects/compiler/private/prephase.rkt b/collects/compiler/private/prephase.rkt
index ccfa65ffd1..29334c3a58 100644
--- a/collects/compiler/private/prephase.rkt
+++ b/collects/compiler/private/prephase.rkt
@@ -1,6 +1,6 @@
 ;; pre-compilation scan
 ;; (c) 1996-1997 Sebastian Good
-;; (c) 1997-2001 PLT
+;; (c) 1997-2011 PLT Scheme Inc
 
 ; Notes mutability of lexical variables.
 ; Performs a few very-high-level optimizations, such as
@@ -44,8 +44,8 @@
 
   (require syntax/zodiac-sig)
 
-  (require "sig.ss")
-  (require "../sig.ss")
+  (require "sig.rkt"
+           "../sig.rkt")
 
   (provide prephase@)
   (define-unit prephase@
diff --git a/collects/compiler/private/rep.rkt b/collects/compiler/private/rep.rkt
index 6867da0b6f..eb3d8924a3 100644
--- a/collects/compiler/private/rep.rkt
+++ b/collects/compiler/private/rep.rkt
@@ -1,6 +1,6 @@
 ;; Representation choosing phase of the compiler
 ;; (c) 1996-1997 Sebastian Good
-;; (c) 1997-201 PLT
+;; (c) 1997-2011 PLT Scheme Inc
 
 ;; Chooses the representation of all bindings, and also
 ;;  closures.
@@ -19,8 +19,8 @@
 
   (require syntax/zodiac-sig)
 
-  (require "sig.ss")
-  (require "../sig.ss")
+  (require "sig.rkt"
+           "../sig.rkt")
 
   (provide rep@)
   (define-unit rep@
diff --git a/collects/compiler/private/sig.rkt b/collects/compiler/private/sig.rkt
index b0986bab0d..94b6f171c7 100644
--- a/collects/compiler/private/sig.rkt
+++ b/collects/compiler/private/sig.rkt
@@ -1,9 +1,8 @@
-
 (module sig mzscheme
   (require mzlib/unit)
 
-  (require "../sig.ss")
-  (require syntax/zodiac-sig)
+  (require "../sig.rkt"
+           syntax/zodiac-sig)
 
   (define for-syntax-in-env-stx #'for-syntax-in-env)
   (provide for-syntax-in-env-stx)
diff --git a/collects/compiler/private/toplevel.rkt b/collects/compiler/private/toplevel.rkt
index 214a12c412..42806fa6cf 100644
--- a/collects/compiler/private/toplevel.rkt
+++ b/collects/compiler/private/toplevel.rkt
@@ -1,11 +1,11 @@
 ;; routines for top-level entities
 ;; (c) 1996-1997 Sebastian Good
-;; (c) 1997-2001 PLT
+;; (c) 1997-2011 PLT Scheme Inc
 
 (module toplevel mzscheme
   (require mzlib/unit)
 
-  (require "sig.ss")
+  (require "sig.rkt")
 
   (provide toplevel@)
   (define-unit toplevel@
diff --git a/collects/compiler/private/vehicle.rkt b/collects/compiler/private/vehicle.rkt
index f592c803ce..7032142e61 100644
--- a/collects/compiler/private/vehicle.rkt
+++ b/collects/compiler/private/vehicle.rkt
@@ -1,6 +1,6 @@
 ;; vehicle choosing phase for closures
 ;; (c) 1996-1997 Sebastian Good
-;; (c) 1997-2001 PLT
+;; (c) 1997-2011 PLT Scheme Inc
 
 ; Assign closures to ``vehicles'', and collect information for
 ;  Racket about the closures.
@@ -24,8 +24,8 @@
 
   (require syntax/zodiac-sig)
 
-  (require "sig.ss")
-  (require "../sig.ss")
+  (require "sig.rkt"
+           "../sig.rkt")
 
   (provide vehicle@)
   (define-unit vehicle@
diff --git a/collects/compiler/private/vm2c.rkt b/collects/compiler/private/vm2c.rkt
index 60b09b439b..99312b9503 100644
--- a/collects/compiler/private/vm2c.rkt
+++ b/collects/compiler/private/vm2c.rkt
@@ -4,13 +4,13 @@
 
 (module vm2c mzscheme
   (require mzlib/unit
-	   mzlib/list)
+           mzlib/list)
 
   (require syntax/zodiac-sig
-	   syntax/primitives)
+           syntax/primitives)
 
-  (require "sig.ss")
-  (require "../sig.ss")
+  (require "sig.rkt"
+           "../sig.rkt")
 
   (provide vm2c@)
   (define-unit vm2c@
diff --git a/collects/compiler/private/vmopt.rkt b/collects/compiler/private/vmopt.rkt
index 4a43fa2df2..1d6bfa3795 100644
--- a/collects/compiler/private/vmopt.rkt
+++ b/collects/compiler/private/vmopt.rkt
@@ -1,21 +1,21 @@
 ;; VM Optimization pass
 ;; (c) 1996-1997 Sebastian Good
-;; (c) 1997-201 PLT
+;; (c) 1997-2011 PLT Scheme Inc
 
 ;; This pass only allows T & V statements to be expanded into multiple
 ;; statments there is not a mechanism to expand R, A, or L
-;; expressions. (See vmscheme.ss.)
+;; expressions. (See "vmscheme.rkt".)
 
 (module vmopt mzscheme
-  
+
   (require mzlib/unit
-	  mzlib/list
-	  mzlib/etc)
+           mzlib/list
+           mzlib/etc)
 
   (require syntax/zodiac-sig)
 
-  (require "sig.ss")
-  (require "../sig.ss")
+  (require "sig.rkt"
+           "../sig.rkt")
 
   (provide vmopt@)
   (define-unit vmopt@
diff --git a/collects/compiler/private/vmphase.rkt b/collects/compiler/private/vmphase.rkt
index acbeb71a80..1321cf8b6c 100644
--- a/collects/compiler/private/vmphase.rkt
+++ b/collects/compiler/private/vmphase.rkt
@@ -1,24 +1,24 @@
 ;; Scheme->VMScheme conversion phase
 ;; (c) 1996-1997 Sebastian Good
-;; (c) 1997-2001 PLT, Rice University
+;; (c) 1997-2011 PLT Scheme Inc
 
 ;; Takes a zodiac:* AST and produces a vm:* AST. Some
 ;;  zodiac:* AST elements are still used, particularly
-;;  bindings and varrefs. 
+;;  bindings and varrefs.
 
 ;; Well-applied known primitives are sometimes compiled
 ;;  to macro uses (where the macros are defined in mzc.h).
 
-(module vmphase mzscheme 
+(module vmphase mzscheme
   (require mzlib/unit
-	   mzlib/list
-	   mzlib/etc)
+           mzlib/list
+           mzlib/etc)
 
   (require syntax/zodiac-sig
-	   syntax/primitives)
+           syntax/primitives)
 
-  (require "sig.ss"
-	   "../sig.ss")
+  (require "sig.rkt"
+           "../sig.rkt")
 
   (provide vmphase@)
   (define-unit vmphase@
diff --git a/collects/compiler/private/vmscheme.rkt b/collects/compiler/private/vmscheme.rkt
index d1c966f8b8..a0b402412c 100644
--- a/collects/compiler/private/vmscheme.rkt
+++ b/collects/compiler/private/vmscheme.rkt
@@ -1,19 +1,19 @@
 ;; VM-Scheme
 ;; (c) 1996-1997 Sebastian Good
-;; (c) 1997-2001 PLT
+;; (c) 1997-2011 PLT Scheme Inc
 
 ;; Mostly structure definitions for VM AST nodes.
 
 (module vmscheme mzscheme
   
   (require mzlib/unit
-	   mzlib/list
-	   mzlib/etc)
+           mzlib/list
+           mzlib/etc)
 
   (require syntax/zodiac-sig)
 
-  (require "sig.ss")
-  (require "../sig.ss")
+  (require "sig.rkt"
+           "../sig.rkt")
 
   (provide vmscheme@)
   (define-unit vmscheme@
diff --git a/collects/compiler/private/windlldir.rkt b/collects/compiler/private/windlldir.rkt
index 927283840a..afe93380fc 100644
--- a/collects/compiler/private/windlldir.rkt
+++ b/collects/compiler/private/windlldir.rkt
@@ -1,21 +1,18 @@
-
 (module windlldir mzscheme
   (require mzlib/port
-	   "winutf16.ss")
+           "winutf16.rkt")
 
   (provide update-dll-dir
            get-current-dll-dir)
 
   (define label (byte-regexp (bytes->utf-16-bytes #"dLl dIRECTORy:")))
   (define max-dir-len (* 512 2)) ; sizeof(wchar_t) is 2
-  
+
   (define (update-dll-dir dest path)
     (let ([path-bytes (bytes->utf-16-bytes
-		       (if (eq? path #t)
-			   #"<system>"
-			   (if (path? path)
-			       (path->bytes path)
-			       (string->bytes/locale path))))])
+                       (cond [(eq? path #t) #"<system>"]
+                             [(path? path) (path->bytes path)]
+                             [else (string->bytes/locale path)]))])
       (unless ((bytes-length path-bytes) . <= . max-dir-len)
         (error 'update-dll-dir "path too long: ~e" path))
       (let ([m (with-input-from-file dest
diff --git a/collects/compiler/private/zlayer.rkt b/collects/compiler/private/zlayer.rkt
index b1564cc34f..ea666b1510 100644
--- a/collects/compiler/private/zlayer.rkt
+++ b/collects/compiler/private/zlayer.rkt
@@ -1,17 +1,17 @@
 ;; Zodiac interface and library routines
 ;; (c)1996-1997 Sebastian Good
-;; (c)1997-2001 PLT
+;; (c)1997-2011 PLT Scheme Inc
 
 (module zlayer mzscheme
   (require mzlib/unit
-	  mzlib/list
-	  mzlib/etc)
-  
+           mzlib/list
+           mzlib/etc)
+
   (require syntax/zodiac-sig)
 
-  (require "../sig.ss")
-  (require "sig.ss")
-  
+  (require "../sig.rkt"
+           "sig.rkt")
+
   (provide zlayer@)
   (define-unit zlayer@
       (import (prefix compiler:option: compiler:option^)
diff --git a/collects/compiler/xform.rkt b/collects/compiler/xform.rkt
index 451ab30159..51e354883c 100644
--- a/collects/compiler/xform.rkt
+++ b/collects/compiler/xform.rkt
@@ -2,7 +2,7 @@
 
 (require dynext/compile
          setup/dirs
-         (prefix-in xform: "private/xform.ss"))
+         (prefix-in xform: "private/xform.rkt"))
 
 (provide xform)
 
diff --git a/collects/config/config.rkt b/collects/config/config.rkt
index 33c7a47734..35b4bfefbb 100644
--- a/collects/config/config.rkt
+++ b/collects/config/config.rkt
@@ -1,7 +1,6 @@
-
-;; The config module doesn't have to use "configtab.ss";
+;; The config module doesn't have to use `setup/configtab';
 ;; it just has to have the right exports. But using
-;; "configtab.ss" makes it easier to generate the
+;; `setup/configtab' makes it easier to generate the
 ;; code at install time.
 (module config setup/configtab
   ;; An empty table means that all defaults apply
diff --git a/collects/config/main.rkt b/collects/config/main.rkt
index 535316ba27..8a028e3ed1 100644
--- a/collects/config/main.rkt
+++ b/collects/config/main.rkt
@@ -1,4 +1,4 @@
 #lang racket/base
 
-(require "config.ss")
-(provide (all-from-out "config.ss"))
+(require "config.rkt")
+(provide (all-from-out "config.rkt"))
diff --git a/collects/deinprogramm/DMdA-advanced-reader.rkt b/collects/deinprogramm/DMdA-advanced-reader.rkt
index 38eb173ee0..f557901444 100644
--- a/collects/deinprogramm/DMdA-advanced-reader.rkt
+++ b/collects/deinprogramm/DMdA-advanced-reader.rkt
@@ -4,4 +4,3 @@
          (rename-out (-read read)))
 (define -read-syntax (make-read-syntax '(lib "DMdA-advanced.ss" "deinprogramm")))
 (define -read (make-read '(lib "DMdA-advanced.ss" "deinprogramm")))
-
diff --git a/collects/deinprogramm/DMdA-assignments-reader.rkt b/collects/deinprogramm/DMdA-assignments-reader.rkt
index ac06aa6167..32e23f80ed 100644
--- a/collects/deinprogramm/DMdA-assignments-reader.rkt
+++ b/collects/deinprogramm/DMdA-assignments-reader.rkt
@@ -4,5 +4,3 @@
          (rename-out (-read read)))
 (define -read-syntax (make-read-syntax '(lib "DMdA-assignments.ss" "deinprogramm")))
 (define -read (make-read '(lib "DMdA-assignments.ss" "deinprogramm")))
-
-
diff --git a/collects/deinprogramm/DMdA-beginner-reader.rkt b/collects/deinprogramm/DMdA-beginner-reader.rkt
index 42c7394f7b..5c3424e658 100644
--- a/collects/deinprogramm/DMdA-beginner-reader.rkt
+++ b/collects/deinprogramm/DMdA-beginner-reader.rkt
@@ -2,6 +2,5 @@
 (require deinprogramm/DMdA-reader)
 (provide (rename-out (-read-syntax read-syntax))
          (rename-out (-read read)))
-(define -read-syntax (make-read-syntax '(lib "DMdA-beginner.ss" "deinprogramm")))
-(define -read (make-read '(lib "DMdA-beginner.ss" "deinprogramm")))
-
+(define -read-syntax (make-read-syntax '(lib "DMdA-beginner.rkt" "deinprogramm")))
+(define -read (make-read '(lib "DMdA-beginner.rkt" "deinprogramm")))
diff --git a/collects/deinprogramm/DMdA-vanilla-reader.rkt b/collects/deinprogramm/DMdA-vanilla-reader.rkt
index 6c466e37ec..c84426c5d5 100644
--- a/collects/deinprogramm/DMdA-vanilla-reader.rkt
+++ b/collects/deinprogramm/DMdA-vanilla-reader.rkt
@@ -1,7 +1,6 @@
 (module DMdA-vanilla-reader mzscheme
-  (require "DMdA-reader.ss")
+  (require "DMdA-reader.rkt")
   (provide (rename -read-syntax read-syntax)
            (rename -read read))
   (define -read-syntax (make-read-syntax '(lib "DMdA-vanilla.ss" "deinprogramm")))
   (define -read (make-read '(lib "DMdA-vanilla.ss" "deinprogramm"))))
-
diff --git a/collects/deinprogramm/DMdA.rkt b/collects/deinprogramm/DMdA.rkt
index c36ad846f6..d9382c29bf 100644
--- a/collects/deinprogramm/DMdA.rkt
+++ b/collects/deinprogramm/DMdA.rkt
@@ -439,10 +439,10 @@
 		  unit combine))
 	 (current-continuation-marks)))))))
 
-;; This is copied from collects/lang/private/beginner-funs.ss
+;; This is copied from collects/lang/private/beginner-funs.rkt
 ;; Test-suite support (require is really an effect
 ;;  to make sure that it's loaded)
-(require "test-suite.ss")
+(require "test-suite.rkt")
 
 (define-for-syntax (binding-in-this-module? b)
   (and (list? b)
@@ -932,7 +932,7 @@
 (define unspecific (signature unspecific %unspecific))
 (define any (signature any %any))
 
-;; aus collects/lang/private/teach.ss
+;; aus collects/lang/private/teach.rkt
 
 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; dots (.. and ... and .... and ..... and ......)
diff --git a/collects/deinprogramm/deinprogramm-langs.rkt b/collects/deinprogramm/deinprogramm-langs.rkt
index d01dc1b6c0..20f243d2ee 100644
--- a/collects/deinprogramm/deinprogramm-langs.rkt
+++ b/collects/deinprogramm/deinprogramm-langs.rkt
@@ -36,7 +36,7 @@
 
   (require mzlib/pconvert-prop)
 
-  (require "convert-explicit.ss")
+  (require "convert-explicit.rkt")
 
   (require (only-in mrlib/syntax-browser render-syntax/snip))
   
@@ -53,7 +53,7 @@
   (define generic-proc
     (procedure-rename void '?))
 
-  ;; adapted from collects/drscheme/private/main.ss
+  ;; adapted from collects/drracket/private/main.rkt
   (preferences:set-default 'drscheme:deinprogramm:last-set-teachpacks
                            '() 
                            (lambda (x)
@@ -168,7 +168,7 @@
           (define/override (on-execute settings run-in-user-thread)
             (let ([drs-namespace (current-namespace)]
                   [scheme-test-module-name
-                   ((current-module-name-resolver) '(lib "test-engine/scheme-tests.ss") #f #f)]
+                   ((current-module-name-resolver) '(lib "test-engine/scheme-tests.rkt") #f #f)]
                   [scheme-signature-module-name
                    ((current-module-name-resolver) '(lib "deinprogramm/signature/signature-german.rkt") #f #f)])
               (run-in-user-thread
@@ -211,7 +211,7 @@
 		 )))
             (super on-execute settings run-in-user-thread)
 
-	    ;; DeinProgramm addition, copied from language.ss
+	    ;; DeinProgramm addition, copied from language.rkt
 	    (run-in-user-thread
 	     (lambda ()
 	       (global-port-print-handler
@@ -261,7 +261,7 @@
       (define drscheme-inspector (current-inspector))
 
       ;; FIXME: brittle, mimics drscheme-secrets
-      ;; as declared in lang/htdp-langs.ss.
+      ;; as declared in lang/htdp-langs.rkt.
       ;; Is it even needed for DeinProgramm langs?
       ;; Only used by htdp/hangman teachpack.
       (define (ensure-drscheme-secrets-declared drs-namespace)
@@ -278,13 +278,13 @@
 
 
       ;; {
-      ;;   all this copied from collects/drscheme/private/language.ss
+      ;;   all this copied from collects/drracket/private/language.rkt
 
       ;; stepper-convert-value : TST settings -> TST 
      (define (stepper-convert-value value settings)
         (define ((leave-snips-alone-hook sh) expr basic-convert sub-convert)
           (if (or (is-a? expr snip%)
-                  ;; FIXME: internal in language.ss (to-snip-value? expr)
+                  ;; FIXME: internal in language.rkt (to-snip-value? expr)
                   )
             expr
             (sh expr basic-convert sub-convert)))
@@ -723,7 +723,7 @@
                        (string-append no-ext-name ".scm")]
                       [(file-exists? no-ext-name)
                        no-ext-name]
-                      [else (error 'deinprogramm-lang.ss "could not find language filename ~s" no-ext-name)])]
+                      [else (error 'deinprogramm-lang.rkt "could not find language filename ~s" no-ext-name)])]
                    [base-dir (let-values ([(base _1 _2) (split-path full-name)]) base)]
                    [stx
                     (call-with-input-file full-name
@@ -768,7 +768,7 @@
             (let ([reader (get-reader)] ;; DeinProgramm addition:
 					;; needed for test boxes; see
 					;; the code in
-					;; collects/drscheme/private/language.ss
+					;; collects/drracket/private/language.rkt
 		  [start? #t]
                   [done? #f])
               (λ ()
@@ -1130,7 +1130,7 @@
 
       ;; make-print-convert-hook:
       ;;   simple-settings -> (TST (TST -> TST) (TST -> TST) -> TST)
-      ;; this code copied from various locations in language.ss and rep.ss
+      ;; this code copied from various locations in language.rkt and rep.rkt
       (define (make-print-convert-hook simple-settings)
 	(lambda (exp basic-convert sub-convert)
 	  (cond
@@ -1370,7 +1370,7 @@
         (add-deinprogramm-language
          (instantiate (make-deinprogramm-language% 'write 'explicit) ()
 	   (one-line-summary "Die Macht der Abstraktion - Anfänger")
-	   (module '(lib "deinprogramm/DMdA-beginner.ss"))
+	   (module '(lib "deinprogramm/DMdA-beginner.rkt"))
            (manual #"DMdA-beginner")
 	   (language-position (list (string-constant teaching-languages)
 				    "DeinProgramm" "Die Macht der Abstraktion - Anfänger"))
@@ -1379,13 +1379,13 @@
            (sharing-printing #f)
            (abbreviate-cons-as-list #t)
            (allow-sharing? #f)
-	   (reader-module '(lib "DMdA-beginner-reader.ss" "deinprogramm"))
+	   (reader-module '(lib "DMdA-beginner-reader.rkt" "deinprogramm"))
 	   (stepper:supported #t)))
 	
 	(add-deinprogramm-language
          (instantiate (make-deinprogramm-language% 'write 'explicit) ()
 	   (one-line-summary "Die Macht der Abstraktion")
-	   (module '(lib "deinprogramm/DMdA-vanilla.ss"))
+	   (module '(lib "deinprogramm/DMdA-vanilla.rkt"))
            (manual #"DMdA-vanilla")
 	   (language-position (list (string-constant teaching-languages)
 				    "DeinProgramm" "Die Macht der Abstraktion"))
@@ -1394,13 +1394,13 @@
            (sharing-printing #f)
            (abbreviate-cons-as-list #t)
            (allow-sharing? #f)
-	   (reader-module '(lib "DMdA-vanilla-reader.ss" "deinprogramm"))
+	   (reader-module '(lib "DMdA-vanilla-reader.rkt" "deinprogramm"))
 	   (stepper:supported #t)))
 
         (add-deinprogramm-language
          (instantiate (make-deinprogramm-language% 'write 'explicit) ()
 	   (one-line-summary "Die Macht der Abstraktion mit Zuweisungen")
-	   (module '(lib "deinprogramm/DMdA-assignments.ss"))
+	   (module '(lib "deinprogramm/DMdA-assignments.rkt"))
            (manual #"DMdA-assignments")
 	   (language-position (list (string-constant teaching-languages)
 				    "DeinProgramm" "Die Macht der Abstraktion mit Zuweisungen"))
@@ -1409,14 +1409,14 @@
            (sharing-printing #t)
            (abbreviate-cons-as-list #t)
            (allow-sharing? #t)
-	   (reader-module '(lib "DMdA-assignments-reader.ss" "deinprogramm"))
+	   (reader-module '(lib "DMdA-assignments-reader.rkt" "deinprogramm"))
 	   (stepper:supported #f)
 	   (debugger:supported #t)))
 
         (add-deinprogramm-language
          (instantiate (make-deinprogramm-language% 'write 'datum) ()
 	   (one-line-summary "Die Macht der Abstraktion - fortgeschritten")
-	   (module '(lib "deinprogramm/DMdA-advanced.ss"))
+	   (module '(lib "deinprogramm/DMdA-advanced.rkt"))
            (manual #"DMdA-advanced")
 	   (language-position (list (string-constant teaching-languages)
 				    "DeinProgramm" "Die Macht der Abstraktion - fortgeschritten"))
@@ -1425,6 +1425,6 @@
            (sharing-printing #t)
            (abbreviate-cons-as-list #t)
            (allow-sharing? #t)
-	   (reader-module '(lib "DMdA-advanced-reader.ss" "deinprogramm"))
+	   (reader-module '(lib "DMdA-advanced-reader.rkt" "deinprogramm"))
 	   (stepper:supported #f)
 	   (debugger:supported #t))))))
diff --git a/collects/deinprogramm/image.rkt b/collects/deinprogramm/image.rkt
index 525ee8d488..c5dc890ea1 100644
--- a/collects/deinprogramm/image.rkt
+++ b/collects/deinprogramm/image.rkt
@@ -3,7 +3,7 @@
 #|
 
 The test suite for this code is in
-plt/collects/tests/deinprogramm/image.ss
+collects/tests/deinprogramm/image.rkt
 
 |#
 
diff --git a/collects/deinprogramm/info.rkt b/collects/deinprogramm/info.rkt
index 567899bcdc..41772e6d7c 100644
--- a/collects/deinprogramm/info.rkt
+++ b/collects/deinprogramm/info.rkt
@@ -3,7 +3,7 @@
 
 (define name "DeinProgramm")
 
-(define tools '("deinprogramm-langs.ss"))
+(define tools '("deinprogramm-langs.rkt"))
 
 (define tool-icons '(("logo-small.png" "deinprogramm")))
 (define tool-names '("DeinProgramm"))
diff --git a/collects/deinprogramm/line3d.rkt b/collects/deinprogramm/line3d.rkt
index 23a0e55cf4..3e4f7b8330 100644
--- a/collects/deinprogramm/line3d.rkt
+++ b/collects/deinprogramm/line3d.rkt
@@ -1,13 +1,13 @@
 (module line3d mzscheme
-  (require "world.ss"
-	   "define-record-procedures.ss")
-  (require (only "DMdA-vanilla.ss"
-		 empty make-pair empty?
-		 first rest))
+  (require "world.rkt"
+           "define-record-procedures.rkt")
+  (require (only "DMdA-vanilla.rkt"
+                 empty make-pair empty?
+                 first rest))
   (provide make-vec3
-  				 vec3-x
-  				 vec3-y
-  				 vec3-z
+           vec3-x
+           vec3-y
+           vec3-z
            add-vec3
            sub-vec3
            mult-vec3
@@ -55,6 +55,6 @@
            transform-primitive-list
            render-scene
            )
-                   
-  (require (lib "include.ss"))
+
+  (require mzlib/include)
   (include "line3d.scm"))
diff --git a/collects/deinprogramm/quickcheck/info.rkt b/collects/deinprogramm/quickcheck/info.rkt
index c0f71d5ab8..f5bf7c1c8f 100644
--- a/collects/deinprogramm/quickcheck/info.rkt
+++ b/collects/deinprogramm/quickcheck/info.rkt
@@ -1,4 +1,4 @@
-(module info (lib "infotab.ss" "setup")
+(module info setup/infotab
   (define name "DeinProgramm - QuickCheck")
 
   (define compile-omit-files
diff --git a/collects/deinprogramm/quickcheck/quickcheck.rkt b/collects/deinprogramm/quickcheck/quickcheck.rkt
index 2e34d72928..7f4338b9d4 100644
--- a/collects/deinprogramm/quickcheck/quickcheck.rkt
+++ b/collects/deinprogramm/quickcheck/quickcheck.rkt
@@ -28,7 +28,7 @@
 	 )
 (require srfi/9
 	 racket/promise
-	 "random.ss")
+	 "random.rkt")
 
 (provide exn:assertion-violation?
 	 exn:assertion-violation-who
diff --git a/collects/deinprogramm/run-dmda-code.rkt b/collects/deinprogramm/run-dmda-code.rkt
index 1a6604d181..f0a958a91f 100644
--- a/collects/deinprogramm/run-dmda-code.rkt
+++ b/collects/deinprogramm/run-dmda-code.rkt
@@ -1,8 +1,5 @@
 (module run-dmda-code mzscheme
-  (require (lib "mred.ss" "mred")
-	   (lib "class.ss")
-	   (lib "match.ss")
-	   (lib "modread.ss" "syntax"))
+  (require mred/mred mzlib/class mzlib/match syntax/modread)
 
   (define (run-dmda-file filename)
     (let ((p (open-input-graphical-file/fixed filename))
@@ -20,7 +17,7 @@
 			 ((?module ?name ?language ?body ...)
 			  (syntax
 			   (?module ?name ?language 
-				    (require (lib "testing.ss" "htdp"))
+				    (require (lib "testing.rkt" "htdp"))
 				    ?body ...)))))
 		      (module-ized-code
 		       (check-module-form pimped-code expected-module-name filename)))
diff --git a/collects/deinprogramm/world.rkt b/collects/deinprogramm/world.rkt
index 47cecb1634..ab442b8bb0 100644
--- a/collects/deinprogramm/world.rkt
+++ b/collects/deinprogramm/world.rkt
@@ -2,7 +2,7 @@
 
 ;; Mon Mar 27 10:29:28 EST 2006: integrated Felix's mouse events
 ;; Wed Jan 25 13:38:42 EST 2006: on-redraw: proc is now called on installation
-;; Tue Jan  3 11:17:50 EST 2006: changed add-line behavior in world.ss 
+;; Tue Jan  3 11:17:50 EST 2006: changed add-line behavior in world.rkt
 ;; Sat Dec 10 19:39:03 EST 2005: fixed name, changed interface to on-key-event
 ;; Fri Dec  9 21:39:03 EST 2005: remoevd (update ... produce ...); added on-redraw 
 ;; Thu Dec  1 17:03:03 EST 2005: fixed place-image; all coordinates okay now
@@ -11,13 +11,13 @@
    mred
    mzlib/class
    htdp/error
-   "image.ss"
+   "image.rkt"
    (prefix-in beg: lang/htdp-beginner)
    lang/prim
    deinprogramm/signature/signature-syntax)
   
   ;; --- provide ---------------------------------------------------------------
-  (provide (all-from-out "image.ss"))
+  (provide (all-from-out "image.rkt"))
   
   (provide      ;; forall(World):
    big-bang	;; Number Number Number World -> true 
diff --git a/collects/drracket/tool.rkt b/collects/drracket/tool.rkt
index 9d0842fc64..c30cdba52b 100644
--- a/collects/drracket/tool.rkt
+++ b/collects/drracket/tool.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-(require "private/drsig.ss")
+(require "private/drsig.rkt")
 (provide drracket:tool^
          drracket:tool-exports^
          drscheme:tool^
diff --git a/collects/dynext/compile-unit.rkt b/collects/dynext/compile-unit.rkt
index 3c2cff9454..c602b70eab 100644
--- a/collects/dynext/compile-unit.rkt
+++ b/collects/dynext/compile-unit.rkt
@@ -1,13 +1,12 @@
-
 (module compile-unit mzscheme
   (require mzlib/unit
-	   mzlib/process
-	   mzlib/sendevent
-	   "private/dirs.ss"
+           mzlib/process
+           mzlib/sendevent
+           "private/dirs.rkt"
            "private/stdio.rkt"
-	   "private/cmdargs.ss")
+           "private/cmdargs.rkt")
 
-  (require "compile-sig.ss")
+  (require "compile-sig.rkt")
 
   (provide dynext:compile@)
 
diff --git a/collects/dynext/compile.rkt b/collects/dynext/compile.rkt
index 3e3d98abad..8770b80aab 100644
--- a/collects/dynext/compile.rkt
+++ b/collects/dynext/compile.rkt
@@ -1,11 +1,9 @@
-
 (module compile mzscheme
   (require mzlib/unit)
 
-  (require "compile-sig.ss")
-  (require "compile-unit.ss")
+  (require "compile-sig.rkt"
+           "compile-unit.rkt")
 
   (define-values/invoke-unit/infer dynext:compile@)
 
   (provide-signature-elements dynext:compile^))
-
diff --git a/collects/dynext/dynext-sig.rkt b/collects/dynext/dynext-sig.rkt
index a5e4784fc9..4d21480f57 100644
--- a/collects/dynext/dynext-sig.rkt
+++ b/collects/dynext/dynext-sig.rkt
@@ -1,8 +1,7 @@
-
 (module dynext-sig mzscheme
 
-  (require "compile-sig.ss" "link-sig.ss" "file-sig.ss")
+  (require "compile-sig.rkt" "link-sig.rkt" "file-sig.rkt")
 
-  (provide (all-from "compile-sig.ss")
-	  (all-from "link-sig.ss")
-	  (all-from "file-sig.ss")))
+  (provide (all-from "compile-sig.rkt")
+           (all-from "link-sig.rkt")
+           (all-from "file-sig.rkt")))
diff --git a/collects/dynext/dynext-unit.rkt b/collects/dynext/dynext-unit.rkt
index 6a7d9f8a01..cc3185e9fb 100644
--- a/collects/dynext/dynext-unit.rkt
+++ b/collects/dynext/dynext-unit.rkt
@@ -1,8 +1,7 @@
-
 (module dynext-unit mzscheme
 
-  (require "compile-unit.ss" "link-unit.ss" "file-unit.ss")
+  (require "compile-unit.rkt" "link-unit.rkt" "file-unit.rkt")
 
-  (provide (all-from "compile-unit.ss")
-	  (all-from "link-unit.ss")
-	  (all-from "file-unit.ss")))
+  (provide (all-from "compile-unit.rkt")
+           (all-from "link-unit.rkt")
+           (all-from "file-unit.rkt")))
diff --git a/collects/dynext/dynext.rkt b/collects/dynext/dynext.rkt
index 71ece24c4d..a2650bf19f 100644
--- a/collects/dynext/dynext.rkt
+++ b/collects/dynext/dynext.rkt
@@ -1,8 +1,7 @@
-
 (module dynext mzscheme
 
-  (require "compile.ss" "link.ss" "file.ss")
+  (require "compile.rkt" "link.rkt" "file.rkt")
 
-  (provide (all-from "compile.ss")
-	  (all-from "link.ss")
-	  (all-from "file.ss")))
+  (provide (all-from "compile.rkt")
+           (all-from "link.rkt")
+           (all-from "file.rkt")))
diff --git a/collects/dynext/file-unit.rkt b/collects/dynext/file-unit.rkt
index b780401ccc..6ac7bb3c42 100644
--- a/collects/dynext/file-unit.rkt
+++ b/collects/dynext/file-unit.rkt
@@ -1,6 +1,6 @@
 #lang scheme/base
 
-(require scheme/unit "file-sig.ss")
+(require scheme/unit "file-sig.rkt")
 
 (provide dynext:file@)
 
diff --git a/collects/dynext/file.rkt b/collects/dynext/file.rkt
index a53092373f..ce1d1abd19 100644
--- a/collects/dynext/file.rkt
+++ b/collects/dynext/file.rkt
@@ -1,9 +1,8 @@
-
 (module file mzscheme
   (require mzlib/unit)
 
-  (require "file-sig.ss")
-  (require "file-unit.ss")
+  (require "file-sig.rkt"
+           "file-unit.rkt")
 
   (define-values/invoke-unit/infer dynext:file@)
 
diff --git a/collects/dynext/link-unit.rkt b/collects/dynext/link-unit.rkt
index e54bfe32ee..ba0a69a091 100644
--- a/collects/dynext/link-unit.rkt
+++ b/collects/dynext/link-unit.rkt
@@ -1,14 +1,13 @@
-
 (module link-unit mzscheme
   (require mzlib/unit
-	   mzlib/process
-	   mzlib/sendevent
-	   "private/dirs.ss"
+           mzlib/process
+           mzlib/sendevent
+           "private/dirs.rkt"
            "private/stdio.rkt"
-	   "private/cmdargs.ss"
-           "filename-version.ss")
+           "private/cmdargs.rkt"
+           "filename-version.rkt")
 
-  (require "link-sig.ss")
+  (require "link-sig.rkt")
 
   (provide dynext:link@)
 
diff --git a/collects/dynext/link.rkt b/collects/dynext/link.rkt
index 7fcced9567..c330b86a1e 100644
--- a/collects/dynext/link.rkt
+++ b/collects/dynext/link.rkt
@@ -1,9 +1,8 @@
-
 (module link mzscheme
   (require mzlib/unit)
 
-  (require "link-sig.ss")
-  (require "link-unit.ss")
+  (require "link-sig.rkt"
+           "link-unit.rkt")
 
   (define-values/invoke-unit/infer dynext:link@)
 
diff --git a/collects/dynext/main.rkt b/collects/dynext/main.rkt
index c7dcc193c9..f046f8200f 100644
--- a/collects/dynext/main.rkt
+++ b/collects/dynext/main.rkt
@@ -1,4 +1,4 @@
 #lang scheme/base
 
-(require "dynext.ss")
-(provide (all-from-out "dynext.ss"))
+(require "dynext.rkt")
+(provide (all-from-out "dynext.rkt"))
diff --git a/collects/embedded-gui/embedded-gui.rkt b/collects/embedded-gui/embedded-gui.rkt
index 5eab56a1a2..fd786a43e2 100644
--- a/collects/embedded-gui/embedded-gui.rkt
+++ b/collects/embedded-gui/embedded-gui.rkt
@@ -7,25 +7,25 @@
                (provide (all-from filename) ...))]))
   
   (require/provide
-   "private/interface.ss"
+   "private/interface.rkt"
    
-   "private/aligned-pasteboard.ss"
-   "private/verthoriz-alignment.ss"
-   "private/grid-alignment.ss"
-   "private/snip-wrapper.ss"
+   "private/aligned-pasteboard.rkt"
+   "private/verthoriz-alignment.rkt"
+   "private/grid-alignment.rkt"
+   "private/snip-wrapper.rkt"
    
-   "private/on-show-editor.ss"
+   "private/on-show-editor.rkt"
    
-   "private/button-snip.ss"
-   "private/embedded-message.ss"
-   "private/fixed-width-label-snip.ss"
-   "private/lines.ss"
+   "private/button-snip.rkt"
+   "private/embedded-message.rkt"
+   "private/fixed-width-label-snip.rkt"
+   "private/lines.rkt"
    
-   "private/stretchable-editor-snip.ss"
-   "private/tabbable-text.ss"
-   "private/grey-editor.ss"
-   "private/single-line-text.ss"
-   "private/cue-text.ss"
+   "private/stretchable-editor-snip.rkt"
+   "private/tabbable-text.rkt"
+   "private/grey-editor.rkt"
+   "private/single-line-text.rkt"
+   "private/cue-text.rkt"
    
-   "private/snip-lib.ss")
+   "private/snip-lib.rkt")
   )
diff --git a/collects/embedded-gui/main.rkt b/collects/embedded-gui/main.rkt
index 2e31f7bc1e..9aab7e8153 100644
--- a/collects/embedded-gui/main.rkt
+++ b/collects/embedded-gui/main.rkt
@@ -1,4 +1,4 @@
 #lang scheme/base
 
-(require "embedded-gui.ss")
-(provide (all-from-out "embedded-gui.ss"))
+(require "embedded-gui.rkt")
+(provide (all-from-out "embedded-gui.rkt"))
diff --git a/collects/embedded-gui/private/aligned-pasteboard.rkt b/collects/embedded-gui/private/aligned-pasteboard.rkt
index b742f88067..3d8ddd0227 100644
--- a/collects/embedded-gui/private/aligned-pasteboard.rkt
+++ b/collects/embedded-gui/private/aligned-pasteboard.rkt
@@ -13,12 +13,12 @@
    mred
    mzlib/etc
    mrlib/click-forwarding-editor
-   "on-show-pasteboard.ss"
-   "really-resized-pasteboard.ss"
-   "interface.ss"
-   "locked-pasteboard.ss"
-   "suppress-modify-editor.ss"
-   "on-show-editor.ss")
+   "on-show-pasteboard.rkt"
+   "really-resized-pasteboard.rkt"
+   "interface.rkt"
+   "locked-pasteboard.rkt"
+   "suppress-modify-editor.rkt"
+   "on-show-editor.rkt")
 
   (define aligned-pasteboard%
     (class* (click-forwarding-editor-mixin
diff --git a/collects/embedded-gui/private/alignment-helpers.rkt b/collects/embedded-gui/private/alignment-helpers.rkt
index e955ee21b3..4640880111 100644
--- a/collects/embedded-gui/private/alignment-helpers.rkt
+++ b/collects/embedded-gui/private/alignment-helpers.rkt
@@ -6,8 +6,8 @@
    mred
    mzlib/contract
    
-   "interface.ss"
-   "snip-lib.ss")
+   "interface.rkt"
+   "snip-lib.rkt")
   
   (provide/contract
    (vacuous-max (() (listof number?) . ->* . (number?)))
diff --git a/collects/embedded-gui/private/button-snip.rkt b/collects/embedded-gui/private/button-snip.rkt
index 45812d801f..064430c132 100644
--- a/collects/embedded-gui/private/button-snip.rkt
+++ b/collects/embedded-gui/private/button-snip.rkt
@@ -6,7 +6,7 @@
    mred
    mzlib/class
    mzlib/etc
-   "snip-wrapper.ss")
+   "snip-wrapper.rkt")
   
   (provide
    text-button-snip%
diff --git a/collects/embedded-gui/private/dllist.rkt b/collects/embedded-gui/private/dllist.rkt
index 52551158ab..a135c12e0c 100644
--- a/collects/embedded-gui/private/dllist.rkt
+++ b/collects/embedded-gui/private/dllist.rkt
@@ -5,7 +5,7 @@
    mzlib/list
    mzlib/etc
    framework
-   "interface.ss")
+   "interface.rkt")
   
   (provide dllist-mixin dllist% head% tail%)
   
diff --git a/collects/embedded-gui/private/embedded-message.rkt b/collects/embedded-gui/private/embedded-message.rkt
index 2f20456991..7645ba31cd 100644
--- a/collects/embedded-gui/private/embedded-message.rkt
+++ b/collects/embedded-gui/private/embedded-message.rkt
@@ -3,7 +3,7 @@
   (require
    mred
    mzlib/class
-   "snip-wrapper.ss")
+   "snip-wrapper.rkt")
   
   (provide embedded-message%)
 
diff --git a/collects/embedded-gui/private/grid-alignment.rkt b/collects/embedded-gui/private/grid-alignment.rkt
index 0dce40df64..c6b7b6eeb0 100644
--- a/collects/embedded-gui/private/grid-alignment.rkt
+++ b/collects/embedded-gui/private/grid-alignment.rkt
@@ -12,14 +12,14 @@
    mzlib/etc
    mzlib/list
    mzlib/match
-   (prefix a: "alignment.ss")
+   (prefix a: "alignment.rkt")
    mrlib/click-forwarding-editor
    
-   "on-show-pasteboard.ss"
-   "really-resized-pasteboard.ss"
-   "interface.ss"
-   "snip-lib.ss"
-   "alignment-helpers.ss")
+   "on-show-pasteboard.rkt"
+   "really-resized-pasteboard.rkt"
+   "interface.rkt"
+   "snip-lib.rkt"
+   "alignment-helpers.rkt")
   
   (provide grid-alignment%)
   
diff --git a/collects/embedded-gui/private/lines.rkt b/collects/embedded-gui/private/lines.rkt
index 5f24dafafb..0805be6eeb 100644
--- a/collects/embedded-gui/private/lines.rkt
+++ b/collects/embedded-gui/private/lines.rkt
@@ -4,8 +4,8 @@
    mzlib/class
    mzlib/etc
    mred
-   "snip-wrapper.ss"
-   "interface.ss")
+   "snip-wrapper.rkt"
+   "interface.rkt")
   
   (provide hline% vline%)
   
@@ -125,9 +125,9 @@
   
   #|
   (require
-   "verthoriz-alignment.ss"
-   "aligned-pasteboard.ss"
-   "snip-wrapper.ss")
+   "verthoriz-alignment.rkt"
+   "aligned-pasteboard.rkt"
+   "snip-wrapper.rkt")
   
   (define f (new frame% (label "f") (height 500) (width 500)))
   (send f show true)
diff --git a/collects/embedded-gui/private/on-show-editor.rkt b/collects/embedded-gui/private/on-show-editor.rkt
index 1b1c0820b7..f93d75b7d5 100644
--- a/collects/embedded-gui/private/on-show-editor.rkt
+++ b/collects/embedded-gui/private/on-show-editor.rkt
@@ -5,7 +5,7 @@
    mzlib/etc
    mred
    framework
-   "snip-lib.ss")
+   "snip-lib.rkt")
   
   (provide
    on-show-editor<%>
diff --git a/collects/embedded-gui/private/program-editor.rkt b/collects/embedded-gui/private/program-editor.rkt
index a9f67b8d0f..9b3be80cba 100644
--- a/collects/embedded-gui/private/program-editor.rkt
+++ b/collects/embedded-gui/private/program-editor.rkt
@@ -26,7 +26,7 @@ is being reset.
    mzlib/etc
    mzlib/class
    framework
-   "snip-lib.ss")
+   "snip-lib.rkt")
   
   (provide program-editor-mixin
            program-editor%)
diff --git a/collects/embedded-gui/private/snip-lib.rkt b/collects/embedded-gui/private/snip-lib.rkt
index fa01ce8f6e..0f7e055dc0 100644
--- a/collects/embedded-gui/private/snip-lib.rkt
+++ b/collects/embedded-gui/private/snip-lib.rkt
@@ -8,7 +8,7 @@
    mred
    mzlib/list
    mzlib/contract
-   "interface.ss")
+   "interface.rkt")
   
   ;; a snip
   (define snip? (is-a?/c snip%))
diff --git a/collects/embedded-gui/private/snip-wrapper.rkt b/collects/embedded-gui/private/snip-wrapper.rkt
index a52cfa6439..014a34ee14 100644
--- a/collects/embedded-gui/private/snip-wrapper.rkt
+++ b/collects/embedded-gui/private/snip-wrapper.rkt
@@ -4,9 +4,9 @@
    mzlib/etc
    mzlib/class
    mred
-   "interface.ss"
-   (prefix sl: "snip-lib.ss")
-   "dllist.ss")
+   "interface.rkt"
+   (prefix sl: "snip-lib.rkt")
+   "dllist.rkt")
   
   (provide control-style
 	   snip-wrapper%)
diff --git a/collects/embedded-gui/private/stretchable-editor-snip.rkt b/collects/embedded-gui/private/stretchable-editor-snip.rkt
index b295f50975..36301e3a5e 100644
--- a/collects/embedded-gui/private/stretchable-editor-snip.rkt
+++ b/collects/embedded-gui/private/stretchable-editor-snip.rkt
@@ -9,7 +9,7 @@
    mred
    mzlib/etc
    
-   "interface.ss")
+   "interface.rkt")
   
   (define (stretchable-editor-snip-mixin super%)
     (class* super% (stretchable-snip<%>)
diff --git a/collects/embedded-gui/private/tests/alignment-test.rkt b/collects/embedded-gui/private/tests/alignment-test.rkt
index fd9426182f..1609a68679 100644
--- a/collects/embedded-gui/private/tests/alignment-test.rkt
+++ b/collects/embedded-gui/private/tests/alignment-test.rkt
@@ -2,12 +2,12 @@
  mzlib/class
  mzlib/etc
  mred
- "../verthoriz-alignment.ss"
- "../lines.ss"
- "../aligned-pasteboard.ss"
- "../snip-wrapper.ss")
+ "../verthoriz-alignment.rkt"
+ "../lines.rkt"
+ "../aligned-pasteboard.rkt"
+ "../snip-wrapper.rkt")
 
-(require "../snip-lib.ss")
+(require "../snip-lib.rkt")
 
 (define f (new frame% (label "f") (height 500) (width 500)))
 (send f show true)
diff --git a/collects/embedded-gui/private/tests/only-one-child.rkt b/collects/embedded-gui/private/tests/only-one-child.rkt
index 260839bc90..898cc3b62a 100644
--- a/collects/embedded-gui/private/tests/only-one-child.rkt
+++ b/collects/embedded-gui/private/tests/only-one-child.rkt
@@ -4,15 +4,15 @@
  mzlib/etc
  mzlib/list
  mzlib/match
- (prefix a: "../alignment.ss")
- "../alignment-helpers.ss"
- "../dllist.ss"
+ (prefix a: "../alignment.rkt")
+ "../alignment-helpers.rkt"
+ "../dllist.rkt"
  mrlib/click-forwarding-editor
- "../on-show-pasteboard.ss"
- "../really-resized-pasteboard.ss"
- "../interface.ss"
- "../locked-pasteboard.ss"
- "../suppress-modify-editor.ss")
+ "../on-show-pasteboard.rkt"
+ "../really-resized-pasteboard.rkt"
+ "../interface.rkt"
+ "../locked-pasteboard.rkt"
+ "../suppress-modify-editor.rkt")
 
 ;;;;;;;;;;
 ;; alignment
diff --git a/collects/embedded-gui/private/tests/peer-stretchables.rkt b/collects/embedded-gui/private/tests/peer-stretchables.rkt
index 4d93273d0c..709015fd85 100644
--- a/collects/embedded-gui/private/tests/peer-stretchables.rkt
+++ b/collects/embedded-gui/private/tests/peer-stretchables.rkt
@@ -2,9 +2,9 @@
  mzlib/class
  mzlib/etc
  mred
- "../stretchable-editor-snip.ss"
- "../verthoriz-alignment.ss"
- "../aligned-pasteboard.ss")
+ "../stretchable-editor-snip.rkt"
+ "../verthoriz-alignment.rkt"
+ "../aligned-pasteboard.rkt")
 
 (define f (new frame% (label "f") (width 400) (height 400)))
 (define e (new text%))
diff --git a/collects/embedded-gui/private/tests/test-alignment.rkt b/collects/embedded-gui/private/tests/test-alignment.rkt
index b98132d1a2..d7857a013b 100644
--- a/collects/embedded-gui/private/tests/test-alignment.rkt
+++ b/collects/embedded-gui/private/tests/test-alignment.rkt
@@ -2,8 +2,8 @@
  mzlib/etc
  mzlib/list
  mzlib/match
- "../alignment.ss"
- "test-macro.ss")
+ "../alignment.rkt"
+ "test-macro.rkt")
 
 ;;los-equal? ((listof rect?) (listof rect?) . -> . boolean?)
 ;;tests the equality of the list of structures
diff --git a/collects/embedded-gui/private/tests/test-show-feature-for-test-case.rkt b/collects/embedded-gui/private/tests/test-show-feature-for-test-case.rkt
index f7eec39679..4805b1d30e 100644
--- a/collects/embedded-gui/private/tests/test-show-feature-for-test-case.rkt
+++ b/collects/embedded-gui/private/tests/test-show-feature-for-test-case.rkt
@@ -1,10 +1,10 @@
 (require
  mzlib/class
  mred
- "../aligned-pasteboard.ss"
- "../verthoriz-alignment.ss"
- "../snip-wrapper.ss"
- "../stretchable-editor-snip.ss")
+ "../aligned-pasteboard.rkt"
+ "../verthoriz-alignment.rkt"
+ "../snip-wrapper.rkt"
+ "../stretchable-editor-snip.rkt")
 
 (define actual-show? #f)
 (define collapsed? #t)
diff --git a/collects/embedded-gui/private/tests/test-show-feature.rkt b/collects/embedded-gui/private/tests/test-show-feature.rkt
index 44880cbc76..2e912ad14a 100644
--- a/collects/embedded-gui/private/tests/test-show-feature.rkt
+++ b/collects/embedded-gui/private/tests/test-show-feature.rkt
@@ -1,5 +1,5 @@
 #| This tests to make sure show works. It's not a correct test because
-   it's been abandoned and was reduced to wont-shrink.ss This is still
+   it's been abandoned and was reduced to wont-shrink.rkt This is still
    a good file for sandboxing show stuff though.
 |#
 
@@ -9,19 +9,19 @@
  mzlib/etc
  mzlib/list
  mzlib/match
- (prefix a: "../alignment.ss")
+ (prefix a: "../alignment.rkt")
    
- "../snip-lib.ss"
- "../interface.ss"
- "../alignment-helpers.ss"
+ "../snip-lib.rkt"
+ "../interface.rkt"
+ "../alignment-helpers.rkt"
  mrlib/click-forwarding-editor
- "../on-show-pasteboard.ss"
- "../really-resized-pasteboard.ss"
- "../interface.ss"
- "../snip-lib.ss"
- "../locked-pasteboard.ss"
- "../verthoriz-alignment.ss"
- "../suppress-modify-editor.ss")
+ "../on-show-pasteboard.rkt"
+ "../really-resized-pasteboard.rkt"
+ "../interface.rkt"
+ "../snip-lib.rkt"
+ "../locked-pasteboard.rkt"
+ "../verthoriz-alignment.rkt"
+ "../suppress-modify-editor.rkt")
   
 (require mike-lib/print-debug)
   
diff --git a/collects/embedded-gui/private/verthoriz-alignment.rkt b/collects/embedded-gui/private/verthoriz-alignment.rkt
index 145c732229..9a6ed2f01e 100644
--- a/collects/embedded-gui/private/verthoriz-alignment.rkt
+++ b/collects/embedded-gui/private/verthoriz-alignment.rkt
@@ -5,10 +5,10 @@
    mzlib/etc
    mzlib/list
    mzlib/match
-   (prefix a: "alignment.ss")
-   "interface.ss"
-   "alignment-helpers.ss"
-   "dllist.ss")
+   (prefix a: "alignment.rkt")
+   "interface.rkt"
+   "alignment-helpers.rkt"
+   "dllist.rkt")
    
   (provide
    horizontal-alignment%
diff --git a/collects/eopl/datatype.rkt b/collects/eopl/datatype.rkt
index 97c19d6f20..d39d08d817 100644
--- a/collects/eopl/datatype.rkt
+++ b/collects/eopl/datatype.rkt
@@ -4,7 +4,7 @@
 #lang mzscheme
 
 (require mzlib/pconvert-prop)
-(require-for-syntax "private/utils.ss")
+(require-for-syntax "private/utils.rkt")
 
 (define-syntax define-datatype
   (lambda (stx)
diff --git a/collects/eopl/eopl.rkt b/collects/eopl/eopl.rkt
index de4b3004a7..86da1df8d2 100644
--- a/collects/eopl/eopl.rkt
+++ b/collects/eopl/eopl.rkt
@@ -1,10 +1,10 @@
 #lang mzscheme
 
-(require "datatype.ss"
-         "private/sllgen.ss"
+(require "datatype.rkt"
+         "private/sllgen.rkt"
          mzlib/trace
          mzlib/pretty)
-(require-for-syntax "private/slldef.ss")
+(require-for-syntax "private/slldef.rkt")
 
 (provide define-datatype
          cases)
@@ -25,7 +25,7 @@
 
 (provide (rename eopl-define define))
 
-(provide (all-from "private/sllgen.ss"))
+(provide (all-from "private/sllgen.rkt"))
 
 (provide (rename error eopl:error)
          (rename printf eopl:printf)
diff --git a/collects/eopl/main.rkt b/collects/eopl/main.rkt
index db1b4368d1..eaac8af3fc 100644
--- a/collects/eopl/main.rkt
+++ b/collects/eopl/main.rkt
@@ -1,4 +1,4 @@
 #lang scheme/base
 
-(require "eopl.ss") ; provides `provide'
-(provide (all-from "eopl.ss"))
+(require "eopl.rkt") ; provides `provide'
+(provide (all-from "eopl.rkt"))
diff --git a/collects/eopl/private/sllgen.rkt b/collects/eopl/private/sllgen.rkt
index 8a089bb7f4..1934e26108 100644
--- a/collects/eopl/private/sllgen.rkt
+++ b/collects/eopl/private/sllgen.rkt
@@ -8,12 +8,12 @@
 (module sllgen mzscheme
   (require mzlib/pretty
            scheme/mpair
-	   "../datatype.ss"
-	   "sllboth.ss"
+	   "../datatype.rkt"
+	   "sllboth.rkt"
 	   mzlib/etc)
 
-  (require-for-syntax "sllboth.ss"
-		      "slldef.ss")
+  (require-for-syntax "sllboth.rkt"
+		      "slldef.rkt")
 
   (provide sllgen:make-string-scanner
 	   sllgen:make-string-parser
diff --git a/collects/ffi/cvector.rkt b/collects/ffi/cvector.rkt
index a22434e76f..8e53c8dfa8 100644
--- a/collects/ffi/cvector.rkt
+++ b/collects/ffi/cvector.rkt
@@ -1,7 +1,5 @@
 #lang racket/base
-(require "unsafe/cvector.ss")
+(require "unsafe/cvector.rkt")
 
-(provide (except-out (all-from-out "unsafe/cvector.ss")
+(provide (except-out (all-from-out "unsafe/cvector.rkt")
                      make-cvector*))
-
-
diff --git a/collects/ffi/examples/use-c-printf.rkt b/collects/ffi/examples/use-c-printf.rkt
index 39e9fb06d8..9a676fa05e 100755
--- a/collects/ffi/examples/use-c-printf.rkt
+++ b/collects/ffi/examples/use-c-printf.rkt
@@ -2,7 +2,7 @@
 
 #lang racket/base
 
-(require "c-printf.ss")
+(require "c-printf.rkt")
 
 (c-printf-is-dangerous!) ; see last example below
 
diff --git a/collects/ffi/examples/use-crypt.rkt b/collects/ffi/examples/use-crypt.rkt
index 4aeecf04d5..5e8ead5ca9 100755
--- a/collects/ffi/examples/use-crypt.rkt
+++ b/collects/ffi/examples/use-crypt.rkt
@@ -2,7 +2,7 @@
 
 #lang racket/base
 
-(require "crypt.ss")
+(require "crypt.rkt")
 
 (define passwd "foo")
 (define salt "xz")
diff --git a/collects/ffi/examples/use-esd.rkt b/collects/ffi/examples/use-esd.rkt
index 61a31fcf1d..cc2d0016a0 100755
--- a/collects/ffi/examples/use-esd.rkt
+++ b/collects/ffi/examples/use-esd.rkt
@@ -2,7 +2,7 @@
 
 #lang racket/base
 
-(require "esd.ss")
+(require "esd.rkt")
 
 (printf "default = ~s\n" (default-esd))
 (printf "latency = ~s\n" (esd-get-latency))
@@ -11,7 +11,7 @@
 (printf "resume  -> ~s\n" (esd-resume))
 
 (printf "Normal play...\n")
-(esd-play-file "esd.ss" "~/stuff/sounds/Eeeooop.wav" #t)
+(esd-play-file "esd.rkt" "~/stuff/sounds/Eeeooop.wav" #t)
 (sleep 1)
 
 (printf "Sample play...\n")
diff --git a/collects/ffi/examples/use-magick.rkt b/collects/ffi/examples/use-magick.rkt
index 4d943e90fe..dd1e6c9fd0 100755
--- a/collects/ffi/examples/use-magick.rkt
+++ b/collects/ffi/examples/use-magick.rkt
@@ -2,7 +2,7 @@
 
 #lang racket/base
 
-(require "magick.ss" (for-syntax racket/base))
+(require "magick.rkt" (for-syntax racket/base))
 
 (define-syntax (test stx)
   (syntax-case stx ()
diff --git a/collects/ffi/examples/use-sndfile.rkt b/collects/ffi/examples/use-sndfile.rkt
index 62c0c65744..e3dafa821c 100755
--- a/collects/ffi/examples/use-sndfile.rkt
+++ b/collects/ffi/examples/use-sndfile.rkt
@@ -2,7 +2,7 @@
 
 #lang racket/base
 
-(require "sndfile.ss")
+(require "sndfile.rkt")
 
 ;; (require swindle)
 
diff --git a/collects/ffi/examples/use-tcl.rkt b/collects/ffi/examples/use-tcl.rkt
index c163c8f95f..268e664478 100755
--- a/collects/ffi/examples/use-tcl.rkt
+++ b/collects/ffi/examples/use-tcl.rkt
@@ -2,7 +2,7 @@
 
 #lang racket/base
 
-(require "tcl.ss")
+(require "tcl.rkt")
 
 (define (tcldemo . strs)
   (for-each (lambda (s)
diff --git a/collects/ffi/examples/use-xmmsctrl.rkt b/collects/ffi/examples/use-xmmsctrl.rkt
index b83adbbf7b..548fa5ec07 100755
--- a/collects/ffi/examples/use-xmmsctrl.rkt
+++ b/collects/ffi/examples/use-xmmsctrl.rkt
@@ -2,7 +2,7 @@
 
 #lang racket/base
 
-(require (prefix-in xmms- "xmmsctrl.ss"))
+(require (prefix-in xmms- "xmmsctrl.rkt"))
 
 (printf "version: ~s\n" (xmms-get-version))
 (printf "skin: ~s\n" (xmms-get-skin))
diff --git a/collects/ffi/examples/use-xosd.rkt b/collects/ffi/examples/use-xosd.rkt
index bba6efc816..d757b7542c 100755
--- a/collects/ffi/examples/use-xosd.rkt
+++ b/collects/ffi/examples/use-xosd.rkt
@@ -2,7 +2,7 @@
 
 #lang racket/base
 
-(require "xosd.ss")
+(require "xosd.rkt")
 
 (define x (xosd-create))
 
diff --git a/collects/ffi/unsafe/alloc.rkt b/collects/ffi/unsafe/alloc.rkt
index 910f01fd0e..634667daed 100644
--- a/collects/ffi/unsafe/alloc.rkt
+++ b/collects/ffi/unsafe/alloc.rkt
@@ -1,6 +1,6 @@
 #lang racket/base
 (require ffi/unsafe
-         "atomic.ss")
+         "atomic.rkt")
 
 (provide allocator deallocator retainer 
          (rename-out [deallocator releaser]))
diff --git a/collects/ffi/unsafe/cvector.rkt b/collects/ffi/unsafe/cvector.rkt
index 1fc83d00f5..54c98f6c23 100644
--- a/collects/ffi/unsafe/cvector.rkt
+++ b/collects/ffi/unsafe/cvector.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-(require "../unsafe.ss")
+(require "../unsafe.rkt")
 
 (define-struct cvector (ptr type length))
 
diff --git a/collects/ffi/vector.rkt b/collects/ffi/vector.rkt
index 4728dee551..801319934b 100644
--- a/collects/ffi/vector.rkt
+++ b/collects/ffi/vector.rkt
@@ -1,6 +1,6 @@
 #lang racket/base
 
-(require "unsafe.ss"
+(require "unsafe.rkt"
          racket/unsafe/ops
          (for-syntax racket/base))
 
diff --git a/collects/file/tar.rkt b/collects/file/tar.rkt
index 4170ec8f45..0d18d8ee78 100644
--- a/collects/file/tar.rkt
+++ b/collects/file/tar.rkt
@@ -31,7 +31,7 @@
                (values (subbytes bts (add1 n)) (subbytes bts 0 n))]
               [else (loop (add1 n))])))))
 
-;; see also the same function name in zip.ss
+;; see also the same function name in "zip.rkt"
 (define (path-attributes path dir?)
   (apply bitwise-ior
          (map (lambda (p)
diff --git a/collects/framework/collapsed-snipclass.rkt b/collects/framework/collapsed-snipclass.rkt
index f2725335ea..a796d3ec59 100644
--- a/collects/framework/collapsed-snipclass.rkt
+++ b/collects/framework/collapsed-snipclass.rkt
@@ -1,7 +1,7 @@
 (module collapsed-snipclass mzscheme
   (require mred
            mzlib/class
-           "private/collapsed-snipclass-helpers.ss")
+           "private/collapsed-snipclass-helpers.rkt")
   
   (provide snip-class)
 
diff --git a/collects/framework/decorated-editor-snip.rkt b/collects/framework/decorated-editor-snip.rkt
index e1b75b2f2e..b8e68152dc 100644
--- a/collects/framework/decorated-editor-snip.rkt
+++ b/collects/framework/decorated-editor-snip.rkt
@@ -1,6 +1,6 @@
 #lang racket/base
 
-(require "private/decorated-editor-snip.ss")
+(require "private/decorated-editor-snip.rkt")
 
 (provide 
  (rename-out [editor-snip:decorated% decorated-editor-snip%])
diff --git a/collects/framework/framework-sig.rkt b/collects/framework/framework-sig.rkt
index 4d784ac614..905cfedabb 100644
--- a/collects/framework/framework-sig.rkt
+++ b/collects/framework/framework-sig.rkt
@@ -1,4 +1,3 @@
 #lang scheme/base
-(require "private/sig.ss")
+(require "private/sig.rkt")
 (provide framework^)
-
diff --git a/collects/framework/framework.rkt b/collects/framework/framework.rkt
index a2bbde30fb..5eb761974d 100644
--- a/collects/framework/framework.rkt
+++ b/collects/framework/framework.rkt
@@ -1,3 +1,3 @@
 #lang scheme/base
-(require "main.ss")
-(provide (all-from-out "main.ss"))
+(require "main.rkt")
+(provide (all-from-out "main.rkt"))
diff --git a/collects/framework/private/application.rkt b/collects/framework/private/application.rkt
index b777708261..250a633824 100644
--- a/collects/framework/private/application.rkt
+++ b/collects/framework/private/application.rkt
@@ -1,6 +1,6 @@
 #lang scheme/unit
 
-  (require "sig.ss")
+  (require "sig.rkt")
   
   (import)
   
diff --git a/collects/framework/private/autosave.rkt b/collects/framework/private/autosave.rkt
index aa2978c31e..3abd8e0169 100644
--- a/collects/framework/private/autosave.rkt
+++ b/collects/framework/private/autosave.rkt
@@ -2,9 +2,9 @@
 
   (require mzlib/class
            scheme/file
-           "sig.ss"
-           "../gui-utils.ss"
-           "../preferences.ss"
+           "sig.rkt"
+           "../gui-utils.rkt"
+           "../preferences.rkt"
            mred/mred-sig
            mzlib/list
            string-constants)
diff --git a/collects/framework/private/canvas.rkt b/collects/framework/private/canvas.rkt
index 666dd44cd4..6a62b4f3ec 100644
--- a/collects/framework/private/canvas.rkt
+++ b/collects/framework/private/canvas.rkt
@@ -1,7 +1,7 @@
 #lang scheme/unit
   (require mzlib/class
-           "sig.ss"
-           "../preferences.ss"
+           "sig.rkt"
+           "../preferences.rkt"
            mred/mred-sig)
   
   (import mred^
diff --git a/collects/framework/private/color-model.rkt b/collects/framework/private/color-model.rkt
index a18e015204..f3984d5628 100644
--- a/collects/framework/private/color-model.rkt
+++ b/collects/framework/private/color-model.rkt
@@ -1,6 +1,6 @@
 #lang scheme/unit
   (require mzlib/class
-           "sig.ss"
+           "sig.rkt"
            mred/mred-sig
            mzlib/list)
   
diff --git a/collects/framework/private/color-prefs.rkt b/collects/framework/private/color-prefs.rkt
index 6fdfa20360..bcb0017292 100644
--- a/collects/framework/private/color-prefs.rkt
+++ b/collects/framework/private/color-prefs.rkt
@@ -3,8 +3,8 @@
            mzlib/etc
            mred
            string-constants
-           "../preferences.ss"
-           "sig.ss")
+           "../preferences.rkt"
+           "sig.rkt")
   
   (import [prefix preferences: framework:preferences^]
           [prefix editor: framework:editor^]
diff --git a/collects/framework/private/color.rkt b/collects/framework/private/color.rkt
index d870d3c0f3..b850d9b69a 100644
--- a/collects/framework/private/color.rkt
+++ b/collects/framework/private/color.rkt
@@ -13,8 +13,8 @@ added get-regions
          syntax-color/paren-tree
          syntax-color/default-lexer
          string-constants
-         "../preferences.ss"
-         "sig.ss")
+         "../preferences.rkt"
+         "sig.rkt")
 
 (import [prefix icon: framework:icon^]
         [prefix mode: framework:mode^]
diff --git a/collects/framework/private/comment-box.rkt b/collects/framework/private/comment-box.rkt
index ce73ab0f7f..3d72e0c181 100644
--- a/collects/framework/private/comment-box.rkt
+++ b/collects/framework/private/comment-box.rkt
@@ -5,8 +5,8 @@
          scheme/class
          scheme/gui/base
          scheme/runtime-path
-         "sig.ss"
-         "../decorated-editor-snip.ss"
+         "sig.rkt"
+         "../decorated-editor-snip.rkt"
          string-constants)
 
 (define-runtime-path semicolon-bitmap-path '(lib "icons/semicolon.gif"))
diff --git a/collects/framework/private/decorated-editor-snip.rkt b/collects/framework/private/decorated-editor-snip.rkt
index 81df2cf211..f7c548a430 100644
--- a/collects/framework/private/decorated-editor-snip.rkt
+++ b/collects/framework/private/decorated-editor-snip.rkt
@@ -9,7 +9,7 @@
          editor-snip:decorated-mixin
          editor-snip:decorated<%>)
 
-(require "../preferences.ss")
+(require "../preferences.rkt")
 
 (define editor-snip:decorated<%>
   (interface ((class->interface editor-snip%))
diff --git a/collects/framework/private/early-init.rkt b/collects/framework/private/early-init.rkt
index 2dd7e459d8..56d3d0966c 100644
--- a/collects/framework/private/early-init.rkt
+++ b/collects/framework/private/early-init.rkt
@@ -1,6 +1,6 @@
 #lang racket/unit
 (require "sig.rkt"
-         "../preferences.ss")
+         "../preferences.rkt")
 (import [prefix preferences: framework:preferences^])
 (export framework:early-init^)
 (init-depend framework:preferences^)
diff --git a/collects/framework/private/editor.rkt b/collects/framework/private/editor.rkt
index 42c8e04397..661e4f4178 100644
--- a/collects/framework/private/editor.rkt
+++ b/collects/framework/private/editor.rkt
@@ -2,9 +2,9 @@
 
   (require mzlib/class
            string-constants
-           "sig.ss"
-           "../preferences.ss"
-           "../gui-utils.ss"
+           "sig.rkt"
+           "../preferences.rkt"
+           "../gui-utils.rkt"
            mzlib/etc
            mred/mred-sig
            scheme/path)
diff --git a/collects/framework/private/exit.rkt b/collects/framework/private/exit.rkt
index 1ff3f08fd1..1cb98c5db8 100644
--- a/collects/framework/private/exit.rkt
+++ b/collects/framework/private/exit.rkt
@@ -1,9 +1,9 @@
 #lang scheme/unit
 
   (require string-constants
-           "sig.ss"
-           "../preferences.ss"
-           "../gui-utils.ss"
+           "sig.rkt"
+           "../preferences.rkt"
+           "../gui-utils.rkt"
            mred/mred-sig)
   
   (import mred^)
diff --git a/collects/framework/private/finder.rkt b/collects/framework/private/finder.rkt
index 5136537f57..b2f60e0cf2 100644
--- a/collects/framework/private/finder.rkt
+++ b/collects/framework/private/finder.rkt
@@ -1,8 +1,8 @@
 #lang scheme/unit
 
   (require string-constants
-           "sig.ss"
-           "../preferences.ss"
+           "sig.rkt"
+           "../preferences.rkt"
            mred/mred-sig
            scheme/path)
   
diff --git a/collects/framework/private/frame.rkt b/collects/framework/private/frame.rkt
index 9b7ede9231..e10aabd00a 100644
--- a/collects/framework/private/frame.rkt
+++ b/collects/framework/private/frame.rkt
@@ -3,11 +3,11 @@
 (require string-constants
          scheme/class
          mzlib/include
-         "search.ss"
-         "sig.ss"
-         "../preferences.ss"
-         "../gui-utils.ss"
-         "bday.ss"
+         "search.rkt"
+         "sig.rkt"
+         "../preferences.rkt"
+         "../gui-utils.rkt"
+         "bday.rkt"
          mrlib/close-icon
          mred/mred-sig
          scheme/path)
diff --git a/collects/framework/private/gen-standard-menus.rkt b/collects/framework/private/gen-standard-menus.rkt
index 86fd7df41e..d680952894 100644
--- a/collects/framework/private/gen-standard-menus.rkt
+++ b/collects/framework/private/gen-standard-menus.rkt
@@ -3,12 +3,12 @@
 (provide main)
 (require scheme/pretty
          scheme/runtime-path)
-(require "standard-menus-items.ss")
+(require "standard-menus-items.rkt")
 
 (define-runtime-path here ".")
 
 (define standard-menus.rkt-filename (simplify-path (build-path here "standard-menus.rkt")))
-(define docs-menus.ss-filename (simplify-path (build-path here 'up 'up "scribblings" "framework" "standard-menus.scrbl")))
+(define docs-menus-filename (simplify-path (build-path here 'up 'up "scribblings" "framework" "standard-menus.scrbl")))
 
 ;; build-before-super-item-clause : an-item -> (listof clause)
 (define build-before-super-item-clause
@@ -125,8 +125,8 @@
   (write-docs))
 
 (define (write-docs)
-  (printf "writing to ~a\n" docs-menus.ss-filename)
-  (call-with-output-file docs-menus.ss-filename
+  (printf "writing to ~a\n" docs-menus-filename)
+  (call-with-output-file docs-menus-filename
     (λ (port)
       (define (pop-out sexp)
         (display "@" port)
diff --git a/collects/framework/private/group.rkt b/collects/framework/private/group.rkt
index 97bb30575f..1f9390a273 100644
--- a/collects/framework/private/group.rkt
+++ b/collects/framework/private/group.rkt
@@ -2,9 +2,9 @@
 
   (require string-constants
            mzlib/class
-           "sig.ss"
-           "../preferences.ss"
-           "../gui-utils.ss"
+           "sig.rkt"
+           "../preferences.rkt"
+           "../gui-utils.rkt"
            mred/mred-sig
            mzlib/list
            scheme/path)
diff --git a/collects/framework/private/handler.rkt b/collects/framework/private/handler.rkt
index 74aeb94d03..12aab4c698 100644
--- a/collects/framework/private/handler.rkt
+++ b/collects/framework/private/handler.rkt
@@ -3,9 +3,9 @@
 (require mzlib/class
          mzlib/list
          mrlib/hierlist
-         "sig.ss"
-         "../preferences.ss"
-         "../gui-utils.ss"
+         "sig.rkt"
+         "../preferences.rkt"
+         "../gui-utils.rkt"
          mred/mred-sig
          scheme/path
          string-constants)
diff --git a/collects/framework/private/icon.rkt b/collects/framework/private/icon.rkt
index 587ebea618..6eab849ece 100644
--- a/collects/framework/private/icon.rkt
+++ b/collects/framework/private/icon.rkt
@@ -5,8 +5,8 @@
          scheme/promise
          scheme/class
          scheme/runtime-path
-         "bday.ss"
-         "sig.ss"
+         "bday.rkt"
+         "sig.rkt"
          mred/mred-sig)
 
 (provide icon@)
diff --git a/collects/framework/private/keymap.rkt b/collects/framework/private/keymap.rkt
index 5319d82adf..d6db3db426 100644
--- a/collects/framework/private/keymap.rkt
+++ b/collects/framework/private/keymap.rkt
@@ -5,10 +5,10 @@
          mzlib/list
          mred/mred-sig
          mzlib/match
-         "../preferences.ss"
+         "../preferences.rkt"
          mrlib/tex-table
          (only-in srfi/13 string-prefix? string-prefix-length)
-         "sig.ss")
+         "sig.rkt")
 
   (import mred^
           [prefix finder: framework:finder^]
@@ -51,7 +51,9 @@
   (define (valid-keybindings-lang? x)
     (member x
             (list `(lib "keybinding-lang.ss" "framework")
+                  `(lib "keybinding-lang.rkt" "framework")
                   `(lib "framework/keybinding-lang.ss")
+                  `(lib "framework/keybinding-lang.rkt")
                   `framework/keybinding-lang)))
   
   (define (spec->path p)
@@ -1454,7 +1456,7 @@
                     (case (system-type)
                       [(macosx macos) "d:"]
                       [(windows unix) "c:"]
-                      [else (error 'keymap.ss "unknown platform: ~s" (system-type))])
+                      [else (error 'keymap.rkt "unknown platform: ~s" (system-type))])
                     key)
                    func))])
       (add/map "editor-undo" 'undo "z")
diff --git a/collects/framework/private/main.rkt b/collects/framework/private/main.rkt
index 3227e9379b..d29864552f 100644
--- a/collects/framework/private/main.rkt
+++ b/collects/framework/private/main.rkt
@@ -1,7 +1,7 @@
 #lang racket/unit
 (require racket/class
-         "sig.ss"
-         "../preferences.ss"
+         "sig.rkt"
+         "../preferences.rkt"
          mred/mred-sig)
 
 (import mred^
diff --git a/collects/framework/private/menu.rkt b/collects/framework/private/menu.rkt
index 81eab518aa..d50568d210 100644
--- a/collects/framework/private/menu.rkt
+++ b/collects/framework/private/menu.rkt
@@ -1,7 +1,7 @@
 #lang scheme/unit
   (require mzlib/class
-           "sig.ss"
-           "../preferences.ss"
+           "sig.rkt"
+           "../preferences.rkt"
            mred/mred-sig)
   
   (import mred^)
diff --git a/collects/framework/private/mode.rkt b/collects/framework/private/mode.rkt
index 416caf6dcb..ab27f14e8f 100644
--- a/collects/framework/private/mode.rkt
+++ b/collects/framework/private/mode.rkt
@@ -4,7 +4,7 @@
          scheme/unit
          scheme/class
          scheme/surrogate
-         "sig.ss")
+         "sig.rkt")
 
 (provide mode@ surrogate-methods)
 
diff --git a/collects/framework/private/number-snip.rkt b/collects/framework/private/number-snip.rkt
index 6b0296f815..52811c3da1 100644
--- a/collects/framework/private/number-snip.rkt
+++ b/collects/framework/private/number-snip.rkt
@@ -1,9 +1,9 @@
 #lang racket/unit
 
-  (require "sig.ss"
+  (require "sig.rkt"
            mred/mred-sig
            racket/class
-           "../preferences.ss"
+           "../preferences.rkt"
            string-constants)
   
   (import mred^)
diff --git a/collects/framework/private/panel.rkt b/collects/framework/private/panel.rkt
index 5377b8088b..fa713bf5ab 100644
--- a/collects/framework/private/panel.rkt
+++ b/collects/framework/private/panel.rkt
@@ -1,7 +1,7 @@
 #lang racket/unit
 
   (require mzlib/class
-           "sig.ss"
+           "sig.rkt"
            mred/mred-sig
            mzlib/list
            mzlib/etc)
diff --git a/collects/framework/private/pasteboard.rkt b/collects/framework/private/pasteboard.rkt
index cfd8a0c412..d8b59f6d59 100644
--- a/collects/framework/private/pasteboard.rkt
+++ b/collects/framework/private/pasteboard.rkt
@@ -1,5 +1,5 @@
 #lang scheme/unit
-  (require "sig.ss" mred/mred-sig)
+  (require "sig.rkt" mred/mred-sig)
 
   (import mred^
           [prefix editor: framework:editor^])
diff --git a/collects/framework/private/path-utils.rkt b/collects/framework/private/path-utils.rkt
index 72810d5be0..ff348906a3 100644
--- a/collects/framework/private/path-utils.rkt
+++ b/collects/framework/private/path-utils.rkt
@@ -1,5 +1,5 @@
 #lang scheme/unit
-  (require "sig.ss" mred/mred-sig)
+  (require "sig.rkt" mred/mred-sig)
   
   (import)
   (export framework:path-utils^)
diff --git a/collects/framework/private/preferences.rkt b/collects/framework/private/preferences.rkt
index 671e3ba339..c8077342ea 100644
--- a/collects/framework/private/preferences.rkt
+++ b/collects/framework/private/preferences.rkt
@@ -31,9 +31,9 @@ the state transitions / contracts are:
   (require string-constants
 	   mzlib/class
            racket/file
-           "sig.ss"
-           "../gui-utils.ss"
-           "../preferences.ss"
+           "sig.rkt"
+           "../gui-utils.rkt"
+           "../preferences.rkt"
 	   mred/mred-sig
 	   mzlib/list)
   
diff --git a/collects/framework/private/scheme.rkt b/collects/framework/private/scheme.rkt
index 712d03756e..a5ad3f8286 100644
--- a/collects/framework/private/scheme.rkt
+++ b/collects/framework/private/scheme.rkt
@@ -7,10 +7,10 @@
          scheme/class
          mred/mred-sig
          syntax-color/module-lexer
-         "collapsed-snipclass-helpers.ss"
-         "sig.ss"
-         "../gui-utils.ss"
-         "../preferences.ss"
+         "collapsed-snipclass-helpers.rkt"
+         "sig.rkt"
+         "../gui-utils.rkt"
+         "../preferences.rkt"
          scheme/match)
 
 (import mred^
diff --git a/collects/framework/private/version.rkt b/collects/framework/private/version.rkt
index 1ef687c83c..8ae9e2b0d2 100644
--- a/collects/framework/private/version.rkt
+++ b/collects/framework/private/version.rkt
@@ -1,6 +1,6 @@
 #lang scheme/unit
 
-  (require "sig.ss"
+  (require "sig.rkt"
            mred/mred-sig
            mzlib/string
            mzlib/list)
diff --git a/collects/frtime/animation/graphics-posn-less-unit.rkt b/collects/frtime/animation/graphics-posn-less-unit.rkt
index e59e98e244..96368c7a7c 100644
--- a/collects/frtime/animation/graphics-posn-less-unit.rkt
+++ b/collects/frtime/animation/graphics-posn-less-unit.rkt
@@ -1,4 +1,3 @@
-; graphics.ss
 ; Simple graphics routines for GRacket
 ; Originally written by Johnathan Franklin
 ;
@@ -11,7 +10,7 @@
 	   mzlib/class100
 	   mzlib/etc
            frtime/core/frp
-	   "graphics-sig.ss")
+	   "graphics-sig.rkt")
 
   (import (prefix mred: mred^)
           graphics:posn^)
diff --git a/collects/frtime/animation/graphics-unit.rkt b/collects/frtime/animation/graphics-unit.rkt
index d3e23563a9..7c6a0e4e09 100644
--- a/collects/frtime/animation/graphics-unit.rkt
+++ b/collects/frtime/animation/graphics-unit.rkt
@@ -1,8 +1,8 @@
 #lang scheme
 (require scheme/unit
          mred/mred-sig
-         "graphics-sig.ss"
-         "graphics-posn-less-unit.ss")
+         "graphics-sig.rkt"
+         "graphics-posn-less-unit.rkt")
 (provide graphics@)
 
 (define-unit posn@ (import) (export graphics:posn^)
diff --git a/collects/frtime/animation/graphics.rkt b/collects/frtime/animation/graphics.rkt
index f169c6ffbd..82a18ee48a 100644
--- a/collects/frtime/animation/graphics.rkt
+++ b/collects/frtime/animation/graphics.rkt
@@ -2,8 +2,8 @@
 (require scheme/unit
          mred/mred-sig
          mred
-         "graphics-sig.ss"
-         "graphics-unit.ss")
+         "graphics-sig.rkt"
+         "graphics-unit.rkt")
 (provide-signature-elements graphics:posn^ graphics:posn-less^)
 
 (define-values/invoke-unit/infer graphics@)
diff --git a/collects/frtime/core/dv.rkt b/collects/frtime/core/dv.rkt
index fdc2d403a9..d61cd7140f 100644
--- a/collects/frtime/core/dv.rkt
+++ b/collects/frtime/core/dv.rkt
@@ -1,5 +1,5 @@
 #lang scheme
-(require "contract.ss")
+(require "contract.rkt")
 
 (define-struct dv (vec-length next-avail-pos vec) #:mutable)
 
diff --git a/collects/frtime/core/erl.rkt b/collects/frtime/core/erl.rkt
index 6e25327fda..726a161e62 100644
--- a/collects/frtime/core/erl.rkt
+++ b/collects/frtime/core/erl.rkt
@@ -1,8 +1,8 @@
 #lang scheme
-(require "match.ss"
-         "contract.ss"
-         #;"sema-mailbox.ss"
-         "mailbox.ss")
+(require "match.rkt"
+         "contract.rkt"
+         #;"sema-mailbox.rkt"
+         "mailbox.rkt")
 
 (define-struct tid (lid) #:prefab)
 (define (create-tid thr) (make-tid thr))
diff --git a/collects/frtime/core/frp.rkt b/collects/frtime/core/frp.rkt
index 24f427426b..3e1986d751 100644
--- a/collects/frtime/core/frp.rkt
+++ b/collects/frtime/core/frp.rkt
@@ -1,9 +1,9 @@
 #lang scheme
 (require (only-in mzlib/etc 
                   identity nor)
-         "contract.ss"
-         "erl.ss"
-         "heap.ss")
+         "contract.rkt"
+         "erl.rkt"
+         "heap.rkt")
 
 ;;;;;;;;;;;;;
 ;; Globals ;;
diff --git a/collects/frtime/core/heap.rkt b/collects/frtime/core/heap.rkt
index ee7b9b1853..4559867687 100644
--- a/collects/frtime/core/heap.rkt
+++ b/collects/frtime/core/heap.rkt
@@ -1,6 +1,6 @@
 #lang scheme
-(require "dv.ss"
-         "contract.ss")
+(require "dv.rkt"
+         "contract.rkt")
 
 (define-struct t (sorter equality data))
 
diff --git a/collects/frtime/core/mailbox.rkt b/collects/frtime/core/mailbox.rkt
index 14026afe22..17438d3353 100644
--- a/collects/frtime/core/mailbox.rkt
+++ b/collects/frtime/core/mailbox.rkt
@@ -1,6 +1,6 @@
 #lang scheme
-(require "contract.ss"
-         "match.ss"
+(require "contract.rkt"
+         "match.rkt"
          scheme/async-channel)
 
 ; XXX More efficient structure
diff --git a/collects/frtime/core/sema-mailbox.rkt b/collects/frtime/core/sema-mailbox.rkt
index a39603b693..a97639af8d 100644
--- a/collects/frtime/core/sema-mailbox.rkt
+++ b/collects/frtime/core/sema-mailbox.rkt
@@ -1,6 +1,6 @@
 #lang scheme
-(require "match.ss"
-         "contract.ss")
+(require "match.rkt"
+         "contract.rkt")
 
 (define (call-with-semaphore s thunk)
     (semaphore-wait s)
diff --git a/collects/frtime/frlibs/date.rkt b/collects/frtime/frlibs/date.rkt
index 86dfd58920..ac7048e86e 100644
--- a/collects/frtime/frlibs/date.rkt
+++ b/collects/frtime/frlibs/date.rkt
@@ -1,5 +1,5 @@
 #lang scheme
-(require "list.ss")
+(require "list.rkt")
 (require (rename-in (only-in frtime/frtime provide)
                     [provide frtime:provide]))
 
diff --git a/collects/frtime/frlibs/math.rkt b/collects/frtime/frlibs/math.rkt
index 82b3a92627..96d8ad6a72 100644
--- a/collects/frtime/frlibs/math.rkt
+++ b/collects/frtime/frlibs/math.rkt
@@ -1,6 +1,6 @@
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;
-;; math.ss: some extra math routines
+;; math.rkt: some extra math routines
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 (module math frtime/frtime-lang-only
diff --git a/collects/frtime/frtime-lang-only.rkt b/collects/frtime/frtime-lang-only.rkt
index 87838e979f..5161d0a5c6 100644
--- a/collects/frtime/frtime-lang-only.rkt
+++ b/collects/frtime/frtime-lang-only.rkt
@@ -1,4 +1,4 @@
-(module frtime-lang-only "lang-utils.ss"
+(module frtime-lang-only "lang-utils.rkt"
   (require frtime/lang-ext)
   (require (as-is:unchecked frtime/core/frp
 	    event-set? signal-value))
@@ -13,5 +13,5 @@
           (pred v))))
 
   (provide value-nowable? behaviorof
-	   (all-from "lang-utils.ss")
+	   (all-from "lang-utils.rkt")
            (all-from-except frtime/lang-ext lift)))
diff --git a/collects/frtime/frtime.rkt b/collects/frtime/frtime.rkt
index c9e5aa2bfd..802e5b8fef 100644
--- a/collects/frtime/frtime.rkt
+++ b/collects/frtime/frtime.rkt
@@ -1,6 +1,6 @@
-(module frtime "lang-utils.ss"
-  (require (all-except "lang-ext.ss" lift deep-value-now))
-  (require "frp-snip.ss")
+(module frtime "lang-utils.rkt"
+  (require (all-except "lang-ext.rkt" lift deep-value-now))
+  (require "frp-snip.rkt")
   (require (as-is:unchecked frtime/core/frp
                             event-set? signal-value))
 
@@ -14,6 +14,6 @@
           (pred v))))
 
   (provide value-nowable? behaviorof
-           (all-from "lang-ext.ss")
-	   (all-from "lang-utils.ss")
-           (all-from "frp-snip.ss")))
+           (all-from "lang-ext.rkt")
+	   (all-from "lang-utils.rkt")
+           (all-from "frp-snip.rkt")))
diff --git a/collects/frtime/gui/aux-mixin-macros.rkt b/collects/frtime/gui/aux-mixin-macros.rkt
index 64d419da01..8a84b550d9 100644
--- a/collects/frtime/gui/aux-mixin-macros.rkt
+++ b/collects/frtime/gui/aux-mixin-macros.rkt
@@ -1,5 +1,5 @@
 (module aux-mixin-macros frtime
-  (require "mixin-macros.ss")
+  (require "mixin-macros.rkt")
   (require mzlib/class)
 
   
diff --git a/collects/frtime/gui/demo/instr.rkt b/collects/frtime/gui/demo/instr.rkt
index 76bf3c9720..c015cd3c2c 100644
--- a/collects/frtime/gui/demo/instr.rkt
+++ b/collects/frtime/gui/demo/instr.rkt
@@ -5,7 +5,7 @@
 
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;
-;; behavior->callbacks ;; (aux-mixin-macros.ss)
+;; behavior->callbacks ;; (aux-mixin-macros.rkt)
 ;;;;;;;;;;;;;;;;;;;;;;;;;
 
 ; create a mixin using the macro
@@ -27,7 +27,7 @@
 
 
 ;;;;;;;;;;;;;;;;;;;;;;;
-;; events->callbacks ;; (mixin-macros.ss)
+;; events->callbacks ;; (mixin-macros.rkt)
 ;;;;;;;;;;;;;;;;;;;;;;;
 
 ; create a mixin using the macro
@@ -55,7 +55,7 @@
 
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;
-;; callbacks->args-evts ;; (mixin-macros.ss)
+;; callbacks->args-evts ;; (mixin-macros.rkt)
 ;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 ; create a mixin using the macro
@@ -102,7 +102,7 @@
 
 
 ;;;;;;;;;;;;;;;;;;;
-;; mixin-merge-e ;; (aux-mixin-macros.ss)
+;; mixin-merge-e ;; (aux-mixin-macros.rkt)
 ;;;;;;;;;;;;;;;;;;;
 
 
diff --git a/collects/frtime/gui/fred.rkt b/collects/frtime/gui/fred.rkt
index 09e539c2b7..9628f29439 100644
--- a/collects/frtime/gui/fred.rkt
+++ b/collects/frtime/gui/fred.rkt
@@ -1,6 +1,6 @@
 (module fred frtime
-  (require "mixin-macros.ss"
-           "aux-mixin-macros.ss"
+  (require "mixin-macros.rkt"
+           "aux-mixin-macros.rkt"
            mzlib/class
            mzlib/string
            texpict/mrpict
@@ -324,8 +324,5 @@
   
   (provide (all-defined)
            (all-from mzlib/class)
-           (all-from "mixin-macros.ss")
-           (all-from "aux-mixin-macros.ss"))) 
-
-
-
+           (all-from "mixin-macros.rkt")
+           (all-from "aux-mixin-macros.rkt")))
diff --git a/collects/frtime/gui/simple.rkt b/collects/frtime/gui/simple.rkt
index 9de850342f..20c4b8c1d4 100644
--- a/collects/frtime/gui/simple.rkt
+++ b/collects/frtime/gui/simple.rkt
@@ -1,6 +1,6 @@
 (module simple frtime
   
-  (require "fred.ss"
+  (require "fred.rkt"
            mzlib/class
            (rename mred frame% frame%))
   
@@ -49,5 +49,5 @@
 
   
   (provide (all-defined)
-           (all-from "fred.ss")
+           (all-from "fred.rkt")
            (all-from mzlib/class)))
diff --git a/collects/frtime/lang-utils.rkt b/collects/frtime/lang-utils.rkt
index c4c918d966..359f1817fa 100644
--- a/collects/frtime/lang-utils.rkt
+++ b/collects/frtime/lang-utils.rkt
@@ -1,4 +1,4 @@
-(module lang-utils "lang-core.ss"
+(module lang-utils "lang-core.rkt"
   
   (require (all-except mzscheme
                        module
@@ -33,10 +33,10 @@
                        cond when unless
                        map ormap andmap assoc member)
            (rename mzscheme mzscheme:if if)
-           (rename "lang-ext.ss" lift lift)
+           (rename "lang-ext.rkt" lift lift)
            (only frtime/core/frp super-lift behavior? value-now)
-           (rename "lang-ext.ss" undefined undefined)
-           (rename "lang-ext.ss" undefined? undefined?)
+           (rename "lang-ext.rkt" undefined undefined)
+           (rename "lang-ext.rkt" undefined? undefined?)
 	   mzlib/class)
   (require mzlib/list)
   
@@ -380,6 +380,6 @@
            )
   
   ; from core
-  (provide (all-from "lang-core.ss"))
-           
+  (provide (all-from "lang-core.rkt"))
+
   )
diff --git a/collects/frtime/main.rkt b/collects/frtime/main.rkt
index 53d7938252..4bbc7c022d 100644
--- a/collects/frtime/main.rkt
+++ b/collects/frtime/main.rkt
@@ -1,2 +1,2 @@
-(module main "frtime-big.ss"
-  (provide (all-from "frtime-big.ss")))
+(module main "frtime-big.rkt"
+  (provide (all-from "frtime-big.rkt")))
diff --git a/collects/frtime/opt/frtime-opt-lang.rkt b/collects/frtime/opt/frtime-opt-lang.rkt
index fd6286ef52..2ea9af9b66 100644
--- a/collects/frtime/opt/frtime-opt-lang.rkt
+++ b/collects/frtime/opt/frtime-opt-lang.rkt
@@ -29,7 +29,7 @@
                   ;; equiv doesn't become part of the module's namespace, and there's
                   ;; no way to find the list of identifiers exported by a module other
                   ;; than by filtering its namespace (see all-provided-symbols in 
-                  ;; lowered-equivs.ss)
+                  ;; lowered-equivs.rkt)
                   (define #,lowered-equiv-id FUNC)
                   (provide FUNC)
                   (provide #,lowered-equiv-id)))]
diff --git a/collects/frtime/reactive.rkt b/collects/frtime/reactive.rkt
index 614f85fa40..0763176d12 100644
--- a/collects/frtime/reactive.rkt
+++ b/collects/frtime/reactive.rkt
@@ -1,6 +1,6 @@
 (module reactive frtime/lang-utils
-  (require "lang-ext.ss"
-           "frp-snip.ss"
+  (require "lang-ext.rkt"
+           "frp-snip.rkt"
            frtime/frlibs/list
            frtime/frlibs/etc
            (as-is:unchecked frtime/core/frp
@@ -21,5 +21,5 @@
            (all-from frtime/frlibs/list)
            (all-from frtime/frlibs/etc)
            (all-from frtime/lang-utils)
-           (all-from-except "lang-ext.ss" lift)
-           (all-from "frp-snip.ss")))
+           (all-from-except "lang-ext.rkt" lift)
+           (all-from "frp-snip.rkt")))
diff --git a/collects/frtime/tool/info.rkt b/collects/frtime/tool/info.rkt
index c13137f7fa..6066a332de 100644
--- a/collects/frtime/tool/info.rkt
+++ b/collects/frtime/tool/info.rkt
@@ -1,6 +1,6 @@
 #lang setup/infotab
 (define name "FrTime Tool")
 
-(define tools      '("frtime-tool.ss"))
+(define tools      '("frtime-tool.rkt"))
 (define tool-icons '("clock.png"))
 (define tool-names '("FrTime Language"))
diff --git a/collects/games/blackjack/info.rkt b/collects/games/blackjack/info.rkt
index 3de489a479..20756cff3e 100644
--- a/collects/games/blackjack/info.rkt
+++ b/collects/games/blackjack/info.rkt
@@ -1,4 +1,4 @@
 #lang setup/infotab
 
-(define game "blackjack.ss")
+(define game "blackjack.rkt")
 (define game-set "Card Games")
diff --git a/collects/games/cards.rkt b/collects/games/cards.rkt
index 19d45cf456..bcc93e499d 100644
--- a/collects/games/cards.rkt
+++ b/collects/games/cards.rkt
@@ -1,4 +1,4 @@
 #lang mzscheme
 
-(require "cards/cards.ss")
-(provide (all-from "cards/cards.ss"))
+(require "cards/cards.rkt")
+(provide (all-from "cards/cards.rkt"))
diff --git a/collects/games/cards/base.rkt b/collects/games/cards/base.rkt
index 9419f07871..c8b707a023 100644
--- a/collects/games/cards/base.rkt
+++ b/collects/games/cards/base.rkt
@@ -1,6 +1,6 @@
-
 (module base mzscheme
-  (require mzlib/class mzlib/etc "make-cards.ss" "classes.ss" "card-class.ss")
+  (require mzlib/class mzlib/etc
+           "make-cards.rkt" "classes.rkt" "card-class.rkt")
 
   (provide make-table make-deck make-card
            table<%> card<%>)
diff --git a/collects/games/cards/card-class.rkt b/collects/games/cards/card-class.rkt
index 8424f726bf..4bf57f0841 100644
--- a/collects/games/cards/card-class.rkt
+++ b/collects/games/cards/card-class.rkt
@@ -4,8 +4,8 @@
 	   mzlib/class100
            mzlib/shared
 	   (prefix mred: mred)
-	   "snipclass.ss"
-	   "region.ss"
+	   "snipclass.rkt"
+	   "region.rkt"
            (only scheme/base for in-range))
 
   (provide card%)
diff --git a/collects/games/cards/cards.rkt b/collects/games/cards/cards.rkt
index 03e051cfc9..ccb388913e 100644
--- a/collects/games/cards/cards.rkt
+++ b/collects/games/cards/cards.rkt
@@ -1,8 +1,7 @@
-
 (module cards mzscheme
-  (require "base.ss"
-	   "utils.ss"
-	   "region.ss")
+  (require "base.rkt"
+           "utils.rkt"
+           "region.rkt")
 
   (provide table<%> card<%>
            region struct:region
@@ -18,4 +17,3 @@
 	   make-table
 
 	   shuffle-list))
-
diff --git a/collects/games/cards/classes.rkt b/collects/games/cards/classes.rkt
index ee828faf87..437957cbdc 100644
--- a/collects/games/cards/classes.rkt
+++ b/collects/games/cards/classes.rkt
@@ -1,17 +1,16 @@
-
 (module classes mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   (prefix mred: mred)
-	   mzlib/list
-	   mzlib/etc
-	   (prefix util: "utils.ss")
-	   "constants.ss"
-	   "make-cards.ss"
-	   "region.ss"
-	   string-constants
-	   "../show-help.ss"
-	   "../show-scribbling.ss")
+           mzlib/class100
+           (prefix mred: mred)
+           mzlib/list
+           mzlib/etc
+           (prefix util: "utils.rkt")
+           "constants.rkt"
+           "make-cards.rkt"
+           "region.rkt"
+           string-constants
+           "../show-help.rkt"
+           "../show-scribbling.rkt")
 
   (provide pasteboard%
 	   table%)
diff --git a/collects/games/cards/main.rkt b/collects/games/cards/main.rkt
index 9d4d3b7515..5ee1d83120 100644
--- a/collects/games/cards/main.rkt
+++ b/collects/games/cards/main.rkt
@@ -1,4 +1,4 @@
 #lang mzscheme
 
-(require "cards.ss")
-(provide (all-from "cards.ss"))
+(require "cards.rkt")
+(provide (all-from "cards.rkt"))
diff --git a/collects/games/cards/make-cards.rkt b/collects/games/cards/make-cards.rkt
index 38da0dcbd4..c198d18b44 100644
--- a/collects/games/cards/make-cards.rkt
+++ b/collects/games/cards/make-cards.rkt
@@ -1,9 +1,8 @@
-
 (module make-cards mzscheme
   (require mzlib/class
-	   (prefix mred: mred)
-	   (prefix card-class: "card-class.ss"))
-  
+           (prefix mred: mred)
+           (prefix card-class: "card-class.rkt"))
+
   (provide back deck-of-cards make-card)
 
   (define (get-bitmap file)
diff --git a/collects/games/chat-noir/chat-noir-unit.rkt b/collects/games/chat-noir/chat-noir-unit.rkt
index ba1b8521ea..ef16d5ba5e 100644
--- a/collects/games/chat-noir/chat-noir-unit.rkt
+++ b/collects/games/chat-noir/chat-noir-unit.rkt
@@ -3,14 +3,14 @@
          scheme/runtime-path
          scheme/gui/base
          scheme/class
-         "../show-scribbling.ss"
+         "../show-scribbling.rkt"
          string-constants/string-constant
          (prefix-in x: lang/htdp-intermediate-lambda)
          (prefix-in y: htdp/world))
 
 (provide game@)
 (define orig-namespace (current-namespace))
-(define-runtime-path chat-noir "chat-noir-literate.ss")
+(define-runtime-path chat-noir "chat-noir-literate.rkt")
 
 (define-unit game@
   (import)
@@ -67,7 +67,7 @@
   
   (parameterize ([current-custodian sub-custodian])
     (parameterize ([current-namespace (make-base-namespace)])
-      (namespace-attach-module orig-namespace '(lib "mred.ss" "mred"))
-      (namespace-attach-module orig-namespace '(lib "class.ss" "scheme"))
+      (namespace-attach-module orig-namespace '(lib "mred.rkt" "mred"))
+      (namespace-attach-module orig-namespace '(lib "class.rkt" "scheme"))
       ((dynamic-require chat-noir 'main)))))
 
diff --git a/collects/games/chat-noir/info.rkt b/collects/games/chat-noir/info.rkt
index 5c94ee961b..6c70f960a8 100644
--- a/collects/games/chat-noir/info.rkt
+++ b/collects/games/chat-noir/info.rkt
@@ -1,6 +1,6 @@
 #lang setup/infotab
 
-(define game "chat-noir-unit.ss")
+(define game "chat-noir-unit.rkt")
 (define game-set "Puzzle Games")
-(define compile-omit-files '("chat-noir.ss"))
+(define compile-omit-files '("chat-noir.rkt"))
 (define name "Chat Noir")
diff --git a/collects/games/checkers/checkers.rkt b/collects/games/checkers/checkers.rkt
index 93aa6d03d8..6b78e3c2dc 100644
--- a/collects/games/checkers/checkers.rkt
+++ b/collects/games/checkers/checkers.rkt
@@ -10,7 +10,7 @@
          sgl/gl
          srfi/25/array
          mrlib/include-bitmap
-         "honu-bitmaps.ss")
+         "honu-bitmaps.rkt")
 (provide game@)
 
 (define-struct image (width height rgba))
diff --git a/collects/games/checkers/info.rkt b/collects/games/checkers/info.rkt
index 81fdba2acc..e3bc381964 100644
--- a/collects/games/checkers/info.rkt
+++ b/collects/games/checkers/info.rkt
@@ -1,4 +1,4 @@
 #lang setup/infotab
 
-(define game "checkers.ss")
+(define game "checkers.rkt")
 (define game-set "Board Games")
diff --git a/collects/games/crazy8s/info.rkt b/collects/games/crazy8s/info.rkt
index 62d046aaed..939e7bb411 100644
--- a/collects/games/crazy8s/info.rkt
+++ b/collects/games/crazy8s/info.rkt
@@ -1,5 +1,5 @@
 #lang setup/infotab
 
 (define name "Crazy 8s")
-(define game "crazy8s.ss")
+(define game "crazy8s.rkt")
 (define game-set "Card Games")
diff --git a/collects/games/doors/graph.rkt b/collects/games/doors/graph.rkt
index 9418e9ca92..af25b80cdb 100644
--- a/collects/games/doors/graph.rkt
+++ b/collects/games/doors/graph.rkt
@@ -1,8 +1,7 @@
-
 (module graph mzscheme
   (require mzlib/class
-           "private/utils.ss")
-  (require-for-syntax "private/utils.ss")
+           "private/utils.rkt")
+  (require-for-syntax "private/utils.rkt")
 
   (provide node% edge% 
            grid-graph)
diff --git a/collects/games/doors/utils.rkt b/collects/games/doors/utils.rkt
index 1a91a92370..8c98ef0a76 100644
--- a/collects/games/doors/utils.rkt
+++ b/collects/games/doors/utils.rkt
@@ -7,7 +7,7 @@
            mzlib/etc
            mzlib/class
            mzlib/kw
-           "doors.ss")
+           "doors.rkt")
   
   (provide door-bm
            magic-door-bm
diff --git a/collects/games/gcalc/gcalc.rkt b/collects/games/gcalc/gcalc.rkt
index 79d22d02a3..50eaa38099 100644
--- a/collects/games/gcalc/gcalc.rkt
+++ b/collects/games/gcalc/gcalc.rkt
@@ -5,7 +5,7 @@
 
 #lang mzscheme
 
-(require mzlib/class mred mzlib/etc "../show-scribbling.ss" mzlib/unit)
+(require mzlib/class mred mzlib/etc "../show-scribbling.rkt" mzlib/unit)
 (provide game@)
 
 (define customs '())
diff --git a/collects/games/gcalc/info.rkt b/collects/games/gcalc/info.rkt
index cd2510e46d..91b0454d9e 100644
--- a/collects/games/gcalc/info.rkt
+++ b/collects/games/gcalc/info.rkt
@@ -1,4 +1,4 @@
 #lang setup/infotab
 
 (define name "GCalc")
-(define game "gcalc.ss")
+(define game "gcalc.rkt")
diff --git a/collects/games/ginrummy/info.rkt b/collects/games/ginrummy/info.rkt
index 656fb15e49..c47a1d5dc2 100644
--- a/collects/games/ginrummy/info.rkt
+++ b/collects/games/ginrummy/info.rkt
@@ -1,5 +1,5 @@
 #lang setup/infotab
 
 (define name "Rummy")
-(define game "ginrummy.ss")
+(define game "ginrummy.rkt")
 (define game-set "Card Games")
diff --git a/collects/games/gl-board-game.rkt b/collects/games/gl-board-game.rkt
index 00214d2518..e59d0eae6c 100644
--- a/collects/games/gl-board-game.rkt
+++ b/collects/games/gl-board-game.rkt
@@ -1,4 +1,4 @@
 #lang scheme/base
 
-(require "gl-board-game/gl-board.ss")
-(provide (all-from-out "gl-board-game/gl-board.ss"))
+(require "gl-board-game/gl-board.rkt")
+(provide (all-from-out "gl-board-game/gl-board.rkt"))
diff --git a/collects/games/gl-board-game/main.rkt b/collects/games/gl-board-game/main.rkt
index 0f058064b4..00a08f7f9d 100644
--- a/collects/games/gl-board-game/main.rkt
+++ b/collects/games/gl-board-game/main.rkt
@@ -1,4 +1,4 @@
 #lang scheme/base
 
-(require "gl-board.ss")
-(provide (all-from-out "gl-board.ss"))
+(require "gl-board.rkt")
+(provide (all-from-out "gl-board.rkt"))
diff --git a/collects/games/gobblet/check.rkt b/collects/games/gobblet/check.rkt
index ac2f0465e8..19d3e706a8 100644
--- a/collects/games/gobblet/check.rkt
+++ b/collects/games/gobblet/check.rkt
@@ -1,4 +1,3 @@
-
 ;; Checks that all paths in a tree of games leads to the expected
 ;; winner. It also generates information for known plays to be used to
 ;; speed up future games (i.e., converts learned strategy to a compact
@@ -6,12 +5,12 @@
 
 (module check mzscheme
   (require mzlib/unitsig
-	   mzlib/etc
-	   mzlib/list
-	   "sig.ss"
-	   "model.ss"
-	   "explore.ss"
-	   "heuristics.ss")
+           mzlib/etc
+           mzlib/list
+           "sig.rkt"
+           "model.rkt"
+           "explore.rkt"
+           "heuristics.rkt")
 
   (define board-size 3)
   (define cannon-size +inf.0)
diff --git a/collects/games/gobblet/explore.rkt b/collects/games/gobblet/explore.rkt
index 23cc15946d..321915ea68 100644
--- a/collects/games/gobblet/explore.rkt
+++ b/collects/games/gobblet/explore.rkt
@@ -1,13 +1,12 @@
-
 ;; This is the main search engine for auto-play.
 ;; See `make-search' for the main entry point.
 
 (module explore mzscheme
   (require mzlib/unitsig
-	   mzlib/etc
-	   mzlib/list
-	   "sig.ss"
-	   "test.ss")
+           mzlib/etc
+           mzlib/list
+           "sig.rkt"
+           "test.rkt")
 
   (provide explore-unit)
 
@@ -544,9 +543,10 @@
       ;;  Multi-run memory:
 
       (define learn? #f)
-      (define MEMORY-FILE (and learn?
-			       (build-path (find-system-path 'addon-dir)
-					   (format "gobblet-memory-~a.ss" BOARD-SIZE))))
+      (define MEMORY-FILE
+        (and learn?
+             (build-path (find-system-path 'addon-dir)
+                         (format "gobblet-memory-~a.rktd" BOARD-SIZE))))
 
       (define (record-result plays board me config init-memory)
         (when (or (found-win? plays)
diff --git a/collects/games/gobblet/gobblet.rkt b/collects/games/gobblet/gobblet.rkt
index d081921362..883245c024 100644
--- a/collects/games/gobblet/gobblet.rkt
+++ b/collects/games/gobblet/gobblet.rkt
@@ -3,12 +3,12 @@
          (only mzlib/unit unit import export)
          mzlib/file
          mred
-         "sig.ss"
-         "model.ss"
-         "gui.ss"
-         "heuristics.ss"
-         "explore.ss"
-         "../show-scribbling.ss")
+         "sig.rkt"
+         "model.rkt"
+         "gui.rkt"
+         "heuristics.rkt"
+         "explore.rkt"
+         "../show-scribbling.rkt")
 
 (provide game@)
 
diff --git a/collects/games/gobblet/gui.rkt b/collects/games/gobblet/gui.rkt
index cb9e976476..5611090bc4 100644
--- a/collects/games/gobblet/gui.rkt
+++ b/collects/games/gobblet/gui.rkt
@@ -1,12 +1,12 @@
 (module gui mzscheme
   (require games/gl-board-game/gl-board
            mzlib/class
-	   mred
+           mred
            mzlib/file
            sgl/gl-vectors
            sgl
-	   mzlib/unitsig
-	   "sig.ss")
+           mzlib/unitsig
+           "sig.rkt")
 
   (provide gui-unit)
   
diff --git a/collects/games/gobblet/heuristics.rkt b/collects/games/gobblet/heuristics.rkt
index c5f7bd3c9c..a3361c0358 100644
--- a/collects/games/gobblet/heuristics.rkt
+++ b/collects/games/gobblet/heuristics.rkt
@@ -1,13 +1,12 @@
-
 ;; Supplies canned moves and board-rating functions for the state
 ;; explorer.
 
 (module heuristics mzscheme
   (require mzlib/unitsig
-	   mzlib/etc
-	   mzlib/list
-	   "sig.ss"
-	   "plays-3x3.ss")
+           mzlib/etc
+           mzlib/list
+           "sig.rkt"
+           "plays-3x3.rkt")
 
   (provide heuristics-unit)
 
diff --git a/collects/games/gobblet/info.rkt b/collects/games/gobblet/info.rkt
index a6e67b2043..1faa71a6fe 100644
--- a/collects/games/gobblet/info.rkt
+++ b/collects/games/gobblet/info.rkt
@@ -1,4 +1,4 @@
 #lang setup/infotab
 
-(define game "gobblet.ss")
+(define game "gobblet.rkt")
 (define game-set "Board Games")
diff --git a/collects/games/gobblet/model.rkt b/collects/games/gobblet/model.rkt
index cb6c44257d..f6e7d8f4d5 100644
--- a/collects/games/gobblet/model.rkt
+++ b/collects/games/gobblet/model.rkt
@@ -1,10 +1,10 @@
 (module model mzscheme
-  (require "sig.ss"
-	   mzlib/unitsig)
+  (require "sig.rkt"
+           mzlib/unitsig)
 
   (provide model-unit)
 
-  ;; Most tests are in test-model.ss, but for better coverage,
+  ;; Most tests are in test-model.rkt, but for better coverage,
   ;; uncomment the tests below for unexported functions when running
   ;; the test suite.
   
@@ -408,7 +408,7 @@
       ;; Generate a numerical ID for each stack. This numerical
       ;;  ID must stay constant for all of time, because we
       ;;  record boards in compact form using these numbers.
-      ;;  (For example, see "plays-3x3.ss".)
+      ;;  (For example, see "plays-3x3.rkt".)
       (define red-stack-ids (make-hash-table))
       (define yellow-stack-ids (make-hash-table))
       (for-each (lambda (s)
diff --git a/collects/games/gobblet/plays-3x3.rkt b/collects/games/gobblet/plays-3x3.rkt
index 640f559680..b86a6919f5 100644
--- a/collects/games/gobblet/plays-3x3.rkt
+++ b/collects/games/gobblet/plays-3x3.rkt
@@ -1,7 +1,7 @@
 (module plays-3x3 mzscheme
   (provide 3x3-plays)
   (define 3x3-plays
-    ;; This list is generated by "check.ss".
+    ;; This list is generated by "check.rkt".
     ;; Generate it only when red knows how to win
     ;; from all boards.
     '((#9(15 0 0 21 9 0 0 0 18) 1 #f 6 2)
diff --git a/collects/games/gobblet/robot.rkt b/collects/games/gobblet/robot.rkt
index af9a114d85..42a5b66cd7 100644
--- a/collects/games/gobblet/robot.rkt
+++ b/collects/games/gobblet/robot.rkt
@@ -1,14 +1,13 @@
-
-;; Plays automatic games, often useful when learning is enabled in explore.ss
+;; Plays automatic games, often useful when learning is enabled in "explore.rkt"
 
 (module robot mzscheme
   (require mzlib/unitsig
            mzlib/etc
            mzlib/list
-           "sig.ss"
-           "model.ss"
-           "explore.ss"
-           "heuristics.ss")
+           "sig.rkt"
+           "model.rkt"
+           "explore.rkt"
+           "heuristics.rkt")
   
   (define board-size 3)
   (define steps 2)
diff --git a/collects/games/gobblet/test-explore.rkt b/collects/games/gobblet/test-explore.rkt
index 17ee355e77..2fe390a897 100644
--- a/collects/games/gobblet/test-explore.rkt
+++ b/collects/games/gobblet/test-explore.rkt
@@ -1,12 +1,11 @@
-
 (module test-explore mzscheme
   (require mzlib/unitsig
-	   mzlib/etc
-	   mzlib/list
-	   "sig.ss"
-	   "model.ss"
-	   "explore.ss"
-	   "heuristics.ss")
+           mzlib/etc
+           mzlib/list
+           "sig.rkt"
+           "model.rkt"
+           "explore.rkt"
+           "heuristics.rkt")
 
   (define board-size 3)
 
diff --git a/collects/games/gobblet/test-model.rkt b/collects/games/gobblet/test-model.rkt
index f92f4cf2a4..03df53c5b8 100644
--- a/collects/games/gobblet/test-model.rkt
+++ b/collects/games/gobblet/test-model.rkt
@@ -1,13 +1,12 @@
-
 ;; Some tests for the model
 
 (module test-model mzscheme
   (require mzlib/unitsig
-	   mzlib/etc
-	   mzlib/list
-	   "sig.ss"
-	   "model.ss"
-	   "test.ss")
+           mzlib/etc
+           mzlib/list
+           "sig.rkt"
+           "model.rkt"
+           "test.rkt")
 
   ;; Test basic procs:
   (define (test-folding n)
diff --git a/collects/games/gofish/info.rkt b/collects/games/gofish/info.rkt
index ccefee6ff6..ce1fe75821 100644
--- a/collects/games/gofish/info.rkt
+++ b/collects/games/gofish/info.rkt
@@ -1,5 +1,5 @@
 #lang setup/infotab
 
 (define name "Go Fish")
-(define game "gofish.ss")
+(define game "gofish.rkt")
 (define game-set "Card Games")
diff --git a/collects/games/info.rkt b/collects/games/info.rkt
index 389b3d9296..f6727d7ffc 100644
--- a/collects/games/info.rkt
+++ b/collects/games/info.rkt
@@ -2,5 +2,5 @@
 
 (define scribblings '(("scribblings/games.scrbl" (multi-page) (gui-library))))
 
-(define mred-launcher-libraries (list "main.ss"))
+(define mred-launcher-libraries (list "main.rkt"))
 (define mred-launcher-names (list "PLT Games"))
diff --git a/collects/games/lights-out/board.rkt b/collects/games/lights-out/board.rkt
index bda7a8b7ba..a4d69ad0d6 100644
--- a/collects/games/lights-out/board.rkt
+++ b/collects/games/lights-out/board.rkt
@@ -2,7 +2,7 @@
   (require mred
            mzlib/class
            mzlib/etc
-           "boards.ss")
+           "boards.rkt")
 
   (provide
    new-board      ;; : (-> board)  querys user
diff --git a/collects/games/lights-out/info.rkt b/collects/games/lights-out/info.rkt
index d6d1b2b776..518d0b4cbe 100644
--- a/collects/games/lights-out/info.rkt
+++ b/collects/games/lights-out/info.rkt
@@ -1,4 +1,4 @@
 #lang setup/infotab
 
 (define game-set "Puzzle Games")
-(define game "lights-out.ss")
+(define game "lights-out.rkt")
diff --git a/collects/games/lights-out/lights-out.rkt b/collects/games/lights-out/lights-out.rkt
index 6bdb4c92db..789e68bfc0 100644
--- a/collects/games/lights-out/lights-out.rkt
+++ b/collects/games/lights-out/lights-out.rkt
@@ -1,6 +1,6 @@
 #lang mzscheme
-(require "board.ss"
-         "../show-scribbling.ss"
+(require "board.rkt"
+         "../show-scribbling.rkt"
          mred
          mzlib/class
          mzlib/unit)
diff --git a/collects/games/main.rkt b/collects/games/main.rkt
index 89564a79d9..2b33f6bf0f 100644
--- a/collects/games/main.rkt
+++ b/collects/games/main.rkt
@@ -1,6 +1,6 @@
 #lang racket/gui
 
-(require setup/getinfo mrlib/bitmap-label "show-help.ss")
+(require setup/getinfo mrlib/bitmap-label "show-help.rkt")
 
 (define-struct game (file name set icon))
 
diff --git a/collects/games/memory/info.rkt b/collects/games/memory/info.rkt
index f8ee7ed4c9..60ac15e76d 100644
--- a/collects/games/memory/info.rkt
+++ b/collects/games/memory/info.rkt
@@ -1,4 +1,4 @@
 #lang setup/infotab
 
-(define game "memory.ss")
+(define game "memory.rkt")
 (define game-set "Card Games")
diff --git a/collects/games/mines/info.rkt b/collects/games/mines/info.rkt
index 8b286af017..e2772eab42 100644
--- a/collects/games/mines/info.rkt
+++ b/collects/games/mines/info.rkt
@@ -2,4 +2,4 @@
 
 (define name "Minesweeper")
 (define game-set "Puzzle Games")
-(define game "mines.ss")
+(define game "mines.rkt")
diff --git a/collects/games/paint-by-numbers/all-problems.rkt b/collects/games/paint-by-numbers/all-problems.rkt
index 00d62541fe..ed977fee0d 100644
--- a/collects/games/paint-by-numbers/all-problems.rkt
+++ b/collects/games/paint-by-numbers/all-problems.rkt
@@ -3,7 +3,7 @@
            mzlib/list
            mzlib/unitsig
            mzlib/include
-           "problem.ss")
+           "problem.rkt")
 
   (require-for-syntax mzlib/etc)
 
diff --git a/collects/games/paint-by-numbers/info.rkt b/collects/games/paint-by-numbers/info.rkt
index 535a9343f6..0ea3bd66b7 100644
--- a/collects/games/paint-by-numbers/info.rkt
+++ b/collects/games/paint-by-numbers/info.rkt
@@ -1,6 +1,6 @@
 #lang setup/infotab
 
-(define game "paint-by-numbers.ss")
+(define game "paint-by-numbers.rkt")
 (define game-set "Puzzle Games")
 (define compile-omit-paths
   '("main.rkt"
diff --git a/collects/games/paint-by-numbers/main.rkt b/collects/games/paint-by-numbers/main.rkt
index eaab6a9169..2e9ebf76e3 100644
--- a/collects/games/paint-by-numbers/main.rkt
+++ b/collects/games/paint-by-numbers/main.rkt
@@ -44,7 +44,7 @@
 	  (send g set-value counter)]))))
 
   (define show-help
-    ((require-library "show-help.ss" "games")
+    ((require-library "show-help.rkt" "games")
      (list "games" "paint-by-numbers")
      "Paint by Numbers Help"))
 
diff --git a/collects/games/paint-by-numbers/paint-by-numbers.rkt b/collects/games/paint-by-numbers/paint-by-numbers.rkt
index 47c91dc3b4..e148c88500 100644
--- a/collects/games/paint-by-numbers/paint-by-numbers.rkt
+++ b/collects/games/paint-by-numbers/paint-by-numbers.rkt
@@ -1,10 +1,9 @@
-
 (module paint-by-numbers mzscheme
-  (require "gui.ss" 
-           (prefix solve: "solve.ss")
-           "all-problems.ss"
-           "problem.ss"
-           "../show-scribbling.ss"
+  (require "gui.rkt"
+           (prefix solve: "solve.rkt")
+           "all-problems.rkt"
+           "problem.rkt"
+           "../show-scribbling.rkt"
            framework
            mzlib/class
            mzlib/unit
diff --git a/collects/games/paint-by-numbers/raw-problems/build-hattori.rkt b/collects/games/paint-by-numbers/raw-problems/build-hattori.rkt
index 552e81675b..f24405aa97 100644
--- a/collects/games/paint-by-numbers/raw-problems/build-hattori.rkt
+++ b/collects/games/paint-by-numbers/raw-problems/build-hattori.rkt
@@ -159,7 +159,7 @@
 
 (provide main)
 (define (main)
-  (call-with-output-file "raw-hattori.ss"
+  (call-with-output-file "raw-hattori.rkt"
     (lambda (port)
       (parameterize ([current-output-port port])
         (printf "`(\n")
diff --git a/collects/games/paint-by-numbers/raw-problems/build-rows-cols.rkt b/collects/games/paint-by-numbers/raw-problems/build-rows-cols.rkt
index 6d6c173b47..0dbf7d00f0 100644
--- a/collects/games/paint-by-numbers/raw-problems/build-rows-cols.rkt
+++ b/collects/games/paint-by-numbers/raw-problems/build-rows-cols.rkt
@@ -4,7 +4,7 @@
 (define argv (current-command-line-arguments))
 
 (when (equal? (vector) argv)
-  (error 'build-rows-cols.ss
+  (error 'build-rows-cols.rkt
 	 "expected an image file on the command-line"))
 	 
 (define image (vector-ref argv 0))
diff --git a/collects/games/paint-by-numbers/raw-problems/build-solution-sets.rkt b/collects/games/paint-by-numbers/raw-problems/build-solution-sets.rkt
index 94123af724..37abf3a419 100644
--- a/collects/games/paint-by-numbers/raw-problems/build-solution-sets.rkt
+++ b/collects/games/paint-by-numbers/raw-problems/build-solution-sets.rkt
@@ -2,14 +2,14 @@
 
 #|
 
-Shell script to read in the ../problems/raw-*.ss file and produce
+Shell script to read in the ../problems/raw-*.rkt file and produce
 the files in the ../solution-sets subdirectory via John's solver. 
 
 This file must produce code that evaluates to a list of problem
 structs. The problem struct should have four fields: a string, a col,
 a row and a (union #f solution)
 
-The col and row type specs are in sig.ss and the solution type is:
+The col and row type specs are in sig.rkt and the solution type is:
 
   (vectorof (vectorof (union 'on 'off 'unknown)))
 
@@ -24,8 +24,8 @@ The col and row type specs are in sig.ss and the solution type is:
          mzlib/pretty
          mzlib/class
          mred
-         "raw-hattori.ss"
-         (prefix solve: "../solve.ss"))
+         "raw-hattori.rkt"
+         (prefix solve: "../solve.rkt"))
 
 (if (equal? (vector) argv)
     (printf "pass any command line argument to skip the solver\n\n")
@@ -109,13 +109,13 @@ The col and row type specs are in sig.ss and the solution type is:
         output-file
         (call-with-input-file (build-path problems-dir input-file) (compose eval read))))
 
-(require "raw-problems.ss")
+(require "raw-problems.rkt")
 (define games-set (list "Games Magazine" "games" raw-problems))
 
-(require "raw-misc.ss")
+(require "raw-misc.rkt")
 (define misc-set (list "Misc" "misc" raw-misc))
 
-(require "raw-kajitani.ss")
+(require "raw-kajitani.rkt")
 (define kajitani-sets raw-kajitani)
 
 (define sets (append (list games-set)
@@ -252,13 +252,13 @@ The col and row type specs are in sig.ss and the solution type is:
         [cols (second problem)]
         [rows (third problem)])
     (when (null? cols)
-      (error 'build-problems.ss
+      (error 'build-solution-sets.rkt
              "problem ~a doesn't have any cols" name))
     (when (null? rows)
-      (error 'build-problems.ss
+      (error 'build-solution-sets.rkt
              "problem ~a doesn't have any rows" name))
     (unless (= (sum-lists cols) (sum-lists rows))
-      (error 'build-problems.ss
+      (error 'build-solution-sets.rkt
              "problem ~a: sum of the column lists is not the same as the sum of the row lists"
              name))))
 
diff --git a/collects/games/paint-by-numbers/raw-problems/raw-misc.rkt b/collects/games/paint-by-numbers/raw-problems/raw-misc.rkt
index 7b1284f62e..bf2b41aebe 100644
--- a/collects/games/paint-by-numbers/raw-problems/raw-misc.rkt
+++ b/collects/games/paint-by-numbers/raw-problems/raw-misc.rkt
@@ -3,16 +3,16 @@
 
 #|
 
-raw-misc.ss
+raw-misc.rkt
 
 This file contains the built-in problems in a raw format. It is
 intended to be processed by the solver which will produce
-`problems.ss'. This file should contain a single sexpression of this
+"problems.rkt". This file should contain a single sexpression of this
 type:
 
   (listof (list string cols rows))
 
-The cols and rows types are specified in sig.ss
+The cols and rows types are specified in sig.rkt
 
 |#
 (define raw-misc
diff --git a/collects/games/paint-by-numbers/raw-problems/raw-problems.rkt b/collects/games/paint-by-numbers/raw-problems/raw-problems.rkt
index 70d4f51034..988504b6d1 100644
--- a/collects/games/paint-by-numbers/raw-problems/raw-problems.rkt
+++ b/collects/games/paint-by-numbers/raw-problems/raw-problems.rkt
@@ -2,7 +2,7 @@
 
 #|
 
-raw-problems.ss
+raw-problems.rkt
 
 This file contains the built-in problems in a raw format. 
 This file should contain a single sexpression of this
@@ -10,7 +10,7 @@ type:
 
   (listof (list string cols rows))
 
-The cols and rows types are specified in sig.ss
+The cols and rows types are specified in sig.rkt
 
 |#
 
diff --git a/collects/games/paint-by-numbers/raw-problems/size-calculation.rkt b/collects/games/paint-by-numbers/raw-problems/size-calculation.rkt
index 78345eaed8..b2f6b48d48 100644
--- a/collects/games/paint-by-numbers/raw-problems/size-calculation.rkt
+++ b/collects/games/paint-by-numbers/raw-problems/size-calculation.rkt
@@ -1,6 +1,6 @@
 #lang scheme
 
-(require "raw-hattori.ss")
+(require "raw-hattori.rkt")
 
 (define (num-possibilities size col)
   (let* ([col-len (length col)]
diff --git a/collects/games/parcheesi/admin-gui.rkt b/collects/games/parcheesi/admin-gui.rkt
index c6db9d1259..eb7e6bc5f0 100644
--- a/collects/games/parcheesi/admin-gui.rkt
+++ b/collects/games/parcheesi/admin-gui.rkt
@@ -6,14 +6,14 @@ corresponds to the unplayed move! that's confusing.
 |#
 
 (module admin-gui mzscheme
-  (require "gui.ss"
-           "die.ss"
-           "interfaces.ss"
-           "admin.ss"
-           "board.ss"
-	   "moves.ss"
-           "rules.ss"
-           "best-players.ss"
+  (require "gui.rkt"
+           "die.rkt"
+           "interfaces.rkt"
+           "admin.rkt"
+           "board.rkt"
+           "moves.rkt"
+           "rules.rkt"
+           "best-players.rkt"
            framework
            mzlib/class
            mzlib/list
diff --git a/collects/games/parcheesi/admin.rkt b/collects/games/parcheesi/admin.rkt
index c52dda4af5..8cbcac4ece 100644
--- a/collects/games/parcheesi/admin.rkt
+++ b/collects/games/parcheesi/admin.rkt
@@ -1,8 +1,7 @@
-
 (module admin mzscheme
-  (require "board.ss"
-	   "moves.ss"
-           "interfaces.ss"
+  (require "board.rkt"
+           "moves.rkt"
+           "interfaces.rkt"
            mzlib/class
            mzlib/list)
   
diff --git a/collects/games/parcheesi/best-players.rkt b/collects/games/parcheesi/best-players.rkt
index 6110fd3c92..b5a918ed7c 100644
--- a/collects/games/parcheesi/best-players.rkt
+++ b/collects/games/parcheesi/best-players.rkt
@@ -11,10 +11,10 @@ careful charlie
 |#
 
 (module best-players mzscheme
-  (require "board.ss"
-	   "moves.ss"
-           "interfaces.ss"
-           "test.ss"
+  (require "board.rkt"
+           "moves.rkt"
+           "interfaces.rkt"
+           "test.rkt"
            mzlib/list
            mzlib/etc
            mzlib/class
@@ -701,7 +701,7 @@ another new board representation (vector of loc's)
     
     #;
     (require xml
-             "parse.ss")
+             "parse.rkt")
     #;
     (define (dump-out-candidates candidates)
       (let loop ([i 0]
@@ -721,7 +721,7 @@ another new board representation (vector of loc's)
     (printf "~s candidates\n" (length candidates2)))
   
   
-  ;(require "gui.ss") (show-board problem-board)
+  ;(require "gui.rkt") (show-board problem-board)
   #|
 cpu time: 12680 real time: 13855 gc time: 380
 candidates 2797 (avg moves 6.9878441186986056)
diff --git a/collects/games/parcheesi/gui.rkt b/collects/games/parcheesi/gui.rkt
index 3156a8a979..1b587fb9af 100644
--- a/collects/games/parcheesi/gui.rkt
+++ b/collects/games/parcheesi/gui.rkt
@@ -1,7 +1,6 @@
-
 (module gui mzscheme
-  (require "board.ss"
-	   "moves.ss"
+  (require "board.rkt"
+           "moves.rkt"
            mred
            mzlib/class
            mzlib/list
diff --git a/collects/games/parcheesi/info.rkt b/collects/games/parcheesi/info.rkt
index a898213f33..ce7db304ea 100644
--- a/collects/games/parcheesi/info.rkt
+++ b/collects/games/parcheesi/info.rkt
@@ -1,4 +1,4 @@
 #lang setup/infotab
 
-(define game "parcheesi.ss")
+(define game "parcheesi.rkt")
 (define game-set "Board Games")
diff --git a/collects/games/parcheesi/make-bitmap.rkt b/collects/games/parcheesi/make-bitmap.rkt
index 37d21914d7..475f0b406a 100644
--- a/collects/games/parcheesi/make-bitmap.rkt
+++ b/collects/games/parcheesi/make-bitmap.rkt
@@ -1,7 +1,6 @@
-
 (module make-bitmap mzscheme
-  (require "board.ss"
-	   "moves.ss"
+  (require "board.rkt"
+           "moves.rkt"
            mred
            mzlib/class
            mzlib/list
diff --git a/collects/games/parcheesi/moves.rkt b/collects/games/parcheesi/moves.rkt
index a70e088dac..f88d21e02d 100644
--- a/collects/games/parcheesi/moves.rkt
+++ b/collects/games/parcheesi/moves.rkt
@@ -1,5 +1,5 @@
 (module moves mzscheme
-  (require "board.ss"
+  (require "board.rkt"
            mzlib/contract
            mzlib/list)
 
diff --git a/collects/games/parcheesi/parcheesi.rkt b/collects/games/parcheesi/parcheesi.rkt
index 201f0bcee3..c53c176ac6 100644
--- a/collects/games/parcheesi/parcheesi.rkt
+++ b/collects/games/parcheesi/parcheesi.rkt
@@ -1,13 +1,10 @@
-
 (module parcheesi mzscheme
   (require mzlib/unit
            mzlib/class
-           "admin-gui.ss")
-  
+           "admin-gui.rkt")
+
   (provide game@)
   (define game@
     (unit (import)
           (export)
           (new gui-game%))))
-
-
diff --git a/collects/games/parcheesi/play-game.rkt b/collects/games/parcheesi/play-game.rkt
index 9d174768ba..5833b60584 100644
--- a/collects/games/parcheesi/play-game.rkt
+++ b/collects/games/parcheesi/play-game.rkt
@@ -1,9 +1,9 @@
 (module play-game mzscheme
-  (require "gui.ss"
-           "admin.ss"
-           "board.ss"
-	   "moves.ss"
-           "die.ss"
+  (require "gui.rkt"
+           "admin.rkt"
+           "board.rkt"
+           "moves.rkt"
+           "die.rkt"
            mzlib/math
            mzlib/class
            mred)
@@ -144,7 +144,7 @@
 
   #;
   (begin
-    (require "best-player.ss") 
+    (require "best-player.rkt") 
     (play-game (list (new first-player%) 
                      (new last-player%) 
                      (new first-player%) 
diff --git a/collects/games/parcheesi/rules.rkt b/collects/games/parcheesi/rules.rkt
index 76a041bd36..7e0ba94dc4 100644
--- a/collects/games/parcheesi/rules.rkt
+++ b/collects/games/parcheesi/rules.rkt
@@ -1,9 +1,9 @@
 (module rules mzscheme
   (provide show-rules)
   
-  (require "board.ss"
-           "moves.ss"
-           "gui.ss"
+  (require "board.rkt"
+           "moves.rkt"
+           "gui.rkt"
 
            mzlib/class
            xml
diff --git a/collects/games/pousse/board.rkt b/collects/games/pousse/board.rkt
index 78ec47e1ca..737ea7ff99 100644
--- a/collects/games/pousse/board.rkt
+++ b/collects/games/pousse/board.rkt
@@ -1,5 +1,5 @@
 (module board mzscheme
-  (require "board-size.ss") ; for n
+  (require "board-size.rkt") ; for n
   
   (provide x o none     ; cell values
 	   new-board    ; n => board
diff --git a/collects/games/pousse/counter.rkt b/collects/games/pousse/counter.rkt
index 39f51721b6..a7ff48d2a0 100644
--- a/collects/games/pousse/counter.rkt
+++ b/collects/games/pousse/counter.rkt
@@ -5,8 +5,8 @@
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 (module counter mzscheme
-  (require "board.ss"
-           "utils.ss"
+  (require "board.rkt"
+           "utils.rkt"
            mzlib/unitsig)
   
   (provide params^
diff --git a/collects/games/pousse/info.rkt b/collects/games/pousse/info.rkt
index 63f1b96690..ea99c8ea98 100644
--- a/collects/games/pousse/info.rkt
+++ b/collects/games/pousse/info.rkt
@@ -1,4 +1,4 @@
 #lang setup/infotab
 
-(define game "pousse.ss")
+(define game "pousse.rkt")
 (define game-set "Board Games")
diff --git a/collects/games/pousse/pousse.rkt b/collects/games/pousse/pousse.rkt
index 1e23632080..5894af1fc1 100644
--- a/collects/games/pousse/pousse.rkt
+++ b/collects/games/pousse/pousse.rkt
@@ -1,13 +1,13 @@
 (module pousse mzscheme
-  (require "utils.ss"
-           "board.ss"
-           "board-size.ss"
-           "../show-scribbling.ss"
+  (require "utils.rkt"
+           "board.rkt"
+           "board-size.rkt"
+           "../show-scribbling.rkt"
            mzlib/class
            mzlib/class100
            (all-except mzlib/unit rename) ; rename collides with class100
            mred
-           (prefix robot: "robot.ss"))
+           (prefix robot: "robot.rkt"))
   
   (provide game@)
   
diff --git a/collects/games/pousse/robot.rkt b/collects/games/pousse/robot.rkt
index 5ec4192d75..2b6feee7ce 100644
--- a/collects/games/pousse/robot.rkt
+++ b/collects/games/pousse/robot.rkt
@@ -1,7 +1,7 @@
 (module robot mzscheme
-  (require "counter.ss"
-           "board.ss"
-           "utils.ss"
+  (require "counter.rkt"
+           "board.rkt"
+           "utils.rkt"
            mzlib/unitsig)
   
   (provide robot)
diff --git a/collects/games/pousse/utils.rkt b/collects/games/pousse/utils.rkt
index 352660afb4..fee7d2080f 100644
--- a/collects/games/pousse/utils.rkt
+++ b/collects/games/pousse/utils.rkt
@@ -1,7 +1,7 @@
 (module utils mzscheme
-  ; See boardsig.ss for the core utilities.
-  (require "board-size.ss"
-           "board.ss")
+  ; See boardsig.rkt for the core utilities.
+  (require "board-size.rkt"
+           "board.rkt")
   
   (provide
    n-times      ; call a procedure with each number in [0, n]
diff --git a/collects/games/same/info.rkt b/collects/games/same/info.rkt
index 00ae903246..db20d73b2f 100644
--- a/collects/games/same/info.rkt
+++ b/collects/games/same/info.rkt
@@ -1,4 +1,4 @@
 #lang setup/infotab
 
 (define game-set "Puzzle Games")
-(define game "same.ss")
+(define game "same.rkt")
diff --git a/collects/games/same/same.rkt b/collects/games/same/same.rkt
index c1fabfbacc..f23a9fe6dd 100644
--- a/collects/games/same/same.rkt
+++ b/collects/games/same/same.rkt
@@ -4,7 +4,7 @@
          racket/list
          racket/gui/base
          racket/math
-         "../show-scribbling.ss"
+         "../show-scribbling.rkt"
          "same-lib.rkt")
 
 (provide game@)
diff --git a/collects/games/slidey/info.rkt b/collects/games/slidey/info.rkt
index 8194fa5102..922e912615 100644
--- a/collects/games/slidey/info.rkt
+++ b/collects/games/slidey/info.rkt
@@ -1,4 +1,4 @@
 #lang setup/infotab
 
 (define game-set "Puzzle Games")
-(define game "slidey.ss")
+(define game "slidey.rkt")
diff --git a/collects/games/spider/info.rkt b/collects/games/spider/info.rkt
index 0cf3a1be38..5cf0fcf5cc 100644
--- a/collects/games/spider/info.rkt
+++ b/collects/games/spider/info.rkt
@@ -1,4 +1,4 @@
 #lang setup/infotab
 
-(define game "spider.ss")
+(define game "spider.rkt")
 (define game-set "Card Games")
diff --git a/collects/games/spider/spider.rkt b/collects/games/spider/spider.rkt
index 08a76d0987..68af771ef2 100644
--- a/collects/games/spider/spider.rkt
+++ b/collects/games/spider/spider.rkt
@@ -1,7 +1,7 @@
 #lang mzscheme
 
 (require games/cards mred mzlib/class mzlib/list mzlib/file mzlib/unit
-         "../show-scribbling.ss")
+         "../show-scribbling.rkt")
 
 (define (list-first-n l n)
   (if (zero? n)
diff --git a/collects/graphics/graphics-posn-less-unit.rkt b/collects/graphics/graphics-posn-less-unit.rkt
index 9733a0c424..eb33d181eb 100644
--- a/collects/graphics/graphics-posn-less-unit.rkt
+++ b/collects/graphics/graphics-posn-less-unit.rkt
@@ -1,15 +1,14 @@
-; graphics.ss
 ; Simple graphics routines for GRacket
 ; Originally written by Johnathan Franklin
 
 (module graphics-posn-less-unit mzscheme
   (require mzlib/unit
-	   mred/mred-sig
+           mred/mred-sig
            mred
-	   mzlib/class
-	   mzlib/class100
-	   mzlib/etc
-	   "graphics-sig.ss")
+           mzlib/class
+           mzlib/class100
+           mzlib/etc
+           "graphics-sig.rkt")
   (provide graphics-posn-less@)
 
   (define-syntax define-do-pixel
diff --git a/collects/graphics/graphics-unit.rkt b/collects/graphics/graphics-unit.rkt
index 7957018803..423f42c090 100644
--- a/collects/graphics/graphics-unit.rkt
+++ b/collects/graphics/graphics-unit.rkt
@@ -1,8 +1,8 @@
 (module graphics-unit mzscheme
   (require mzlib/unit
-	   mred/mred-sig
-	   "graphics-sig.ss"
-	   "graphics-posn-less-unit.ss")
+           mred/mred-sig
+           "graphics-sig.rkt"
+           "graphics-posn-less-unit.rkt")
   (provide graphics@)
 
   (define-unit p@
diff --git a/collects/graphics/graphics.rkt b/collects/graphics/graphics.rkt
index 290abd85d6..0531f0fd95 100644
--- a/collects/graphics/graphics.rkt
+++ b/collects/graphics/graphics.rkt
@@ -1,9 +1,9 @@
 (module graphics mzscheme
   (require mzlib/unit
-	   mred/mred-sig
-	   mred/mred-unit
-	   "graphics-sig.ss"
-	   "graphics-unit.ss")
+           mred/mred-sig
+           mred/mred-unit
+           "graphics-sig.rkt"
+           "graphics-unit.rkt")
   (provide-signature-elements graphics^ graphics:posn^)
 
   (define-values/invoke-unit/infer
diff --git a/collects/graphics/main.rkt b/collects/graphics/main.rkt
index a9a6d294b5..34ca77c558 100644
--- a/collects/graphics/main.rkt
+++ b/collects/graphics/main.rkt
@@ -1,4 +1,4 @@
 #lang scheme/base
 
-(require "graphics.ss")
-(provide (all-from-out "graphics.ss"))
+(require "graphics.rkt")
+(provide (all-from-out "graphics.rkt"))
diff --git a/collects/graphics/turtle-test.rkt b/collects/graphics/turtle-test.rkt
index 8307df771e..14513112b9 100644
--- a/collects/graphics/turtle-test.rkt
+++ b/collects/graphics/turtle-test.rkt
@@ -2,9 +2,9 @@
   (require mred
            mzlib/class
            mzlib/math
-           "turtle-examples.ss"
-           "turtles.ss")
-  
+           "turtle-examples.rkt"
+           "turtles.rkt")
+
   (define frame (make-object frame% "Turtle Examples"))
   
   (define options
diff --git a/collects/graphics/value-turtles-examples.rkt b/collects/graphics/value-turtles-examples.rkt
index 57f73a8797..499a71969b 100644
--- a/collects/graphics/value-turtles-examples.rkt
+++ b/collects/graphics/value-turtles-examples.rkt
@@ -1,5 +1,5 @@
 (module value-turtles-examples mzscheme
-  (require "value-turtles.ss"
+  (require "value-turtles.rkt"
            mzlib/etc
            mzlib/math)
 
diff --git a/collects/graphics/value-turtles-test.rkt b/collects/graphics/value-turtles-test.rkt
index 9ffa859d81..69b562c8bd 100644
--- a/collects/graphics/value-turtles-test.rkt
+++ b/collects/graphics/value-turtles-test.rkt
@@ -1,6 +1,6 @@
 (module value-turtles-test mzscheme
-  (require "value-turtles-examples.ss"
-           "value-turtles.ss"
+  (require "value-turtles-examples.rkt"
+           "value-turtles.rkt"
            mred
            mzlib/class)
   
diff --git a/collects/gui-debugger/debug-tool.rkt b/collects/gui-debugger/debug-tool.rkt
index 8c71c0a20d..cc4757977d 100644
--- a/collects/gui-debugger/debug-tool.rkt
+++ b/collects/gui-debugger/debug-tool.rkt
@@ -7,11 +7,11 @@
            mred
            mzlib/match
            drscheme/tool
-           "marks.ss"
+           "marks.rkt"
            mrlib/switchable-button
            mrlib/bitmap-label
-           "annotator.ss"
-           "load-sandbox.ss"
+           "annotator.rkt"
+           "load-sandbox.rkt"
            framework
            string-constants
            lang/debugger-language-interface)
diff --git a/collects/gui-debugger/info.rkt b/collects/gui-debugger/info.rkt
index b0d71ec0b3..8db27a7d6b 100644
--- a/collects/gui-debugger/info.rkt
+++ b/collects/gui-debugger/info.rkt
@@ -1,5 +1,5 @@
 #lang setup/infotab
 
-(define tools '(("debug-tool.ss")))
+(define tools '(("debug-tool.rkt")))
 (define tool-names '("Graphical Debugger"))
 (define tool-icons '(("clanbomber-32x32.png" "gui-debugger" "icons")))
diff --git a/collects/gui-debugger/load-sandbox.rkt b/collects/gui-debugger/load-sandbox.rkt
index 3112a22146..463f7c083d 100644
--- a/collects/gui-debugger/load-sandbox.rkt
+++ b/collects/gui-debugger/load-sandbox.rkt
@@ -67,7 +67,7 @@
   
   
   
-  ; taken directly from mred.ss -- it's not exported...
+  ; taken directly from mred.rkt -- it's not exported...
   (define (build-input-port filename)
     (let ([p (open-input-file filename)])
       (port-count-lines! p)
diff --git a/collects/guibuilder/base.rkt b/collects/guibuilder/base.rkt
index c45da18d6b..f30c74115c 100644
--- a/collects/guibuilder/base.rkt
+++ b/collects/guibuilder/base.rkt
@@ -1,12 +1,11 @@
-
 (module base mzscheme
   (require (prefix mred: mred)
-	   mzlib/class
-	   mzlib/file
-	   mzlib/pretty
-	   mzlib/etc
-	   mzlib/list
-	   "utils.ss")
+           mzlib/class
+           mzlib/file
+           mzlib/pretty
+           mzlib/etc
+           mzlib/list
+           "utils.rkt")
 
   (define GB:SNIP-VERSION 5)
   (define MINOR-VERSION 0)
diff --git a/collects/guibuilder/canvas.rkt b/collects/guibuilder/canvas.rkt
index 38401f623a..44f5b312af 100644
--- a/collects/guibuilder/canvas.rkt
+++ b/collects/guibuilder/canvas.rkt
@@ -1,14 +1,13 @@
-
 (module canvas mzscheme
   (require (prefix mred: mred)
-	   mzlib/class
-	   mzlib/file
-	   mzlib/pretty
-	   mzlib/etc
-	   mzlib/list
-	   "utils.ss"
-	   "base.ss"
-	   "feature.ss")
+           mzlib/class
+           mzlib/file
+           mzlib/pretty
+           mzlib/etc
+           mzlib/list
+           "utils.rkt"
+           "base.rkt"
+           "feature.rkt")
 
   (define gb:make-canvas-hscroll-checkable-snip%
     (lambda (cl)
diff --git a/collects/guibuilder/feature.rkt b/collects/guibuilder/feature.rkt
index d7fab88210..7749f500a4 100644
--- a/collects/guibuilder/feature.rkt
+++ b/collects/guibuilder/feature.rkt
@@ -1,13 +1,12 @@
-
 (module feature mzscheme
   (require (prefix mred: mred)
-	   mzlib/class
-	   mzlib/file
-	   mzlib/pretty
-	   mzlib/etc
-	   mzlib/list
-	   "base.ss"
-	   "utils.ss")
+           mzlib/class
+           mzlib/file
+           mzlib/pretty
+           mzlib/etc
+           mzlib/list
+           "base.rkt"
+           "utils.rkt")
 
   ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;; Mixins for GUI features
diff --git a/collects/guibuilder/guibuilder.rkt b/collects/guibuilder/guibuilder.rkt
index 233ec1a953..5bebee4d0a 100644
--- a/collects/guibuilder/guibuilder.rkt
+++ b/collects/guibuilder/guibuilder.rkt
@@ -1,26 +1,25 @@
-
 (module guibuilder mzscheme
   (require (prefix mred: mred)
-	   mzlib/class
-	   mzlib/file
-	   mzlib/pretty
-	   mzlib/etc
-	   mzlib/list
-	   (prefix framework: framework)
-	   "utils.ss"
-	   "top-level.ss"
-	   "toolbar.ss")
+           mzlib/class
+           mzlib/file
+           mzlib/pretty
+           mzlib/etc
+           mzlib/list
+           (prefix framework: framework)
+           "utils.rkt"
+           "top-level.rkt"
+           "toolbar.rkt")
 
   ;; These modules implement snips for the various
   ;;  kinds of windows and controls.
-  (require "base.ss"
-	   "panel.ss"
-	   "simple-control.ss"
-	   "text-field.ss"
-	   "multiple-choice.ss"
-	   "slider-guage.ss"
-	   "canvas.ss")
-  
+  (require "base.rkt"
+           "panel.rkt"
+           "simple-control.rkt"
+           "text-field.rkt"
+           "multiple-choice.rkt"
+           "slider-guage.rkt"
+           "canvas.rkt")
+
   (define my-base-frame% framework:frame:editor%)
 
   (define gb:frame%
diff --git a/collects/guibuilder/info.rkt b/collects/guibuilder/info.rkt
index 64237064ab..549754130b 100644
--- a/collects/guibuilder/info.rkt
+++ b/collects/guibuilder/info.rkt
@@ -1,4 +1,4 @@
 #lang setup/infotab
 
-(define tools '(("tool.ss")))
+(define tools '(("tool.rkt")))
 (define tool-names '("GUI Builder"))
diff --git a/collects/guibuilder/multiple-choice.rkt b/collects/guibuilder/multiple-choice.rkt
index 29f22cca42..2fa254b52e 100644
--- a/collects/guibuilder/multiple-choice.rkt
+++ b/collects/guibuilder/multiple-choice.rkt
@@ -1,15 +1,14 @@
-
 (module multiple-choice mzscheme
   (require (prefix mred: mred)
-	   mzlib/class
-	   mzlib/file
-	   mzlib/pretty
-	   mzlib/etc
-	   mzlib/list
-	   "utils.ss"
-	   "base.ss"
-	   "feature.ss")
-  
+           mzlib/class
+           mzlib/file
+           mzlib/pretty
+           mzlib/etc
+           mzlib/list
+           "utils.rkt"
+           "base.rkt"
+           "feature.rkt")
+
   (define gb:make-item-list-snip%
     (lambda (cl)
       (class cl
diff --git a/collects/guibuilder/panel.rkt b/collects/guibuilder/panel.rkt
index e1be9edc83..ddcf2a1f48 100644
--- a/collects/guibuilder/panel.rkt
+++ b/collects/guibuilder/panel.rkt
@@ -1,13 +1,12 @@
-
 (module panel mzscheme
   (require (prefix mred: mred)
-	   mzlib/class
-	   mzlib/file
-	   mzlib/pretty
-	   mzlib/etc
-	   mzlib/list
-	   "utils.ss"
-	   "base.ss")
+           mzlib/class
+           mzlib/file
+           mzlib/pretty
+           mzlib/etc
+           mzlib/list
+           "utils.rkt"
+           "base.rkt")
 
   (define gb:make-panel-params-snip%
     (lambda (cl)
diff --git a/collects/guibuilder/readable.rkt b/collects/guibuilder/readable.rkt
index 80e49a41f7..166b33c0e4 100644
--- a/collects/guibuilder/readable.rkt
+++ b/collects/guibuilder/readable.rkt
@@ -1,9 +1,8 @@
-
 (module readable mzscheme
   (require mred
            mzlib/class
-	   "top-level.ss"
-	   "toolbar.ss")
+           "top-level.rkt"
+           "toolbar.rkt")
 
   (define gui-snip-class%
     (class snip-class%
diff --git a/collects/guibuilder/simple-control.rkt b/collects/guibuilder/simple-control.rkt
index de81759ef2..cf21d4774f 100644
--- a/collects/guibuilder/simple-control.rkt
+++ b/collects/guibuilder/simple-control.rkt
@@ -1,14 +1,13 @@
-
 (module simple-control mzscheme
   (require (prefix mred: mred)
-	   mzlib/class
-	   mzlib/file
-	   mzlib/pretty
-	   mzlib/etc
-	   mzlib/list
-	   "utils.ss"
-	   "base.ss"
-	   "feature.ss")
+           mzlib/class
+           mzlib/file
+           mzlib/pretty
+           mzlib/etc
+           mzlib/list
+           "utils.rkt"
+           "base.rkt"
+           "feature.rkt")
 
   (define gb:make-message-snip%
     (lambda (cl cn)
diff --git a/collects/guibuilder/slider-guage.rkt b/collects/guibuilder/slider-guage.rkt
index e9af9b0d06..c04fb0a0ff 100644
--- a/collects/guibuilder/slider-guage.rkt
+++ b/collects/guibuilder/slider-guage.rkt
@@ -1,15 +1,14 @@
-
 (module slider-guage mzscheme
   (require (prefix mred: mred)
-	   mzlib/class
-	   mzlib/file
-	   mzlib/pretty
-	   mzlib/etc
-	   mzlib/list
-	   "utils.ss"
-	   "base.ss"
-	   "feature.ss")
-    
+           mzlib/class
+           mzlib/file
+           mzlib/pretty
+           mzlib/etc
+           mzlib/list
+           "utils.rkt"
+           "base.rkt"
+           "feature.rkt")
+
   (define gb:make-slider-snip%
     (lambda (cl cn)
       (class cl
diff --git a/collects/guibuilder/text-field.rkt b/collects/guibuilder/text-field.rkt
index 0f5bd7306a..3148ac857c 100644
--- a/collects/guibuilder/text-field.rkt
+++ b/collects/guibuilder/text-field.rkt
@@ -1,14 +1,13 @@
-
 (module text-field mzscheme
   (require (prefix mred: mred)
-	   mzlib/class
-	   mzlib/file
-	   mzlib/pretty
-	   mzlib/etc
-	   mzlib/list
-	   "utils.ss"
-	   "base.ss"
-	   "feature.ss")
+           mzlib/class
+           mzlib/file
+           mzlib/pretty
+           mzlib/etc
+           mzlib/list
+           "utils.rkt"
+           "base.rkt"
+           "feature.rkt")
 
   (define gb:make-text-initial-snip%
     (lambda (cl)
diff --git a/collects/guibuilder/tool.rkt b/collects/guibuilder/tool.rkt
index ecdb0a7c6b..7d226f641b 100644
--- a/collects/guibuilder/tool.rkt
+++ b/collects/guibuilder/tool.rkt
@@ -1,14 +1,13 @@
-
 (module tool mzscheme
   (require drscheme/tool
            mred
            mzlib/unit
            mzlib/class
-	   string-constants
-	   mzlib/contract
-           "top-level.ss"
-	   "toolbar.ss"
-	   "readable.ss")
+           string-constants
+           mzlib/contract
+           "top-level.rkt"
+           "toolbar.rkt"
+           "readable.rkt")
 
   (provide tool@)
 
diff --git a/collects/guibuilder/toolbar.rkt b/collects/guibuilder/toolbar.rkt
index 4a80fed0db..d1e964eefc 100644
--- a/collects/guibuilder/toolbar.rkt
+++ b/collects/guibuilder/toolbar.rkt
@@ -1,23 +1,22 @@
-
 (module toolbar mzscheme
   (require (prefix mred: mred)
-	   mzlib/class
-	   mzlib/file
-	   mzlib/pretty
-	   mzlib/etc
-	   mzlib/list
-	   "utils.ss")
+           mzlib/class
+           mzlib/file
+           mzlib/pretty
+           mzlib/etc
+           mzlib/list
+           "utils.rkt")
 
   ;; These modules implement snips for the various
   ;;  kinds of windows and controls.
-  (require "base.ss"
-	   "panel.ss"
-	   "simple-control.ss"
-	   "text-field.ss"
-	   "multiple-choice.ss"
-	   "slider-guage.ss"
-	   "canvas.ss")
-  
+  (require "base.rkt"
+           "panel.rkt"
+           "simple-control.rkt"
+           "text-field.rkt"
+           "multiple-choice.rkt"
+           "slider-guage.rkt"
+           "canvas.rkt")
+
   ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;; Frame
   ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
diff --git a/collects/guibuilder/top-level.rkt b/collects/guibuilder/top-level.rkt
index e047daf455..934005301d 100644
--- a/collects/guibuilder/top-level.rkt
+++ b/collects/guibuilder/top-level.rkt
@@ -7,9 +7,9 @@
          racket/list
          (prefix-in mred: racket/gui)
          (prefix-in framework: framework)
-         "utils.ss"
-         "base.ss"
-         "panel.ss")
+         "utils.rkt"
+         "base.rkt"
+         "panel.rkt")
 
 ;; INVARIANT: If a snip is selected, then no ancestor or
 ;;  descendant of the snip can be selected. Otherwise, the
diff --git a/collects/handin-client/info.rkt b/collects/handin-client/info.rkt
index 396d4a35be..ff3451bfed 100644
--- a/collects/handin-client/info.rkt
+++ b/collects/handin-client/info.rkt
@@ -9,7 +9,7 @@
 
 ;; The handin tool is disabled by default, uncomment these three lines to
 ;; enable it
-;(define drracket-tools      `("client-gui.ss"))
+;(define drracket-tools      `("client-gui.rkt"))
 ;(define drracket-tool-names `(,name))
 ;(define drracket-tool-icons `("icon.png"))
 ;; Modify the provided "icon.png" file to your school/lab/etc logo.
diff --git a/collects/help/bug-report.rkt b/collects/help/bug-report.rkt
index ec60725bbb..99e446453d 100644
--- a/collects/help/bug-report.rkt
+++ b/collects/help/bug-report.rkt
@@ -9,7 +9,7 @@
          net/uri-codec
          browser/htmltext
          "private/bug-report-controls.rkt"
-         "private/buginfo.ss"
+         "private/buginfo.rkt"
          "private/save-bug-report.rkt")
 
 (provide help-desk:report-bug
diff --git a/collects/help/help.rkt b/collects/help/help.rkt
index 039a343837..732e42037e 100644
--- a/collects/help/help.rkt
+++ b/collects/help/help.rkt
@@ -1,6 +1,6 @@
 #lang scheme/base
 
-(require "search.ss" scheme/cmdline scheme/list scheme/string
+(require "search.rkt" scheme/cmdline scheme/list scheme/string
          raco/command-name) 
 
 ;; Minimal command-line arguments, the query string can contain all
diff --git a/collects/help/private/bug-report-controls.rkt b/collects/help/private/bug-report-controls.rkt
index afcb38254c..7e222cce13 100644
--- a/collects/help/private/bug-report-controls.rkt
+++ b/collects/help/private/bug-report-controls.rkt
@@ -6,7 +6,7 @@
          string-constants/string-constant
          setup/dirs
          framework
-         "buginfo.ss"
+         "buginfo.rkt"
          "save-bug-report.rkt")
 
 (provide/contract
diff --git a/collects/honu/core/main.rkt b/collects/honu/core/main.rkt
index 63f65eeed2..1053417d15 100644
--- a/collects/honu/core/main.rkt
+++ b/collects/honu/core/main.rkt
@@ -5,7 +5,7 @@
 (require racket/class)
 
 (require "private/honu-typed-scheme.rkt"
-         "private/parse.ss"
+         "private/parse.rkt"
          (for-syntax "private/literals.rkt")
          (for-syntax "private/honu-typed-scheme.rkt")
          (for-syntax "private/parse.rkt")
@@ -20,7 +20,7 @@
          (for-syntax "private/more.rkt")
          (for-syntax "private/syntax.rkt")
          (for-syntax "private/macro.rkt")
-         "private/macro.ss")
+         "private/macro.rkt")
 
 (define-for-syntax (syntax-to-string stx)
   (format "original '~a' - ~a" (syntax->datum stx) (to-honu-string stx)))
diff --git a/collects/honu/core/private/honu-typed-scheme.rkt b/collects/honu/core/private/honu-typed-scheme.rkt
index 9f0f1c1a5c..22dab4aea3 100644
--- a/collects/honu/core/private/honu-typed-scheme.rkt
+++ b/collects/honu/core/private/honu-typed-scheme.rkt
@@ -20,7 +20,7 @@
          syntax/parse
          "literals.rkt"
          "debug.rkt"
-         ;; "typed-utils.ss"
+         ;; "typed-utils.rkt"
          )
 
 (require (for-meta 2 scheme/base "util.rkt"))
diff --git a/collects/honu/core/private/honu.rkt b/collects/honu/core/private/honu.rkt
index ff0b705ce5..a541a2a63d 100644
--- a/collects/honu/core/private/honu.rkt
+++ b/collects/honu/core/private/honu.rkt
@@ -9,9 +9,9 @@
              syntax/name
              syntax/parse
              scheme/pretty
-             "ops.ss"
-             "util.ss"
-             "contexts.ss"
+             "ops.rkt"
+             "util.rkt"
+             "contexts.rkt"
              ))
 
   (provide (all-defined-out))
diff --git a/collects/honu/core/private/macro.rkt b/collects/honu/core/private/macro.rkt
index 7e3cf142b6..dbf0c44cea 100644
--- a/collects/honu/core/private/macro.rkt
+++ b/collects/honu/core/private/macro.rkt
@@ -1,21 +1,21 @@
 #lang racket/base
 
-(require "honu-typed-scheme.ss"
+(require "honu-typed-scheme.rkt"
          "literals.rkt"
-         "parse.ss"
-         "syntax.ss"
+         "parse.rkt"
+         "syntax.rkt"
          syntax/parse
          (for-syntax macro-debugger/emit)
          (for-meta 2 macro-debugger/emit
                    racket/base)
          (for-meta -3
            (only-in "literals.rkt" (#%parens literal-parens)))
-         (for-syntax "debug.ss"
-                     "contexts.ss"
-                     "parse.ss"
-                     "syntax.ss"
+         (for-syntax "debug.rkt"
+                     "contexts.rkt"
+                     "parse.rkt"
+                     "syntax.rkt"
                      "literals.rkt"
-                     "honu-typed-scheme.ss"
+                     "honu-typed-scheme.rkt"
                      racket/base
                      syntax/parse
                      syntax/stx
diff --git a/collects/honu/core/private/parse.rkt b/collects/honu/core/private/parse.rkt
index f07a1b09de..fdfcf55fbd 100644
--- a/collects/honu/core/private/parse.rkt
+++ b/collects/honu/core/private/parse.rkt
@@ -1,14 +1,14 @@
 #lang racket/base
 
-(require "contexts.ss"
-         "util.ss"
-         (for-template "literals.ss"
-                       "language.ss"
-                       "syntax.ss"
+(require "contexts.rkt"
+         "util.rkt"
+         (for-template "literals.rkt"
+                       "language.rkt"
+                       "syntax.rkt"
                        racket/class)
          syntax/parse
          syntax/parse/experimental/splicing
-         "syntax.ss"
+         "syntax.rkt"
          "debug.rkt"
          (for-syntax syntax/parse
                      racket/base)
@@ -18,7 +18,7 @@
          syntax/name
          racket/match
          syntax/stx
-         (for-syntax "util.ss"
+         (for-syntax "util.rkt"
                      macro-debugger/emit)
          (for-syntax syntax/parse/private/runtime-report
                      syntax/parse/private/runtime
diff --git a/collects/htdp/hangman.rkt b/collects/htdp/hangman.rkt
index c9565bc6a0..ed5501c46b 100644
--- a/collects/htdp/hangman.rkt
+++ b/collects/htdp/hangman.rkt
@@ -1,7 +1,7 @@
 #lang mzscheme
-(require "error.ss"
-         "draw-sig.ss"
-         "big-draw.ss"
+(require "error.rkt"
+         "draw-sig.rkt"
+         "big-draw.rkt"
          mzlib/class
          mzlib/unit
          mzlib/etc
diff --git a/collects/htdp/image.rkt b/collects/htdp/image.rkt
index 92eccfa401..839bb1100d 100644
--- a/collects/htdp/image.rkt
+++ b/collects/htdp/image.rkt
@@ -3,7 +3,7 @@
 #|
 
 The test suite for this code is in
-plt/collects/tests/mzscheme/htdp-image.ss
+plt/collects/tests/mzscheme/htdp-image.rkt
 
 |#
 
@@ -12,10 +12,10 @@ plt/collects/tests/mzscheme/htdp-image.ss
          mzlib/class
          mrlib/cache-image-snip
          mzlib/math
-	 lang/prim
+         lang/prim
          lang/posn
          lang/private/imageeq
-         "error.ss")
+         "error.rkt")
 
 (provide-primitives
          image?
@@ -1084,7 +1084,7 @@ converting from the computer's coordinates, we get:
    0 0))
 
 (define (scene+line img x0 y0 x1 y1 c)
-  ;; img and c are checked via calls to add-line from image.ss
+  ;; img and c are checked via calls to add-line from image.rkt
   (check-arg 'scene+line (scene? img) "scene" "first" "plain image")
   (check-arg 'scene+line (real? x0) "number" "second" x0)
   (check-arg 'scene+line (real? y0) "number" "third" y0)
diff --git a/collects/htdp/info.rkt b/collects/htdp/info.rkt
index 61b3f7014e..c46ed5519e 100644
--- a/collects/htdp/info.rkt
+++ b/collects/htdp/info.rkt
@@ -2,10 +2,10 @@
 
 (define name "HtDP Teachpacks")
 (define compile-omit-paths
-  '("hangman-world.ss" "hangman-world-play.ss"
+  '("hangman-world.rkt" "hangman-world-play.rkt"
     ;; TEMPORARY DISABLE THESE FILES UNTIL FIXED
-    ;; "matrix.ss" "matrix-client.ss" "matrix-invisible.ss"
-    ;; "matrix-render-sig.ss" "matrix-sig.ss" "matrix-unit.ss"
+    ;; "matrix.rkt" "matrix-client.rkt" "matrix-invisible.rkt"
+    ;; "matrix-render-sig.rkt" "matrix-sig.rkt" "matrix-unit.rkt"
     "tests"))
 
 (define scribblings '(("htdp.scrbl")))
diff --git a/collects/htdp/master-play.rkt b/collects/htdp/master-play.rkt
index b6fa03ef81..0bfbc068d5 100644
--- a/collects/htdp/master-play.rkt
+++ b/collects/htdp/master-play.rkt
@@ -1,6 +1,6 @@
 #cs(module master-play mzscheme
   (require 
-   "master.ss"
+   "master.rkt"
    lang/prim)
   
   (provide go)
diff --git a/collects/htdp/matrix.rkt b/collects/htdp/matrix.rkt
index a289ca3737..b3bf8e3d7e 100644
--- a/collects/htdp/matrix.rkt
+++ b/collects/htdp/matrix.rkt
@@ -67,7 +67,7 @@ position structures returned by matrix-where?
     (define (visible? m) (and (object? m) (v? m)))
     (define visible-matrix v-m)
 
-    ;; the graphical stuff follows  .. it is code based on image.ss 
+    ;; the graphical stuff follows  .. it is code based on image.rkt
     ;; Matrix -> VisibleMatrix
     (define (make-visible M)
       (define S (matrix-render M))
@@ -161,7 +161,7 @@ position structures returned by matrix-where?
                     (loop (map cdr S-sizes))))))
       (values row-heights col-widths))
     
-    ;; --- copied from image.ss --- needs refactoring
+    ;; --- copied from image.rkt --- needs refactoring
     (define (get-text-size size string)
       (unless (thread-cell-ref cached-bdc-for-text-size)
         (let* ([bm (make-object bitmap% 1 1)]
diff --git a/collects/htdp/tests/arrow.rkt b/collects/htdp/tests/arrow.rkt
index acdd4db83b..aa12abb359 100644
--- a/collects/htdp/tests/arrow.rkt
+++ b/collects/htdp/tests/arrow.rkt
@@ -42,7 +42,7 @@
 ;; this creates the controller GUI
 (check-expect (control-left-right (make-posn 10 20) 10 move draw-it) true)
 
-; (load "tester.ss")
+; (load "tester.rkt")
 
 ; (test-error (control-left-right 'aa 10 move))
 
diff --git a/collects/htdp/tests/hangman1.rkt b/collects/htdp/tests/hangman1.rkt
index bf1f486c95..7546fc23de 100644
--- a/collects/htdp/tests/hangman1.rkt
+++ b/collects/htdp/tests/hangman1.rkt
@@ -3,7 +3,7 @@
 #reader(lib "htdp-beginner-reader.ss" "lang")((modname hangman1) (read-case-sensitive #t) (teachpacks ()) (htdp-settings #(#t constructor repeating-decimal #f #t none #f ())))
 (require htdp/hangman)
 
-; (load "tester.ss")
+; (load "tester.rkt")
 ;; by hand, Beginner for plain, Full for errors 
 
 
diff --git a/collects/htdp/tests/master.rkt b/collects/htdp/tests/master.rkt
index 37de0ec582..d8cb871a2a 100644
--- a/collects/htdp/tests/master.rkt
+++ b/collects/htdp/tests/master.rkt
@@ -3,7 +3,7 @@
 #reader(lib "htdp-beginner-reader.ss" "lang")((modname master) (read-case-sensitive #t) (teachpacks ()) (htdp-settings #(#t constructor repeating-decimal #f #t none #f ())))
 (require htdp/master)
 
-; (load "tester.ss")
+; (load "tester.rkt")
 
 ;; check-guess : color color color color -> symbol
 
diff --git a/collects/htdp/tests/matrix-test.rkt b/collects/htdp/tests/matrix-test.rkt
index 079afe5b3d..5c12c64b00 100644
--- a/collects/htdp/tests/matrix-test.rkt
+++ b/collects/htdp/tests/matrix-test.rkt
@@ -2,7 +2,7 @@
 ;; about the language level of this file in a form that our tools can easily process.
 #reader(lib "htdp-intermediate-lambda-reader.ss" "lang")((modname matrix-test) (read-case-sensitive #t) (teachpacks ()) (htdp-settings #(#t constructor repeating-decimal #f #t none #f ())))
 ;(require htdp/matrix-invisible)
-(require (lib "matrix.ss" "htdp"))
+(require (lib "matrix.rkt" "htdp"))
 
 (define r1 '((a00 a01 a02)
              (a10 a11 a12)))
diff --git a/collects/htdp/world.rkt b/collects/htdp/world.rkt
index 12a17c92f1..f4c0bc67af 100644
--- a/collects/htdp/world.rkt
+++ b/collects/htdp/world.rkt
@@ -24,7 +24,7 @@
 ;; Wed Apr 23 11:42:25 EDT 2008: fixed reverse bug in animation 
 ;; Thu Mar 20 17:15:54 EDT 2008: fixed place-image0, which used shrink off-by-1
 ;; Mon Sep 17 09:40:39 EDT 2007: run-simulation now allows recordings, too
-;; Mon Aug  6 19:50:30 EDT 2007: exporting both add-line from image.ss and scene+line 
+;; Mon Aug  6 19:50:30 EDT 2007: exporting both add-line from "image.rkt" and scene+line 
 ;; Fri May  4 18:05:33 EDT 2007: define-run-time-path 
 ;; Thu May  3 22:06:16 EDT 2007: scene # image; pasteboard% for text%
 ;; Sat Apr 28 13:31:02 EDT 2007: fixed the image and animated-gif thing, using Matthew's lib
@@ -60,7 +60,7 @@ Matthew
 ;; Sun Dec 09 23:17:41 EST 2006: add-line fixed so it cuts off lines before drawing
 ;; Mon Mar 27 10:29:28 EST 2006: integrated Felix's mouse events
 ;; Wed Jan 25 13:38:42 EST 2006: on-redraw: proc is now called on installation
-;; Tue Jan  3 11:17:50 EST 2006: changed add-line behavior in world.ss 
+;; Tue Jan  3 11:17:50 EST 2006: changed add-line behavior in "world.rkt"
 ;; Sat Dec 10 19:39:03 EST 2005: fixed name, changed interface to on-key-event
 ;; Fri Dec  9 21:39:03 EST 2005: remoevd (update ... produce ...); added on-redraw 
 ;; Thu Dec  1 17:03:03 EST 2005: fixed place-image; all coordinates okay now
diff --git a/collects/lang/htdp-advanced-reader.rkt b/collects/lang/htdp-advanced-reader.rkt
index f70e7bc8ca..c22827d692 100644
--- a/collects/lang/htdp-advanced-reader.rkt
+++ b/collects/lang/htdp-advanced-reader.rkt
@@ -1,7 +1,6 @@
 (module htdp-advanced-reader mzscheme
-  (require "htdp-reader.ss")
+  (require "htdp-reader.rkt")
   (provide (rename -read-syntax read-syntax)
            (rename -read read))
   (define -read-syntax (make-read-syntax '(lib "htdp-advanced.ss" "lang")))
   (define -read (make-read '(lib "htdp-advanced.ss" "lang"))))
-
diff --git a/collects/lang/htdp-advanced.rkt b/collects/lang/htdp-advanced.rkt
index 9d5d68065a..8b4cf60be1 100644
--- a/collects/lang/htdp-advanced.rkt
+++ b/collects/lang/htdp-advanced.rkt
@@ -1,15 +1,14 @@
-
 (module htdp-advanced scheme/base
-  (require "private/teach.ss"
-	   "private/teachprims.ss"
-	   "private/teach-module-begin.ss"
-	   mzlib/etc
-	   mzlib/list
-	   mzlib/pretty
-	   syntax/docprovide
+  (require "private/teach.rkt"
+           "private/teachprims.rkt"
+           "private/teach-module-begin.rkt"
+           mzlib/etc
+           mzlib/list
+           mzlib/pretty
+           syntax/docprovide
            scheme/promise
            test-engine/scheme-tests
-	   "posn.ss")
+           "posn.rkt")
 
   ;; syntax:
   (provide (rename-out
diff --git a/collects/lang/htdp-beginner-abbr-reader.rkt b/collects/lang/htdp-beginner-abbr-reader.rkt
index ea80a7bddb..6de88efa9d 100644
--- a/collects/lang/htdp-beginner-abbr-reader.rkt
+++ b/collects/lang/htdp-beginner-abbr-reader.rkt
@@ -1,7 +1,6 @@
 (module htdp-beginner-abbr-reader mzscheme
-  (require "htdp-reader.ss")
+  (require "htdp-reader.rkt")
   (provide (rename -read-syntax read-syntax)
            (rename -read read))
   (define -read-syntax (make-read-syntax '(lib "htdp-beginner-abbr.ss" "lang")))
   (define -read (make-read '(lib "htdp-beginner-abbr.ss" "lang"))))
-
diff --git a/collects/lang/htdp-beginner-abbr.rkt b/collects/lang/htdp-beginner-abbr.rkt
index 535c223984..79c94933f7 100644
--- a/collects/lang/htdp-beginner-abbr.rkt
+++ b/collects/lang/htdp-beginner-abbr.rkt
@@ -1,15 +1,14 @@
-
 (module htdp-beginner-abbr scheme/base
   (require mzlib/etc
-	   mzlib/list
-	   mzlib/math
-	   syntax/docprovide
+           mzlib/list
+           mzlib/math
+           syntax/docprovide
            test-engine/scheme-tests)
 
   ;; Implements the forms:
-  (require "private/teach.ss"
-	   "private/teachprims.ss"
-	   "private/teach-module-begin.ss")
+  (require "private/teach.rkt"
+           "private/teachprims.rkt"
+           "private/teach-module-begin.rkt")
 
   ;; syntax:
   (provide (rename-out
diff --git a/collects/lang/htdp-beginner-reader.rkt b/collects/lang/htdp-beginner-reader.rkt
index 79c9dd9fd2..991fcce1e7 100644
--- a/collects/lang/htdp-beginner-reader.rkt
+++ b/collects/lang/htdp-beginner-reader.rkt
@@ -1,7 +1,6 @@
 (module htdp-beginner-reader mzscheme
-  (require "htdp-reader.ss")
+  (require "htdp-reader.rkt")
   (provide (rename -read-syntax read-syntax)
            (rename -read read))
   (define -read-syntax (make-read-syntax '(lib "htdp-beginner.ss" "lang")))
   (define -read (make-read '(lib "htdp-beginner.ss" "lang"))))
-
diff --git a/collects/lang/htdp-beginner.rkt b/collects/lang/htdp-beginner.rkt
index 350e0bbf08..a25680d4c9 100644
--- a/collects/lang/htdp-beginner.rkt
+++ b/collects/lang/htdp-beginner.rkt
@@ -1,17 +1,16 @@
-
 ;; Implements the Beginner Scheme language, at least in terms of the
 ;; forms and procedures. The reader-level aspects of the language
 ;; (e.g., case-sensitivity) are not implemented here.
 
 (module htdp-beginner scheme/base
   (require mzlib/etc
-	   mzlib/list
-	   syntax/docprovide
+           mzlib/list
+           syntax/docprovide
            (for-syntax scheme/base))
 
   ;; Implements the forms:
-  (require "private/teach.ss"
-	   "private/teach-module-begin.ss"
+  (require "private/teach.rkt"
+           "private/teach-module-begin.rkt"
            test-engine/scheme-tests)
 
   ;; syntax:
diff --git a/collects/lang/htdp-intermediate-lambda-reader.rkt b/collects/lang/htdp-intermediate-lambda-reader.rkt
index cbc47bc039..40cd89d999 100644
--- a/collects/lang/htdp-intermediate-lambda-reader.rkt
+++ b/collects/lang/htdp-intermediate-lambda-reader.rkt
@@ -1,7 +1,6 @@
 (module htdp-intermediate-lambda-reader mzscheme
-  (require "htdp-reader.ss")
+  (require "htdp-reader.rkt")
   (provide (rename -read-syntax read-syntax)
            (rename -read read))
   (define -read-syntax (make-read-syntax '(lib "htdp-intermediate-lambda.ss" "lang")))
   (define -read (make-read '(lib "htdp-intermediate-lambda.ss" "lang"))))
-
diff --git a/collects/lang/htdp-intermediate-lambda.rkt b/collects/lang/htdp-intermediate-lambda.rkt
index 7a1acb3200..5bb4c3ba5a 100644
--- a/collects/lang/htdp-intermediate-lambda.rkt
+++ b/collects/lang/htdp-intermediate-lambda.rkt
@@ -1,12 +1,11 @@
-
 (module htdp-intermediate-lambda scheme/base
-  (require "private/teach.ss"
-	   "private/teach-module-begin.ss"
-	   mzlib/etc
-	   mzlib/list
-	   syntax/docprovide
+  (require "private/teach.rkt"
+           "private/teach-module-begin.rkt"
+           mzlib/etc
+           mzlib/list
+           syntax/docprovide
            test-engine/scheme-tests)
-  
+
   ;; syntax:
   (provide (rename-out
             [intermediate-lambda-define define]
diff --git a/collects/lang/htdp-intermediate-reader.rkt b/collects/lang/htdp-intermediate-reader.rkt
index 11d65ac66c..c1347347a3 100644
--- a/collects/lang/htdp-intermediate-reader.rkt
+++ b/collects/lang/htdp-intermediate-reader.rkt
@@ -4,4 +4,3 @@
            (rename -read read))
   (define -read-syntax (make-read-syntax '(lib "htdp-intermediate.ss" "lang")))
   (define -read (make-read '(lib "htdp-intermediate.ss" "lang"))))
-
diff --git a/collects/lang/htdp-intermediate.rkt b/collects/lang/htdp-intermediate.rkt
index 8c9c806b34..655f794473 100644
--- a/collects/lang/htdp-intermediate.rkt
+++ b/collects/lang/htdp-intermediate.rkt
@@ -1,11 +1,10 @@
-
 (module htdp-intermediate scheme/base
-  (require "private/teach.ss"
-           "private/teachprims.ss"
-	   "private/teach-module-begin.ss"
-	   mzlib/etc
-	   mzlib/list
-	   syntax/docprovide
+  (require "private/teach.rkt"
+           "private/teachprims.rkt"
+           "private/teach-module-begin.rkt"
+           mzlib/etc
+           mzlib/list
+           syntax/docprovide
            test-engine/scheme-tests)
 
   ;; syntax:
diff --git a/collects/lang/htdp-langs.rkt b/collects/lang/htdp-langs.rkt
index cb4b0cc133..5f4a3537b0 100644
--- a/collects/lang/htdp-langs.rkt
+++ b/collects/lang/htdp-langs.rkt
@@ -20,24 +20,24 @@
          wxme/wxme
          setup/dirs
          test-engine/racket-tests
-         
+
          ;; this module is shared between the drscheme's namespace (so loaded here) 
          ;; and the user's namespace in the teaching languages
-         "private/set-result.ss"
+         "private/set-result.rkt"
 
          "private/continuation-mark-key.rkt"
 
-         "stepper-language-interface.ss"           
-         "debugger-language-interface.ss"
-         "run-teaching-program.ss"
+         "stepper-language-interface.rkt"
+         "debugger-language-interface.rkt"
+         "run-teaching-program.rkt"
          stepper/private/shared
-         
+
          (only-in test-engine/scheme-gui make-formatter)
-         (only-in test-engine/scheme-tests 
-		  scheme-test-data error-handler test-format test-execute display-results
-		  build-test-engine)
+         (only-in test-engine/scheme-tests
+                  scheme-test-data error-handler test-format test-execute display-results
+                  build-test-engine)
          (lib "test-engine/test-display.scm")
-	 deinprogramm/signature/signature
+         deinprogramm/signature/signature
          )
   
   
@@ -518,7 +518,7 @@
                        (string-append no-ext-name ".scm")]
                       [(file-exists? no-ext-name)
                        no-ext-name]
-                      [else (error 'htdp-lang.ss "could not find language filename ~s" no-ext-name)])]
+                      [else (error 'htdp-lang.rkt "could not find language filename ~s" no-ext-name)])]
                    [base-dir (let-values ([(base _1 _2) (split-path full-name)]) base)]
                    [stx
                     (call-with-input-file full-name
diff --git a/collects/lang/imageeq.rkt b/collects/lang/imageeq.rkt
index 4e4e5b51fe..786bb11bad 100644
--- a/collects/lang/imageeq.rkt
+++ b/collects/lang/imageeq.rkt
@@ -7,7 +7,7 @@
   (define tried? #f)
 
   ;; This macro is used once to export all functions
-  ;;  from "private/image.ss":
+  ;;  from "private/image.rkt":
   (define-syntax (re-export stx)
     (syntax-case stx ()
       [(_ (id . impl) ...) 
diff --git a/collects/lang/info.rkt b/collects/lang/info.rkt
index f6eaf6a761..58ca64b515 100644
--- a/collects/lang/info.rkt
+++ b/collects/lang/info.rkt
@@ -3,13 +3,13 @@
 (require string-constants)
 
 (define name "HtDP Languages")
-(define tools (list "htdp-langs.ss"))
+(define tools (list "htdp-langs.rkt"))
 (define tool-icons (list '("htdp-icon.gif" "icons")))
 (define tool-names (list "How to Design Programs"))
 (define tool-urls (list "http://www.htdp.org/"))
 
 (define compile-omit-paths
-  '("test-error.ss"))
+  '("test-error.rkt"))
 
 (define textbook-pls
   (list (list '("htdp-icon.gif" "icons")
diff --git a/collects/lang/plt-pretty-big-text.rkt b/collects/lang/plt-pretty-big-text.rkt
index 0057d8c5fb..0877dc795d 100644
--- a/collects/lang/plt-pretty-big-text.rkt
+++ b/collects/lang/plt-pretty-big-text.rkt
@@ -1,32 +1,31 @@
-
 (module plt-pretty-big-text mzscheme
   (require mzlib/etc
-	   mzlib/file
-	   mzlib/list
-	   mzlib/class
-	   mzlib/unit
-	   mzlib/include
-	   mzlib/defmacro
-	   mzlib/pretty
-	   mzlib/string
-	   mzlib/thread
-	   mzlib/math
-	   mzlib/match
-	   mzlib/shared
-	   "posn.ss")
+           mzlib/file
+           mzlib/list
+           mzlib/class
+           mzlib/unit
+           mzlib/include
+           mzlib/defmacro
+           mzlib/pretty
+           mzlib/string
+           mzlib/thread
+           mzlib/math
+           mzlib/match
+           mzlib/shared
+           "posn.rkt")
 
   (provide (all-from mzscheme)
-	   (all-from mzlib/etc)
-	   (all-from mzlib/file)
-	   (all-from mzlib/list)
-	   (all-from mzlib/class)
-	   (all-from mzlib/unit)
-	   (all-from mzlib/include)
-	   (all-from mzlib/defmacro)
-	   (all-from mzlib/pretty)
-	   (all-from mzlib/string)
-	   (all-from mzlib/thread)
-	   (all-from mzlib/math)
-	   (all-from mzlib/match)
-	   (all-from mzlib/shared)
-	   (all-from "posn.ss")))
+           (all-from mzlib/etc)
+           (all-from mzlib/file)
+           (all-from mzlib/list)
+           (all-from mzlib/class)
+           (all-from mzlib/unit)
+           (all-from mzlib/include)
+           (all-from mzlib/defmacro)
+           (all-from mzlib/pretty)
+           (all-from mzlib/string)
+           (all-from mzlib/thread)
+           (all-from mzlib/math)
+           (all-from mzlib/match)
+           (all-from mzlib/shared)
+           (all-from "posn.rkt")))
diff --git a/collects/lang/plt-pretty-big.rkt b/collects/lang/plt-pretty-big.rkt
index 2191491c7a..ceefde078a 100644
--- a/collects/lang/plt-pretty-big.rkt
+++ b/collects/lang/plt-pretty-big.rkt
@@ -1,9 +1,6 @@
+(module plt-pretty-big "plt-pretty-big-text.rkt"
+  (require mred "private/imageeq.rkt")
 
-(module plt-pretty-big "plt-pretty-big-text.ss"
-  (require mred
-           "private/imageeq.ss")
-
-  (provide (all-from "plt-pretty-big-text.ss")
-	   (all-from mred)
-           (all-from "private/imageeq.ss")))
-
+  (provide (all-from "plt-pretty-big-text.rkt")
+           (all-from mred)
+           (all-from "private/imageeq.rkt")))
diff --git a/collects/lang/prim.rkt b/collects/lang/prim.rkt
index 7c6ea5995e..a5fce8bc02 100644
--- a/collects/lang/prim.rkt
+++ b/collects/lang/prim.rkt
@@ -1,4 +1,3 @@
-
 ;; Provides `define-primitive' and `define-higher-order-primitive'
 ;; for use in teachpacks for Beginner, especially those that
 ;; define a primitive operator that consumes a procedure.
@@ -6,9 +5,9 @@
 
 (module prim mzscheme
   (require lang/error
-	   (rename lang/htdp-beginner beginner-app #%app))
+           (rename lang/htdp-beginner beginner-app #%app))
   
-  (require-for-syntax (prefix fo: "private/firstorder.ss")
+  (require-for-syntax (prefix fo: "private/firstorder.rkt")
                       stepper/private/shared)
   
   (provide define-primitive
diff --git a/collects/lang/private/advanced-funs.rkt b/collects/lang/private/advanced-funs.rkt
index 8b68af3817..28adf3142f 100644
--- a/collects/lang/private/advanced-funs.rkt
+++ b/collects/lang/private/advanced-funs.rkt
@@ -1,14 +1,14 @@
 (module advanced-funs scheme/base
-  (require "teachprims.ss"
+  (require "teachprims.rkt"
            mzlib/etc
            mzlib/list
            mzlib/pretty
            syntax/docprovide
            scheme/promise
            scheme/port
-           "../posn.ss"
+           "../posn.rkt"
            (for-syntax scheme/base))
-  
+
   (define pp
     (let ([pretty-print (lambda (v)
                           (pretty-write v))])
diff --git a/collects/lang/private/and-or-map.rkt b/collects/lang/private/and-or-map.rkt
index a2bb7dcb16..f3436980d3 100644
--- a/collects/lang/private/and-or-map.rkt
+++ b/collects/lang/private/and-or-map.rkt
@@ -3,7 +3,7 @@
 ;; ---------------------------------------------------------------------------------------------------
 ;; define higher-order primitives that consume boolean-valued functions 
 
-(require "teachprims.ss" "teach.ss")
+(require "teachprims.rkt" "teach.rkt")
 
 (provide intermediate-andmap intermediate-ormap intermediate-filter 
          intermediate-quicksort intermediate-sort)
diff --git a/collects/lang/private/beginner-funs.rkt b/collects/lang/private/beginner-funs.rkt
index c2a2fa12df..d08f7574d4 100644
--- a/collects/lang/private/beginner-funs.rkt
+++ b/collects/lang/private/beginner-funs.rkt
@@ -1,11 +1,10 @@
-
 (module beginner-funs scheme
   (require mzlib/etc mzlib/list mzlib/math syntax/docprovide)
 
   ;; Implements the procedures:
-  (require "teachprims.ss"
-	   "../posn.ss"
-	   "../imageeq.ss")
+  (require "teachprims.rkt"
+           "../posn.rkt"
+           "../imageeq.rkt")
 
   ;; procedures with documentation:
   (provide-and-document
diff --git a/collects/lang/private/intermediate-funs.rkt b/collects/lang/private/intermediate-funs.rkt
index 9771adbaac..1a3c52ec7a 100644
--- a/collects/lang/private/intermediate-funs.rkt
+++ b/collects/lang/private/intermediate-funs.rkt
@@ -1,8 +1,8 @@
 (module intermediate-funs scheme/base
-  (require "teachprims.ss" "and-or-map.ss"
-	   mzlib/etc
-	   scheme/list
-	   syntax/docprovide
+  (require "teachprims.rkt" "and-or-map.rkt"
+           mzlib/etc
+           scheme/list
+           syntax/docprovide
            (for-syntax scheme/base))
 
   (provide-and-document
diff --git a/collects/lang/private/teach-module-begin.rkt b/collects/lang/private/teach-module-begin.rkt
index 35d559e17c..2741142f3e 100644
--- a/collects/lang/private/teach-module-begin.rkt
+++ b/collects/lang/private/teach-module-begin.rkt
@@ -3,18 +3,18 @@
 ; Once upon a time, there were three different variants.  Preserve the
 ; ability to do this.
 (provide (rename-out (module-begin beginner-module-begin)
-		     (module-begin intermediate-module-begin)
-		     (module-begin advanced-module-begin)))
+                     (module-begin intermediate-module-begin)
+                     (module-begin advanced-module-begin)))
 
 (require deinprogramm/signature/signature
-	 lang/private/signature-syntax)
+         lang/private/signature-syntax)
 
 (require (for-syntax scheme/base)
-	 (for-syntax racket/list)
-	 (for-syntax syntax/boundmap)
-	 (for-syntax syntax/kerncase))
+         (for-syntax racket/list)
+         (for-syntax syntax/boundmap)
+         (for-syntax syntax/kerncase))
 
-(require (for-syntax "firstorder.ss"))
+(require (for-syntax "firstorder.rkt"))
 
 (define-syntax (print-results stx)
   (syntax-case stx ()
diff --git a/collects/lang/private/teach-shared.rkt b/collects/lang/private/teach-shared.rkt
index 79de7212bb..01508b2f0b 100644
--- a/collects/lang/private/teach-shared.rkt
+++ b/collects/lang/private/teach-shared.rkt
@@ -10,11 +10,11 @@
 
 (require (for-template
           scheme/base
-          (only-in "teachprims.ss" [advanced-cons the-cons])))
+          (only-in "teachprims.rkt" [advanced-cons the-cons])))
 
 (define shared/proc
   (lambda (stx make-check-cdr undefined-expr)
     (with-syntax ([undefined undefined-expr])
       ;; Include the implementation.
-      ;; See private/shared-body.ss.
-      (include (lib "mzlib/private/shared-body.ss")))))
+      ;; See private/shared-body.rkt.
+      (include (lib "mzlib/private/shared-body.rkt")))))
diff --git a/collects/lang/private/teach.rkt b/collects/lang/private/teach.rkt
index a0fb81bd30..07f30bc655 100644
--- a/collects/lang/private/teach.rkt
+++ b/collects/lang/private/teach.rkt
@@ -1,4 +1,3 @@
-
 ;; Implements the syntactic forms for the HtDP teaching languages. The
 ;; reader-level aspects of the language (e.g., case-sensitivity) are
 ;; not implemented here, and the procedures are in a separate
@@ -35,37 +34,37 @@
 
 (module teach mzscheme
   (require mzlib/etc
-	   mzlib/list
-	   mzlib/math
-	   mzlib/pconvert-prop
+           mzlib/list
+           mzlib/math
+           mzlib/pconvert-prop
            scheme/match
-           "set-result.ss"
+           "set-result.rkt"
            (only racket/base define-struct)
-	   racket/struct-info
-	   deinprogramm/signature/signature-english
-	   (all-except deinprogramm/signature/signature signature-violation)
-	   (all-except lang/private/signature-syntax property)
-	   (rename lang/private/signature-syntax signature:property property)
-	   (all-except deinprogramm/quickcheck/quickcheck property)
-	   (rename deinprogramm/quickcheck/quickcheck quickcheck:property property)
-	   test-engine/racket-tests
-	   scheme/class
+           racket/struct-info
+           deinprogramm/signature/signature-english
+           (all-except deinprogramm/signature/signature signature-violation)
+           (all-except lang/private/signature-syntax property)
+           (rename lang/private/signature-syntax signature:property property)
+           (all-except deinprogramm/quickcheck/quickcheck property)
+           (rename deinprogramm/quickcheck/quickcheck quickcheck:property property)
+           test-engine/racket-tests
+           scheme/class
            "../posn.rkt"
-	   (only lang/private/teachprims
+           (only lang/private/teachprims
                  beginner-equal? beginner-equal~? teach-equal?
                  advanced-cons advanced-list*))
-  (require-for-syntax "teachhelp.ss"
-                      "teach-shared.ss"
-		      syntax/kerncase
-		      syntax/stx
-		      syntax/struct
-		      syntax/context
-		      mzlib/include
-		      scheme/list
-		      (rename racket/base racket:define-struct define-struct)
-		      (only racket/base syntax->datum datum->syntax)
+  (require-for-syntax "teachhelp.rkt"
+                      "teach-shared.rkt"
+                      syntax/kerncase
+                      syntax/stx
+                      syntax/struct
+                      syntax/context
+                      mzlib/include
+                      scheme/list
+                      (rename racket/base racket:define-struct define-struct)
+                      (only racket/base syntax->datum datum->syntax)
                       (rename racket/base kw-app #%app)
-		      racket/struct-info
+                      racket/struct-info
                       stepper/private/shared
                       test-engine/racket-tests)
 
@@ -107,8 +106,8 @@
       (error who "cannot redefine name: ~a" (syntax-e id))))
 
   ;; For quasiquote and shared:
-  (require (rename "teachprims.ss" the-cons advanced-cons))
-  (require (only   "teachprims.ss" cyclic-list?))
+  (require (rename "teachprims.rkt" the-cons advanced-cons))
+  (require (only   "teachprims.rkt" cyclic-list?))
 
   ;; Referenced to ensure that evaluating `lambda' always
   ;; produces a new closure (instead of using a closure
@@ -2756,7 +2755,7 @@
     ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
     ;; We do all the initial syntax checks, and otherwise
-    ;; let "shared-body.ss" implement the form.
+    ;; let "shared-body.rkt" implement the form.
 
     (define advanced-shared/proc
       (lambda (stx)
diff --git a/collects/lang/private/teachhelp.rkt b/collects/lang/private/teachhelp.rkt
index 87ed59b2fb..e75aeda34d 100644
--- a/collects/lang/private/teachhelp.rkt
+++ b/collects/lang/private/teachhelp.rkt
@@ -1,6 +1,5 @@
-
 (module teachhelp mzscheme
-  (require "firstorder.ss"
+  (require "firstorder.rkt"
            stepper/private/shared)
 
   (require-for-syntax stepper/private/shared)
diff --git a/collects/lang/private/teachprims.rkt b/collects/lang/private/teachprims.rkt
index dc4cf35eef..9280a3c2cc 100644
--- a/collects/lang/private/teachprims.rkt
+++ b/collects/lang/private/teachprims.rkt
@@ -1,11 +1,11 @@
 #lang scheme 
 
 #| tests are at plt/collects/tests/mzscheme/
-collects/tests/mzscheme/beginner.ss
-                    .../beginner-abbr.ss
-                    .../intermediate.ss
-                    .../intermediate-lambda.ss
-                    .../advanced.ss
+collects/tests/mzscheme/beginner.rkt
+                    .../beginner-abbr.rkt
+                    .../intermediate.rkt
+                    .../intermediate-lambda.rkt
+                    .../advanced.rkt
 
 Each one has to run separately, since they mangle the top-level
 namespace.
diff --git a/collects/lang/r5rs.rkt b/collects/lang/r5rs.rkt
index 8429570c0f..bd538fc8ec 100644
--- a/collects/lang/r5rs.rkt
+++ b/collects/lang/r5rs.rkt
@@ -1,4 +1,4 @@
-;; This module provides R5RS Scheme, which is defined in "r5rs/main.ss".
+;; This module provides R5RS Scheme, which is defined in "r5rs/main.rkt".
 ;; This file is here only as a stub for backward compatibility; use one
 ;;   r5rs
 ;; instead.
diff --git a/collects/lang/run-teaching-program.rkt b/collects/lang/run-teaching-program.rkt
index b54a069ec1..98f0291551 100644
--- a/collects/lang/run-teaching-program.rkt
+++ b/collects/lang/run-teaching-program.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 
-(require "stepper-language-interface.ss"           
-         "debugger-language-interface.ss"
+(require "stepper-language-interface.rkt"
+         "debugger-language-interface.rkt"
          stepper/private/shared
          scheme/class
          scheme/contract
diff --git a/collects/launcher/launcher-unit.rkt b/collects/launcher/launcher-unit.rkt
index 5b22f289e2..0a4ad7668b 100644
--- a/collects/launcher/launcher-unit.rkt
+++ b/collects/launcher/launcher-unit.rkt
@@ -9,7 +9,7 @@
          setup/dirs
          setup/variant
 
-         "launcher-sig.ss"
+         "launcher-sig.rkt"
 
          compiler/private/winutf16)
 
@@ -359,7 +359,7 @@
         (display header)
         (newline)
         ;; comments needed to rehack launchers when paths change
-        ;; (see setup/unixstyle-install.ss)
+        ;; (see setup/unixstyle-install.rkt)
         (display "# {{{ bindir\n")
         (display dir-finder)
         (display "# }}} bindir\n")
diff --git a/collects/launcher/launcher.rkt b/collects/launcher/launcher.rkt
index dd203948f5..e557157d56 100644
--- a/collects/launcher/launcher.rkt
+++ b/collects/launcher/launcher.rkt
@@ -1,8 +1,8 @@
 #lang scheme/base
 
 (require scheme/unit
-         "launcher-sig.ss"
-         "launcher-unit.ss")
+         "launcher-sig.rkt"
+         "launcher-unit.rkt")
 
 (define-values/invoke-unit/infer launcher@)
 
diff --git a/collects/launcher/main.rkt b/collects/launcher/main.rkt
index 4aecff9584..e113c15ffc 100644
--- a/collects/launcher/main.rkt
+++ b/collects/launcher/main.rkt
@@ -1,4 +1,4 @@
 #lang scheme/base
 
-(require "launcher.ss")
-(provide (all-from-out "launcher.ss"))
+(require "launcher.rkt")
+(provide (all-from-out "launcher.rkt"))
diff --git a/collects/lazy/info.rkt b/collects/lazy/info.rkt
index deb2be6d5c..48c3f462ac 100644
--- a/collects/lazy/info.rkt
+++ b/collects/lazy/info.rkt
@@ -9,7 +9,7 @@
 
 ;(require string-constants)
 ;(define name "Lazy Scheme")
-;(define drscheme-language-modules '(("lazy.ss" "lazy")))
+;(define drscheme-language-modules '(("lazy.rkt" "lazy")))
 ;(define drscheme-language-positions
 ;  `((,(string-constant experimental-languages) "Lazy Racket")))
 ;(define drscheme-language-numbers '((1000 -500)))
diff --git a/collects/lazy/lazy.rkt b/collects/lazy/lazy.rkt
index d955723559..c3c7d003c1 100644
--- a/collects/lazy/lazy.rkt
+++ b/collects/lazy/lazy.rkt
@@ -9,7 +9,7 @@
   ;; --------------------------------------------------------------------------
   ;; Syntax utilities
 
-  ;; taken & modified from swindle/misc.ss
+  ;; taken & modified from swindle/misc.rkt
   (provide defsubst) ; useful utility
   (define-syntax (defsubst-process stx)
     (syntax-case stx ()
@@ -45,7 +45,7 @@
   ;; --------------------------------------------------------------------------
   ;; Delay/force etc
 
-  (require "force.ss")
+  (require "force.rkt")
 
   (provide ~)
 
diff --git a/collects/lazy/main.rkt b/collects/lazy/main.rkt
index 51d6ed5f5d..a857a3d984 100644
--- a/collects/lazy/main.rkt
+++ b/collects/lazy/main.rkt
@@ -1,2 +1,2 @@
-(module main "lazy.ss"
-  (provide (all-from "lazy.ss")))
+(module main "lazy.rkt"
+  (provide (all-from "lazy.rkt")))
diff --git a/collects/make/collection-unit.rkt b/collects/make/collection-unit.rkt
index e4daf3eee2..084fe58bfb 100644
--- a/collects/make/collection-unit.rkt
+++ b/collects/make/collection-unit.rkt
@@ -3,8 +3,8 @@
 (require mzlib/unit
          mzlib/list
          mzlib/file
-         "collection-sig.ss"
-         "make-sig.ss"
+         "collection-sig.rkt"
+         "make-sig.rkt"
          compiler/sig
          dynext/file-sig)
 
diff --git a/collects/make/collection.rkt b/collects/make/collection.rkt
index fceb40b9c1..fc3627c9f1 100644
--- a/collects/make/collection.rkt
+++ b/collects/make/collection.rkt
@@ -7,10 +7,10 @@
          compiler/compiler
          compiler/option)
 
-(require "make-sig.ss"
-         "make.ss"
-         "collection-sig.ss"
-         "collection-unit.ss")
+(require "make-sig.rkt"
+         "make.rkt"
+         "collection-sig.rkt"
+         "collection-unit.rkt")
 
 (define-values/invoke-unit/infer make:collection@)
 
diff --git a/collects/make/main.rkt b/collects/make/main.rkt
index 4d04b65641..0806adc91f 100644
--- a/collects/make/main.rkt
+++ b/collects/make/main.rkt
@@ -1,4 +1,4 @@
 #lang scheme/base
 
-(require "make.ss")
-(provide (all-from-out "make.ss"))
+(require "make.rkt")
+(provide (all-from-out "make.rkt"))
diff --git a/collects/make/make-unit.rkt b/collects/make/make-unit.rkt
index 12338e6c2a..5485140c49 100644
--- a/collects/make/make-unit.rkt
+++ b/collects/make/make-unit.rkt
@@ -1,6 +1,6 @@
 #lang scheme/unit
 
-(require "make-sig.ss")
+(require "make-sig.rkt")
 
 (import)
 (export make^)
diff --git a/collects/make/make.rkt b/collects/make/make.rkt
index b3314f40c8..e321e05b48 100644
--- a/collects/make/make.rkt
+++ b/collects/make/make.rkt
@@ -1,8 +1,8 @@
 #lang mzscheme
 
 (require mzlib/unit
-         "make-sig.ss"
-         "make-unit.ss")
+         "make-sig.rkt"
+         "make-unit.rkt")
 
 (define-values/invoke-unit/infer make@)
 
diff --git a/collects/meta/check-dists.rkt b/collects/meta/check-dists.rkt
index 4726d845b7..2c33c66b61 100644
--- a/collects/meta/check-dists.rkt
+++ b/collects/meta/check-dists.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
-(require "checker.ss"
-         "specs.ss"
-         "dist-specs.ss")
+(require "checker.rkt"
+         "specs.rkt"
+         "dist-specs.rkt")
 
 (parameterize ([*specs* #f]
                [current-namespace (namespace-anchor->namespace checker-namespace-anchor)])
diff --git a/collects/meta/checker.rkt b/collects/meta/checker.rkt
index 9d17a223f8..ae348dafd0 100644
--- a/collects/meta/checker.rkt
+++ b/collects/meta/checker.rkt
@@ -1,5 +1,5 @@
-;; Shared dependency-checking infrastructure, used by "check-dists.ss"
-;; and by bundle script
+;; Shared dependency-checking infrastructure, used by "check-dists.rkt"
+;; and by the bundle script
 
 #lang scheme/base
 
@@ -7,8 +7,8 @@
          scheme/list ; for use in specs too
          (for-syntax scheme/base) ; for runtime-path
          (except-in scheme/mpair mappend)
-         (only-in (lib "process.ss") system)
-         "specs.ss")
+         (only-in mzlib/process system)
+         "specs.rkt")
 
 (define cd current-directory)
 
@@ -516,8 +516,8 @@
       (cond [(null? deps) #t]
             [(equal? (car deps) last-dep) (loop files (cdr deps) last-dep)]
             [(or (null? files) (string<? (car deps) (car files)))
-             ;; Exception: foo.ss might be satisified by a platform dependent
-             ;; compiled/foo_ss.zo (need to exist in all platform dependent
+             ;; Exception: foo.rkt might be satisified by a platform dependent
+             ;; compiled/foo_rkt.zo (need to exist in all platform dependent
              ;; trees).  No need to optimize since this happens very
              ;; infrequently.
              (let ([dep (regexp-replace #rx"/([^/]+)\\.([^/]+)$" (car deps)
diff --git a/collects/meta/spec-lang.rkt b/collects/meta/spec-lang.rkt
index 1fe7b6a2bd..107da410ec 100644
--- a/collects/meta/spec-lang.rkt
+++ b/collects/meta/spec-lang.rkt
@@ -1,5 +1,5 @@
 #lang scheme/base
-(require "specs.ss")
+(require "specs.rkt")
 
 (provide (rename-out [module-begin #%module-begin]))
 
diff --git a/collects/meta/tree/file-tree.rkt b/collects/meta/tree/file-tree.rkt
index 48bf7316a1..5cdd17a8ee 100644
--- a/collects/meta/tree/file-tree.rkt
+++ b/collects/meta/tree/file-tree.rkt
@@ -2,7 +2,7 @@
 
 (provide get-file-tree get-plt-file-tree)
 
-(require "tree.ss" setup/dirs)
+(require "tree.rkt" setup/dirs)
 
 ;; ----------------------------------------------------------------------------
 ;; Reading a tree from a directory
diff --git a/collects/meta/tree/svn-tree.rkt b/collects/meta/tree/svn-tree.rkt
index 42b450ffc9..f71f0b4604 100644
--- a/collects/meta/tree/svn-tree.rkt
+++ b/collects/meta/tree/svn-tree.rkt
@@ -2,7 +2,7 @@
 
 (provide get-svn-tree get-plt-svn-tree)
 
-(require "tree.ss" scheme/system scheme/match xml)
+(require "tree.rkt" scheme/system scheme/match xml)
 
 (define svn-exe (find-executable-path "svn"))
 (define (svn . args)
diff --git a/collects/meta/tree/tests.rkt b/collects/meta/tree/tests.rkt
index 953479ae5b..e5fbd9c3a1 100644
--- a/collects/meta/tree/tests.rkt
+++ b/collects/meta/tree/tests.rkt
@@ -140,37 +140,37 @@
                     entries
                     format
                     (prop-base
-                     base-render.ss.svn-base
-                     base.ss.svn-base
-                     basic.ss.svn-base
-                     bnf.ss.svn-base
-                     comment-reader.ss.svn-base
-                     config.ss.svn-base
-                     core.ss.svn-base
-                     decode-struct.ss.svn-base
-                     decode.ss.svn-base
+                     base-render.rkt.svn-base
+                     base.rkt.svn-base
+                     basic.rkt.svn-base
+                     bnf.rkt.svn-base
+                     comment-reader.rkt.svn-base
+                     config.rkt.svn-base
+                     core.rkt.svn-base
+                     decode-struct.rkt.svn-base
+                     decode.rkt.svn-base
                      doc.txt.svn-base
-                     doclang.ss.svn-base
-                     eval.ss.svn-base
-                     extract.ss.svn-base
-                     html-properties.ss.svn-base
-                     html-render.ss.svn-base
-                     info.ss.svn-base
-                     latex-properties.ss.svn-base
-                     latex-render.ss.svn-base
-                     lp-include.ss.svn-base
-                     lp.ss.svn-base
+                     doclang.rkt.svn-base
+                     eval.rkt.svn-base
+                     extract.rkt.svn-base
+                     html-properties.rkt.svn-base
+                     html-render.rkt.svn-base
+                     info.rkt.svn-base
+                     latex-properties.rkt.svn-base
+                     latex-render.rkt.svn-base
+                     lp-include.rkt.svn-base
+                     lp.rkt.svn-base
                      manual-prefix.tex.svn-base
-                     manual-struct.ss.svn-base
+                     manual-struct.rkt.svn-base
                      manual-style.tex.svn-base
-                     manual.ss.svn-base
-                     pdf-render.ss.svn-base
-                     provide-doc-transform.ss.svn-base
-                     reader.ss.svn-base
-                     render-struct.ss.svn-base
-                     run.ss.svn-base
+                     manual.rkt.svn-base
+                     pdf-render.rkt.svn-base
+                     provide-doc-transform.rkt.svn-base
+                     reader.rkt.svn-base
+                     render-struct.rkt.svn-base
+                     run.rkt.svn-base
                      scheme.css.svn-base
-                     scheme.ss.svn-base
+                     scheme.rkt.svn-base
                      scheme.tex.svn-base
                      scribble-common.js.svn-base
                      scribble-prefix.html.svn-base
@@ -179,47 +179,47 @@
                      scribble-style.tex.svn-base
                      scribble.css.svn-base
                      scribble.tex.svn-base
-                     search.ss.svn-base
-                     sigplan.ss.svn-base
-                     srcdoc.ss.svn-base
-                     struct.ss.svn-base
-                     text-render.ss.svn-base
-                     text.ss.svn-base
-                     urls.ss.svn-base
-                     xref.ss.svn-base)
+                     search.rkt.svn-base
+                     sigplan.rkt.svn-base
+                     srcdoc.rkt.svn-base
+                     struct.rkt.svn-base
+                     text-render.rkt.svn-base
+                     text.rkt.svn-base
+                     urls.rkt.svn-base
+                     xref.rkt.svn-base)
                     (props)
                     (text-base
-                     base-render.ss.svn-base
-                     base.ss.svn-base
-                     basic.ss.svn-base
-                     bnf.ss.svn-base
-                     comment-reader.ss.svn-base
-                     config.ss.svn-base
-                     core.ss.svn-base
-                     decode-struct.ss.svn-base
-                     decode.ss.svn-base
+                     base-render.rkt.svn-base
+                     base.rkt.svn-base
+                     basic.rkt.svn-base
+                     bnf.rkt.svn-base
+                     comment-reader.rkt.svn-base
+                     config.rkt.svn-base
+                     core.rkt.svn-base
+                     decode-struct.rkt.svn-base
+                     decode.rkt.svn-base
                      doc.txt.svn-base
-                     doclang.ss.svn-base
-                     eval.ss.svn-base
-                     extract.ss.svn-base
-                     html-properties.ss.svn-base
-                     html-render.ss.svn-base
-                     info.ss.svn-base
-                     latex-properties.ss.svn-base
-                     latex-render.ss.svn-base
-                     lp-include.ss.svn-base
-                     lp.ss.svn-base
+                     doclang.rkt.svn-base
+                     eval.rkt.svn-base
+                     extract.rkt.svn-base
+                     html-properties.rkt.svn-base
+                     html-render.rkt.svn-base
+                     info.rkt.svn-base
+                     latex-properties.rkt.svn-base
+                     latex-render.rkt.svn-base
+                     lp-include.rkt.svn-base
+                     lp.rkt.svn-base
                      manual-prefix.tex.svn-base
-                     manual-struct.ss.svn-base
+                     manual-struct.rkt.svn-base
                      manual-style.tex.svn-base
-                     manual.ss.svn-base
-                     pdf-render.ss.svn-base
-                     provide-doc-transform.ss.svn-base
-                     reader.ss.svn-base
-                     render-struct.ss.svn-base
-                     run.ss.svn-base
+                     manual.rkt.svn-base
+                     pdf-render.rkt.svn-base
+                     provide-doc-transform.rkt.svn-base
+                     reader.rkt.svn-base
+                     render-struct.rkt.svn-base
+                     run.rkt.svn-base
                      scheme.css.svn-base
-                     scheme.ss.svn-base
+                     scheme.rkt.svn-base
                      scheme.tex.svn-base
                      scribble-common.js.svn-base
                      scribble-prefix.html.svn-base
@@ -228,14 +228,14 @@
                      scribble-style.tex.svn-base
                      scribble.css.svn-base
                      scribble.tex.svn-base
-                     search.ss.svn-base
-                     sigplan.ss.svn-base
-                     srcdoc.ss.svn-base
-                     struct.ss.svn-base
-                     text-render.ss.svn-base
-                     text.ss.svn-base
-                     urls.ss.svn-base
-                     xref.ss.svn-base)
+                     search.rkt.svn-base
+                     sigplan.rkt.svn-base
+                     srcdoc.rkt.svn-base
+                     struct.rkt.svn-base
+                     text-render.rkt.svn-base
+                     text.rkt.svn-base
+                     urls.rkt.svn-base
+                     xref.rkt.svn-base)
                     (tmp
                      (prop-base)
                      (props)
@@ -247,10 +247,10 @@
                      entries
                      format
                      (prop-base
-                      lang.ss.svn-base)
+                      lang.rkt.svn-base)
                      (props)
                      (text-base
-                      lang.ss.svn-base)
+                      lang.rkt.svn-base)
                      (tmp
                       (prop-base)
                       (props)
@@ -265,10 +265,10 @@
                       entries
                       format
                       (prop-base
-                       reader.ss.svn-base)
+                       reader.rkt.svn-base)
                       (props)
                       (text-base
-                       reader.ss.svn-base)
+                       reader.rkt.svn-base)
                       (tmp
                        (prop-base)
                        (props)
@@ -276,13 +276,13 @@
                      (compiled
                       reader_ss.dep
                       reader_ss.zo)
-                     reader.ss)
-                    lang.ss)
-                   base-render.ss
-                   base.ss
-                   basic.ss
-                   bnf.ss
-                   comment-reader.ss
+                     reader.rkt)
+                    lang.rkt)
+                   base-render.rkt
+                   base.rkt
+                   basic.rkt
+                   bnf.rkt
+                   comment-reader.rkt
                    (compiled
                     base-render_ss.dep
                     base-render_ss.zo
@@ -354,10 +354,10 @@
                     urls_ss.zo
                     xref_ss.dep
                     xref_ss.zo)
-                   config.ss
-                   core.ss
-                   decode-struct.ss
-                   decode.ss
+                   config.rkt
+                   core.rkt
+                   decode-struct.rkt
+                   decode.rkt
                    (doc
                     (.svn
                      all-wcprops
@@ -365,12 +365,12 @@
                      entries
                      format
                      (prop-base
-                      main.ss.svn-base
-                      reader.ss.svn-base)
+                      main.rkt.svn-base
+                      reader.rkt.svn-base)
                      (props)
                      (text-base
-                      main.ss.svn-base
-                      reader.ss.svn-base)
+                      main.rkt.svn-base
+                      reader.rkt.svn-base)
                      (tmp
                       (prop-base)
                       (props)
@@ -387,10 +387,10 @@
                       entries
                       format
                       (prop-base
-                       reader.ss.svn-base)
+                       reader.rkt.svn-base)
                       (props)
                       (text-base
-                       reader.ss.svn-base)
+                       reader.rkt.svn-base)
                       (tmp
                        (prop-base)
                        (props)
@@ -398,18 +398,18 @@
                      (compiled
                       reader_ss.dep
                       reader_ss.zo)
-                     reader.ss)
-                    main.ss
-                    reader.ss)
+                     reader.rkt)
+                    main.rkt
+                    reader.rkt)
                    doc.txt
-                   doclang.ss
-                   eval.ss
-                   extract.ss
-                   html-properties.ss
-                   html-render.ss
-                   info.ss
-                   latex-properties.ss
-                   latex-render.ss
+                   doclang.rkt
+                   eval.rkt
+                   extract.rkt
+                   html-properties.rkt
+                   html-render.rkt
+                   info.rkt
+                   latex-properties.rkt
+                   latex-render.rkt
                    (lp
                     (.svn
                      all-wcprops
@@ -429,12 +429,12 @@
                       entries
                       format
                       (prop-base
-                       lang.ss.svn-base
-                       reader.ss.svn-base)
+                       lang.rkt.svn-base
+                       reader.rkt.svn-base)
                       (props)
                       (text-base
-                       lang.ss.svn-base
-                       reader.ss.svn-base)
+                       lang.rkt.svn-base
+                       reader.rkt.svn-base)
                       (tmp
                        (prop-base)
                        (props)
@@ -444,10 +444,10 @@
                       lang_ss.zo
                       reader_ss.dep
                       reader_ss.zo)
-                     lang.ss
-                     reader.ss))
-                   lp-include.ss
-                   lp.ss
+                     lang.rkt
+                     reader.rkt))
+                   lp-include.rkt
+                   lp.rkt
                    (manual
                     (.svn
                      all-wcprops
@@ -455,10 +455,10 @@
                      entries
                      format
                      (prop-base
-                      lang.ss.svn-base)
+                      lang.rkt.svn-base)
                      (props)
                      (text-base
-                      lang.ss.svn-base)
+                      lang.rkt.svn-base)
                      (tmp
                       (prop-base)
                       (props)
@@ -473,10 +473,10 @@
                       entries
                       format
                       (prop-base
-                       reader.ss.svn-base)
+                       reader.rkt.svn-base)
                       (props)
                       (text-base
-                       reader.ss.svn-base)
+                       reader.rkt.svn-base)
                       (tmp
                        (prop-base)
                        (props)
@@ -484,13 +484,13 @@
                      (compiled
                       reader_ss.dep
                       reader_ss.zo)
-                     reader.ss)
-                    lang.ss)
+                     reader.rkt)
+                    lang.rkt)
                    manual-prefix.tex
-                   manual-struct.ss
+                   manual-struct.rkt
                    manual-style.tex
-                   manual.ss
-                   pdf-render.ss
+                   manual.rkt
+                   pdf-render.rkt
                    (private
                     (.svn
                      all-wcprops
@@ -498,54 +498,54 @@
                      entries
                      format
                      (prop-base
-                      defaults.ss.svn-base
-                      indirect-renderer.ss.svn-base
-                      lp.ss.svn-base
-                      manual-bib.ss.svn-base
-                      manual-bind.ss.svn-base
-                      manual-class.ss.svn-base
-                      manual-ex.ss.svn-base
-                      manual-form.ss.svn-base
-                      manual-method.ss.svn-base
-                      manual-mod.ss.svn-base
-                      manual-proc.ss.svn-base
-                      manual-scheme.ss.svn-base
-                      manual-sprop.ss.svn-base
-                      manual-style.ss.svn-base
-                      manual-tech.ss.svn-base
-                      manual-unit.ss.svn-base
-                      manual-utils.ss.svn-base
-                      manual-vars.ss.svn-base
-                      on-demand.ss.svn-base
-                      provide-structs.ss.svn-base
-                      qsloc.ss.svn-base
-                      render-utils.ss.svn-base
-                      run-pdflatex.ss.svn-base)
+                      defaults.rkt.svn-base
+                      indirect-renderer.rkt.svn-base
+                      lp.rkt.svn-base
+                      manual-bib.rkt.svn-base
+                      manual-bind.rkt.svn-base
+                      manual-class.rkt.svn-base
+                      manual-ex.rkt.svn-base
+                      manual-form.rkt.svn-base
+                      manual-method.rkt.svn-base
+                      manual-mod.rkt.svn-base
+                      manual-proc.rkt.svn-base
+                      manual-scheme.rkt.svn-base
+                      manual-sprop.rkt.svn-base
+                      manual-style.rkt.svn-base
+                      manual-tech.rkt.svn-base
+                      manual-unit.rkt.svn-base
+                      manual-utils.rkt.svn-base
+                      manual-vars.rkt.svn-base
+                      on-demand.rkt.svn-base
+                      provide-structs.rkt.svn-base
+                      qsloc.rkt.svn-base
+                      render-utils.rkt.svn-base
+                      run-pdflatex.rkt.svn-base)
                      (props)
                      (text-base
-                      defaults.ss.svn-base
-                      indirect-renderer.ss.svn-base
-                      lp.ss.svn-base
-                      manual-bib.ss.svn-base
-                      manual-bind.ss.svn-base
-                      manual-class.ss.svn-base
-                      manual-ex.ss.svn-base
-                      manual-form.ss.svn-base
-                      manual-method.ss.svn-base
-                      manual-mod.ss.svn-base
-                      manual-proc.ss.svn-base
-                      manual-scheme.ss.svn-base
-                      manual-sprop.ss.svn-base
-                      manual-style.ss.svn-base
-                      manual-tech.ss.svn-base
-                      manual-unit.ss.svn-base
-                      manual-utils.ss.svn-base
-                      manual-vars.ss.svn-base
-                      on-demand.ss.svn-base
-                      provide-structs.ss.svn-base
-                      qsloc.ss.svn-base
-                      render-utils.ss.svn-base
-                      run-pdflatex.ss.svn-base)
+                      defaults.rkt.svn-base
+                      indirect-renderer.rkt.svn-base
+                      lp.rkt.svn-base
+                      manual-bib.rkt.svn-base
+                      manual-bind.rkt.svn-base
+                      manual-class.rkt.svn-base
+                      manual-ex.rkt.svn-base
+                      manual-form.rkt.svn-base
+                      manual-method.rkt.svn-base
+                      manual-mod.rkt.svn-base
+                      manual-proc.rkt.svn-base
+                      manual-scheme.rkt.svn-base
+                      manual-sprop.rkt.svn-base
+                      manual-style.rkt.svn-base
+                      manual-tech.rkt.svn-base
+                      manual-unit.rkt.svn-base
+                      manual-utils.rkt.svn-base
+                      manual-vars.rkt.svn-base
+                      on-demand.rkt.svn-base
+                      provide-structs.rkt.svn-base
+                      qsloc.rkt.svn-base
+                      render-utils.rkt.svn-base
+                      run-pdflatex.rkt.svn-base)
                      (tmp
                       (prop-base)
                       (props)
@@ -597,35 +597,35 @@
                      render-utils_ss.zo
                      run-pdflatex_ss.dep
                      run-pdflatex_ss.zo)
-                    defaults.ss
-                    indirect-renderer.ss
-                    lp.ss
-                    manual-bib.ss
-                    manual-bind.ss
-                    manual-class.ss
-                    manual-ex.ss
-                    manual-form.ss
-                    manual-method.ss
-                    manual-mod.ss
-                    manual-proc.ss
-                    manual-scheme.ss
-                    manual-sprop.ss
-                    manual-style.ss
-                    manual-tech.ss
-                    manual-unit.ss
-                    manual-utils.ss
-                    manual-vars.ss
-                    on-demand.ss
-                    provide-structs.ss
-                    qsloc.ss
-                    render-utils.ss
-                    run-pdflatex.ss)
-                   provide-doc-transform.ss
-                   reader.ss
-                   render-struct.ss
-                   run.ss
+                    defaults.rkt
+                    indirect-renderer.rkt
+                    lp.rkt
+                    manual-bib.rkt
+                    manual-bind.rkt
+                    manual-class.rkt
+                    manual-ex.rkt
+                    manual-form.rkt
+                    manual-method.rkt
+                    manual-mod.rkt
+                    manual-proc.rkt
+                    manual-scheme.rkt
+                    manual-sprop.rkt
+                    manual-style.rkt
+                    manual-tech.rkt
+                    manual-unit.rkt
+                    manual-utils.rkt
+                    manual-vars.rkt
+                    on-demand.rkt
+                    provide-structs.rkt
+                    qsloc.rkt
+                    render-utils.rkt
+                    run-pdflatex.rkt)
+                   provide-doc-transform.rkt
+                   reader.rkt
+                   render-struct.rkt
+                   run.rkt
                    scheme.css
-                   scheme.ss
+                   scheme.rkt
                    scheme.tex
                    scribble-common.js
                    scribble-prefix.html
@@ -634,7 +634,7 @@
                    scribble-style.tex
                    scribble.css
                    scribble.tex
-                   search.ss
+                   search.rkt
                    (sigplan
                     (.svn
                      all-wcprops
@@ -642,14 +642,14 @@
                      entries
                      format
                      (prop-base
-                      lang.ss.svn-base
+                      lang.rkt.svn-base
                       sigplan.css.svn-base
                       sigplan.tex.svn-base
                       sigplanconf.cls.svn-base
                       style.tex.svn-base)
                      (props)
                      (text-base
-                      lang.ss.svn-base
+                      lang.rkt.svn-base
                       sigplan.css.svn-base
                       sigplan.tex.svn-base
                       sigplanconf.cls.svn-base
@@ -668,10 +668,10 @@
                       entries
                       format
                       (prop-base
-                       reader.ss.svn-base)
+                       reader.rkt.svn-base)
                       (props)
                       (text-base
-                       reader.ss.svn-base)
+                       reader.rkt.svn-base)
                       (tmp
                        (prop-base)
                        (props)
@@ -679,15 +679,15 @@
                      (compiled
                       reader_ss.dep
                       reader_ss.zo)
-                     reader.ss)
-                    lang.ss
+                     reader.rkt)
+                    lang.rkt
                     sigplan.css
                     sigplan.tex
                     sigplanconf.cls
                     style.tex)
-                   sigplan.ss
-                   srcdoc.ss
-                   struct.ss
+                   sigplan.rkt
+                   srcdoc.rkt
+                   struct.rkt
                    (text
                     (.svn
                      all-wcprops
@@ -695,14 +695,14 @@
                      entries
                      format
                      (prop-base
-                      output.ss.svn-base
-                      syntax-utils.ss.svn-base
-                      textlang.ss.svn-base)
+                      output.rkt.svn-base
+                      syntax-utils.rkt.svn-base
+                      textlang.rkt.svn-base)
                      (props)
                      (text-base
-                      output.ss.svn-base
-                      syntax-utils.ss.svn-base
-                      textlang.ss.svn-base)
+                      output.rkt.svn-base
+                      syntax-utils.rkt.svn-base
+                      textlang.rkt.svn-base)
                      (tmp
                       (prop-base)
                       (props)
@@ -721,10 +721,10 @@
                       entries
                       format
                       (prop-base
-                       reader.ss.svn-base)
+                       reader.rkt.svn-base)
                       (props)
                       (text-base
-                       reader.ss.svn-base)
+                       reader.rkt.svn-base)
                       (tmp
                        (prop-base)
                        (props)
@@ -732,12 +732,12 @@
                      (compiled
                       reader_ss.dep
                       reader_ss.zo)
-                     reader.ss)
-                    output.ss
-                    syntax-utils.ss
-                    textlang.ss)
-                   text-render.ss
-                   text.ss
+                     reader.rkt)
+                    output.rkt
+                    syntax-utils.rkt
+                    textlang.rkt)
+                   text-render.rkt
+                   text.rkt
                    (tools
                     (.svn
                      all-wcprops
@@ -745,12 +745,12 @@
                      entries
                      format
                      (prop-base
-                      drscheme-buttons.ss.svn-base
+                      drscheme-buttons.rkt.svn-base
                       html.png.svn-base
                       pdf.png.svn-base)
                      (props)
                      (text-base
-                      drscheme-buttons.ss.svn-base
+                      drscheme-buttons.rkt.svn-base
                       html.png.svn-base
                       pdf.png.svn-base)
                      (tmp
@@ -760,7 +760,7 @@
                     (compiled
                      drscheme-buttons_ss.dep
                      drscheme-buttons_ss.zo)
-                    drscheme-buttons.ss
+                    drscheme-buttons.rkt
                     html.png
                     pdf.png
                     (private
@@ -770,10 +770,10 @@
                       entries
                       format
                       (prop-base
-                       mk-drs-bitmaps.ss.svn-base)
+                       mk-drs-bitmaps.rkt.svn-base)
                       (props)
                       (text-base
-                       mk-drs-bitmaps.ss.svn-base)
+                       mk-drs-bitmaps.rkt.svn-base)
                       (tmp
                        (prop-base)
                        (props)
@@ -781,9 +781,9 @@
                      (compiled
                       mk-drs-bitmaps_ss.dep
                       mk-drs-bitmaps_ss.zo)
-                     mk-drs-bitmaps.ss))
-                   urls.ss
-                   xref.ss)))
+                     mk-drs-bitmaps.rkt))
+                   urls.rkt
+                   xref.rkt)))
   (test
    ;; the whole tree
    (e/filter "*")
@@ -796,37 +796,37 @@
      -/.svn/entries
      -/.svn/format
      -/.svn/prop-base/
-     -/.svn/prop-base/base-render.ss.svn-base
-     -/.svn/prop-base/base.ss.svn-base
-     -/.svn/prop-base/basic.ss.svn-base
-     -/.svn/prop-base/bnf.ss.svn-base
-     -/.svn/prop-base/comment-reader.ss.svn-base
-     -/.svn/prop-base/config.ss.svn-base
-     -/.svn/prop-base/core.ss.svn-base
-     -/.svn/prop-base/decode-struct.ss.svn-base
-     -/.svn/prop-base/decode.ss.svn-base
+     -/.svn/prop-base/base-render.rkt.svn-base
+     -/.svn/prop-base/base.rkt.svn-base
+     -/.svn/prop-base/basic.rkt.svn-base
+     -/.svn/prop-base/bnf.rkt.svn-base
+     -/.svn/prop-base/comment-reader.rkt.svn-base
+     -/.svn/prop-base/config.rkt.svn-base
+     -/.svn/prop-base/core.rkt.svn-base
+     -/.svn/prop-base/decode-struct.rkt.svn-base
+     -/.svn/prop-base/decode.rkt.svn-base
      -/.svn/prop-base/doc.txt.svn-base
-     -/.svn/prop-base/doclang.ss.svn-base
-     -/.svn/prop-base/eval.ss.svn-base
-     -/.svn/prop-base/extract.ss.svn-base
-     -/.svn/prop-base/html-properties.ss.svn-base
-     -/.svn/prop-base/html-render.ss.svn-base
-     -/.svn/prop-base/info.ss.svn-base
-     -/.svn/prop-base/latex-properties.ss.svn-base
-     -/.svn/prop-base/latex-render.ss.svn-base
-     -/.svn/prop-base/lp-include.ss.svn-base
-     -/.svn/prop-base/lp.ss.svn-base
+     -/.svn/prop-base/doclang.rkt.svn-base
+     -/.svn/prop-base/eval.rkt.svn-base
+     -/.svn/prop-base/extract.rkt.svn-base
+     -/.svn/prop-base/html-properties.rkt.svn-base
+     -/.svn/prop-base/html-render.rkt.svn-base
+     -/.svn/prop-base/info.rkt.svn-base
+     -/.svn/prop-base/latex-properties.rkt.svn-base
+     -/.svn/prop-base/latex-render.rkt.svn-base
+     -/.svn/prop-base/lp-include.rkt.svn-base
+     -/.svn/prop-base/lp.rkt.svn-base
      -/.svn/prop-base/manual-prefix.tex.svn-base
-     -/.svn/prop-base/manual-struct.ss.svn-base
+     -/.svn/prop-base/manual-struct.rkt.svn-base
      -/.svn/prop-base/manual-style.tex.svn-base
-     -/.svn/prop-base/manual.ss.svn-base
-     -/.svn/prop-base/pdf-render.ss.svn-base
-     -/.svn/prop-base/provide-doc-transform.ss.svn-base
-     -/.svn/prop-base/reader.ss.svn-base
-     -/.svn/prop-base/render-struct.ss.svn-base
-     -/.svn/prop-base/run.ss.svn-base
+     -/.svn/prop-base/manual.rkt.svn-base
+     -/.svn/prop-base/pdf-render.rkt.svn-base
+     -/.svn/prop-base/provide-doc-transform.rkt.svn-base
+     -/.svn/prop-base/reader.rkt.svn-base
+     -/.svn/prop-base/render-struct.rkt.svn-base
+     -/.svn/prop-base/run.rkt.svn-base
      -/.svn/prop-base/scheme.css.svn-base
-     -/.svn/prop-base/scheme.ss.svn-base
+     -/.svn/prop-base/scheme.rkt.svn-base
      -/.svn/prop-base/scheme.tex.svn-base
      -/.svn/prop-base/scribble-common.js.svn-base
      -/.svn/prop-base/scribble-prefix.html.svn-base
@@ -835,47 +835,47 @@
      -/.svn/prop-base/scribble-style.tex.svn-base
      -/.svn/prop-base/scribble.css.svn-base
      -/.svn/prop-base/scribble.tex.svn-base
-     -/.svn/prop-base/search.ss.svn-base
-     -/.svn/prop-base/sigplan.ss.svn-base
-     -/.svn/prop-base/srcdoc.ss.svn-base
-     -/.svn/prop-base/struct.ss.svn-base
-     -/.svn/prop-base/text-render.ss.svn-base
-     -/.svn/prop-base/text.ss.svn-base
-     -/.svn/prop-base/urls.ss.svn-base
-     -/.svn/prop-base/xref.ss.svn-base
+     -/.svn/prop-base/search.rkt.svn-base
+     -/.svn/prop-base/sigplan.rkt.svn-base
+     -/.svn/prop-base/srcdoc.rkt.svn-base
+     -/.svn/prop-base/struct.rkt.svn-base
+     -/.svn/prop-base/text-render.rkt.svn-base
+     -/.svn/prop-base/text.rkt.svn-base
+     -/.svn/prop-base/urls.rkt.svn-base
+     -/.svn/prop-base/xref.rkt.svn-base
      -/.svn/props/
      -/.svn/text-base/
-     -/.svn/text-base/base-render.ss.svn-base
-     -/.svn/text-base/base.ss.svn-base
-     -/.svn/text-base/basic.ss.svn-base
-     -/.svn/text-base/bnf.ss.svn-base
-     -/.svn/text-base/comment-reader.ss.svn-base
-     -/.svn/text-base/config.ss.svn-base
-     -/.svn/text-base/core.ss.svn-base
-     -/.svn/text-base/decode-struct.ss.svn-base
-     -/.svn/text-base/decode.ss.svn-base
+     -/.svn/text-base/base-render.rkt.svn-base
+     -/.svn/text-base/base.rkt.svn-base
+     -/.svn/text-base/basic.rkt.svn-base
+     -/.svn/text-base/bnf.rkt.svn-base
+     -/.svn/text-base/comment-reader.rkt.svn-base
+     -/.svn/text-base/config.rkt.svn-base
+     -/.svn/text-base/core.rkt.svn-base
+     -/.svn/text-base/decode-struct.rkt.svn-base
+     -/.svn/text-base/decode.rkt.svn-base
      -/.svn/text-base/doc.txt.svn-base
-     -/.svn/text-base/doclang.ss.svn-base
-     -/.svn/text-base/eval.ss.svn-base
-     -/.svn/text-base/extract.ss.svn-base
-     -/.svn/text-base/html-properties.ss.svn-base
-     -/.svn/text-base/html-render.ss.svn-base
-     -/.svn/text-base/info.ss.svn-base
-     -/.svn/text-base/latex-properties.ss.svn-base
-     -/.svn/text-base/latex-render.ss.svn-base
-     -/.svn/text-base/lp-include.ss.svn-base
-     -/.svn/text-base/lp.ss.svn-base
+     -/.svn/text-base/doclang.rkt.svn-base
+     -/.svn/text-base/eval.rkt.svn-base
+     -/.svn/text-base/extract.rkt.svn-base
+     -/.svn/text-base/html-properties.rkt.svn-base
+     -/.svn/text-base/html-render.rkt.svn-base
+     -/.svn/text-base/info.rkt.svn-base
+     -/.svn/text-base/latex-properties.rkt.svn-base
+     -/.svn/text-base/latex-render.rkt.svn-base
+     -/.svn/text-base/lp-include.rkt.svn-base
+     -/.svn/text-base/lp.rkt.svn-base
      -/.svn/text-base/manual-prefix.tex.svn-base
-     -/.svn/text-base/manual-struct.ss.svn-base
+     -/.svn/text-base/manual-struct.rkt.svn-base
      -/.svn/text-base/manual-style.tex.svn-base
-     -/.svn/text-base/manual.ss.svn-base
-     -/.svn/text-base/pdf-render.ss.svn-base
-     -/.svn/text-base/provide-doc-transform.ss.svn-base
-     -/.svn/text-base/reader.ss.svn-base
-     -/.svn/text-base/render-struct.ss.svn-base
-     -/.svn/text-base/run.ss.svn-base
+     -/.svn/text-base/manual.rkt.svn-base
+     -/.svn/text-base/pdf-render.rkt.svn-base
+     -/.svn/text-base/provide-doc-transform.rkt.svn-base
+     -/.svn/text-base/reader.rkt.svn-base
+     -/.svn/text-base/render-struct.rkt.svn-base
+     -/.svn/text-base/run.rkt.svn-base
      -/.svn/text-base/scheme.css.svn-base
-     -/.svn/text-base/scheme.ss.svn-base
+     -/.svn/text-base/scheme.rkt.svn-base
      -/.svn/text-base/scheme.tex.svn-base
      -/.svn/text-base/scribble-common.js.svn-base
      -/.svn/text-base/scribble-prefix.html.svn-base
@@ -884,14 +884,14 @@
      -/.svn/text-base/scribble-style.tex.svn-base
      -/.svn/text-base/scribble.css.svn-base
      -/.svn/text-base/scribble.tex.svn-base
-     -/.svn/text-base/search.ss.svn-base
-     -/.svn/text-base/sigplan.ss.svn-base
-     -/.svn/text-base/srcdoc.ss.svn-base
-     -/.svn/text-base/struct.ss.svn-base
-     -/.svn/text-base/text-render.ss.svn-base
-     -/.svn/text-base/text.ss.svn-base
-     -/.svn/text-base/urls.ss.svn-base
-     -/.svn/text-base/xref.ss.svn-base
+     -/.svn/text-base/search.rkt.svn-base
+     -/.svn/text-base/sigplan.rkt.svn-base
+     -/.svn/text-base/srcdoc.rkt.svn-base
+     -/.svn/text-base/struct.rkt.svn-base
+     -/.svn/text-base/text-render.rkt.svn-base
+     -/.svn/text-base/text.rkt.svn-base
+     -/.svn/text-base/urls.rkt.svn-base
+     -/.svn/text-base/xref.rkt.svn-base
      -/.svn/tmp/
      -/.svn/tmp/prop-base/
      -/.svn/tmp/props/
@@ -903,10 +903,10 @@
      -/base/.svn/entries
      -/base/.svn/format
      -/base/.svn/prop-base/
-     -/base/.svn/prop-base/lang.ss.svn-base
+     -/base/.svn/prop-base/lang.rkt.svn-base
      -/base/.svn/props/
      -/base/.svn/text-base/
-     -/base/.svn/text-base/lang.ss.svn-base
+     -/base/.svn/text-base/lang.rkt.svn-base
      -/base/.svn/tmp/
      -/base/.svn/tmp/prop-base/
      -/base/.svn/tmp/props/
@@ -921,10 +921,10 @@
      -/base/lang/.svn/entries
      -/base/lang/.svn/format
      -/base/lang/.svn/prop-base/
-     -/base/lang/.svn/prop-base/reader.ss.svn-base
+     -/base/lang/.svn/prop-base/reader.rkt.svn-base
      -/base/lang/.svn/props/
      -/base/lang/.svn/text-base/
-     -/base/lang/.svn/text-base/reader.ss.svn-base
+     -/base/lang/.svn/text-base/reader.rkt.svn-base
      -/base/lang/.svn/tmp/
      -/base/lang/.svn/tmp/prop-base/
      -/base/lang/.svn/tmp/props/
@@ -932,13 +932,13 @@
      -/base/lang/compiled/
      -/base/lang/compiled/reader_ss.dep
      -/base/lang/compiled/reader_ss.zo
-     -/base/lang/reader.ss
-     -/base/lang.ss
-     -/base-render.ss
-     -/base.ss
-     -/basic.ss
-     -/bnf.ss
-     -/comment-reader.ss
+     -/base/lang/reader.rkt
+     -/base/lang.rkt
+     -/base-render.rkt
+     -/base.rkt
+     -/basic.rkt
+     -/bnf.rkt
+     -/comment-reader.rkt
      -/compiled/
      -/compiled/base-render_ss.dep
      -/compiled/base-render_ss.zo
@@ -1010,10 +1010,10 @@
      -/compiled/urls_ss.zo
      -/compiled/xref_ss.dep
      -/compiled/xref_ss.zo
-     -/config.ss
-     -/core.ss
-     -/decode-struct.ss
-     -/decode.ss
+     -/config.rkt
+     -/core.rkt
+     -/decode-struct.rkt
+     -/decode.rkt
      -/doc/
      -/doc/.svn/
      -/doc/.svn/all-wcprops
@@ -1021,12 +1021,12 @@
      -/doc/.svn/entries
      -/doc/.svn/format
      -/doc/.svn/prop-base/
-     -/doc/.svn/prop-base/main.ss.svn-base
-     -/doc/.svn/prop-base/reader.ss.svn-base
+     -/doc/.svn/prop-base/main.rkt.svn-base
+     -/doc/.svn/prop-base/reader.rkt.svn-base
      -/doc/.svn/props/
      -/doc/.svn/text-base/
-     -/doc/.svn/text-base/main.ss.svn-base
-     -/doc/.svn/text-base/reader.ss.svn-base
+     -/doc/.svn/text-base/main.rkt.svn-base
+     -/doc/.svn/text-base/reader.rkt.svn-base
      -/doc/.svn/tmp/
      -/doc/.svn/tmp/prop-base/
      -/doc/.svn/tmp/props/
@@ -1043,10 +1043,10 @@
      -/doc/lang/.svn/entries
      -/doc/lang/.svn/format
      -/doc/lang/.svn/prop-base/
-     -/doc/lang/.svn/prop-base/reader.ss.svn-base
+     -/doc/lang/.svn/prop-base/reader.rkt.svn-base
      -/doc/lang/.svn/props/
      -/doc/lang/.svn/text-base/
-     -/doc/lang/.svn/text-base/reader.ss.svn-base
+     -/doc/lang/.svn/text-base/reader.rkt.svn-base
      -/doc/lang/.svn/tmp/
      -/doc/lang/.svn/tmp/prop-base/
      -/doc/lang/.svn/tmp/props/
@@ -1054,18 +1054,18 @@
      -/doc/lang/compiled/
      -/doc/lang/compiled/reader_ss.dep
      -/doc/lang/compiled/reader_ss.zo
-     -/doc/lang/reader.ss
-     -/doc/main.ss
-     -/doc/reader.ss
+     -/doc/lang/reader.rkt
+     -/doc/main.rkt
+     -/doc/reader.rkt
      -/doc.txt
-     -/doclang.ss
-     -/eval.ss
-     -/extract.ss
-     -/html-properties.ss
-     -/html-render.ss
-     -/info.ss
-     -/latex-properties.ss
-     -/latex-render.ss
+     -/doclang.rkt
+     -/eval.rkt
+     -/extract.rkt
+     -/html-properties.rkt
+     -/html-render.rkt
+     -/info.rkt
+     -/latex-properties.rkt
+     -/latex-render.rkt
      -/lp/
      -/lp/.svn/
      -/lp/.svn/all-wcprops
@@ -1085,12 +1085,12 @@
      -/lp/lang/.svn/entries
      -/lp/lang/.svn/format
      -/lp/lang/.svn/prop-base/
-     -/lp/lang/.svn/prop-base/lang.ss.svn-base
-     -/lp/lang/.svn/prop-base/reader.ss.svn-base
+     -/lp/lang/.svn/prop-base/lang.rkt.svn-base
+     -/lp/lang/.svn/prop-base/reader.rkt.svn-base
      -/lp/lang/.svn/props/
      -/lp/lang/.svn/text-base/
-     -/lp/lang/.svn/text-base/lang.ss.svn-base
-     -/lp/lang/.svn/text-base/reader.ss.svn-base
+     -/lp/lang/.svn/text-base/lang.rkt.svn-base
+     -/lp/lang/.svn/text-base/reader.rkt.svn-base
      -/lp/lang/.svn/tmp/
      -/lp/lang/.svn/tmp/prop-base/
      -/lp/lang/.svn/tmp/props/
@@ -1100,10 +1100,10 @@
      -/lp/lang/compiled/lang_ss.zo
      -/lp/lang/compiled/reader_ss.dep
      -/lp/lang/compiled/reader_ss.zo
-     -/lp/lang/lang.ss
-     -/lp/lang/reader.ss
-     -/lp-include.ss
-     -/lp.ss
+     -/lp/lang/lang.rkt
+     -/lp/lang/reader.rkt
+     -/lp-include.rkt
+     -/lp.rkt
      -/manual/
      -/manual/.svn/
      -/manual/.svn/all-wcprops
@@ -1111,10 +1111,10 @@
      -/manual/.svn/entries
      -/manual/.svn/format
      -/manual/.svn/prop-base/
-     -/manual/.svn/prop-base/lang.ss.svn-base
+     -/manual/.svn/prop-base/lang.rkt.svn-base
      -/manual/.svn/props/
      -/manual/.svn/text-base/
-     -/manual/.svn/text-base/lang.ss.svn-base
+     -/manual/.svn/text-base/lang.rkt.svn-base
      -/manual/.svn/tmp/
      -/manual/.svn/tmp/prop-base/
      -/manual/.svn/tmp/props/
@@ -1129,10 +1129,10 @@
      -/manual/lang/.svn/entries
      -/manual/lang/.svn/format
      -/manual/lang/.svn/prop-base/
-     -/manual/lang/.svn/prop-base/reader.ss.svn-base
+     -/manual/lang/.svn/prop-base/reader.rkt.svn-base
      -/manual/lang/.svn/props/
      -/manual/lang/.svn/text-base/
-     -/manual/lang/.svn/text-base/reader.ss.svn-base
+     -/manual/lang/.svn/text-base/reader.rkt.svn-base
      -/manual/lang/.svn/tmp/
      -/manual/lang/.svn/tmp/prop-base/
      -/manual/lang/.svn/tmp/props/
@@ -1140,13 +1140,13 @@
      -/manual/lang/compiled/
      -/manual/lang/compiled/reader_ss.dep
      -/manual/lang/compiled/reader_ss.zo
-     -/manual/lang/reader.ss
-     -/manual/lang.ss
+     -/manual/lang/reader.rkt
+     -/manual/lang.rkt
      -/manual-prefix.tex
-     -/manual-struct.ss
+     -/manual-struct.rkt
      -/manual-style.tex
-     -/manual.ss
-     -/pdf-render.ss
+     -/manual.rkt
+     -/pdf-render.rkt
      -/private/
      -/private/.svn/
      -/private/.svn/all-wcprops
@@ -1154,54 +1154,54 @@
      -/private/.svn/entries
      -/private/.svn/format
      -/private/.svn/prop-base/
-     -/private/.svn/prop-base/defaults.ss.svn-base
-     -/private/.svn/prop-base/indirect-renderer.ss.svn-base
-     -/private/.svn/prop-base/lp.ss.svn-base
-     -/private/.svn/prop-base/manual-bib.ss.svn-base
-     -/private/.svn/prop-base/manual-bind.ss.svn-base
-     -/private/.svn/prop-base/manual-class.ss.svn-base
-     -/private/.svn/prop-base/manual-ex.ss.svn-base
-     -/private/.svn/prop-base/manual-form.ss.svn-base
-     -/private/.svn/prop-base/manual-method.ss.svn-base
-     -/private/.svn/prop-base/manual-mod.ss.svn-base
-     -/private/.svn/prop-base/manual-proc.ss.svn-base
-     -/private/.svn/prop-base/manual-scheme.ss.svn-base
-     -/private/.svn/prop-base/manual-sprop.ss.svn-base
-     -/private/.svn/prop-base/manual-style.ss.svn-base
-     -/private/.svn/prop-base/manual-tech.ss.svn-base
-     -/private/.svn/prop-base/manual-unit.ss.svn-base
-     -/private/.svn/prop-base/manual-utils.ss.svn-base
-     -/private/.svn/prop-base/manual-vars.ss.svn-base
-     -/private/.svn/prop-base/on-demand.ss.svn-base
-     -/private/.svn/prop-base/provide-structs.ss.svn-base
-     -/private/.svn/prop-base/qsloc.ss.svn-base
-     -/private/.svn/prop-base/render-utils.ss.svn-base
-     -/private/.svn/prop-base/run-pdflatex.ss.svn-base
+     -/private/.svn/prop-base/defaults.rkt.svn-base
+     -/private/.svn/prop-base/indirect-renderer.rkt.svn-base
+     -/private/.svn/prop-base/lp.rkt.svn-base
+     -/private/.svn/prop-base/manual-bib.rkt.svn-base
+     -/private/.svn/prop-base/manual-bind.rkt.svn-base
+     -/private/.svn/prop-base/manual-class.rkt.svn-base
+     -/private/.svn/prop-base/manual-ex.rkt.svn-base
+     -/private/.svn/prop-base/manual-form.rkt.svn-base
+     -/private/.svn/prop-base/manual-method.rkt.svn-base
+     -/private/.svn/prop-base/manual-mod.rkt.svn-base
+     -/private/.svn/prop-base/manual-proc.rkt.svn-base
+     -/private/.svn/prop-base/manual-scheme.rkt.svn-base
+     -/private/.svn/prop-base/manual-sprop.rkt.svn-base
+     -/private/.svn/prop-base/manual-style.rkt.svn-base
+     -/private/.svn/prop-base/manual-tech.rkt.svn-base
+     -/private/.svn/prop-base/manual-unit.rkt.svn-base
+     -/private/.svn/prop-base/manual-utils.rkt.svn-base
+     -/private/.svn/prop-base/manual-vars.rkt.svn-base
+     -/private/.svn/prop-base/on-demand.rkt.svn-base
+     -/private/.svn/prop-base/provide-structs.rkt.svn-base
+     -/private/.svn/prop-base/qsloc.rkt.svn-base
+     -/private/.svn/prop-base/render-utils.rkt.svn-base
+     -/private/.svn/prop-base/run-pdflatex.rkt.svn-base
      -/private/.svn/props/
      -/private/.svn/text-base/
-     -/private/.svn/text-base/defaults.ss.svn-base
-     -/private/.svn/text-base/indirect-renderer.ss.svn-base
-     -/private/.svn/text-base/lp.ss.svn-base
-     -/private/.svn/text-base/manual-bib.ss.svn-base
-     -/private/.svn/text-base/manual-bind.ss.svn-base
-     -/private/.svn/text-base/manual-class.ss.svn-base
-     -/private/.svn/text-base/manual-ex.ss.svn-base
-     -/private/.svn/text-base/manual-form.ss.svn-base
-     -/private/.svn/text-base/manual-method.ss.svn-base
-     -/private/.svn/text-base/manual-mod.ss.svn-base
-     -/private/.svn/text-base/manual-proc.ss.svn-base
-     -/private/.svn/text-base/manual-scheme.ss.svn-base
-     -/private/.svn/text-base/manual-sprop.ss.svn-base
-     -/private/.svn/text-base/manual-style.ss.svn-base
-     -/private/.svn/text-base/manual-tech.ss.svn-base
-     -/private/.svn/text-base/manual-unit.ss.svn-base
-     -/private/.svn/text-base/manual-utils.ss.svn-base
-     -/private/.svn/text-base/manual-vars.ss.svn-base
-     -/private/.svn/text-base/on-demand.ss.svn-base
-     -/private/.svn/text-base/provide-structs.ss.svn-base
-     -/private/.svn/text-base/qsloc.ss.svn-base
-     -/private/.svn/text-base/render-utils.ss.svn-base
-     -/private/.svn/text-base/run-pdflatex.ss.svn-base
+     -/private/.svn/text-base/defaults.rkt.svn-base
+     -/private/.svn/text-base/indirect-renderer.rkt.svn-base
+     -/private/.svn/text-base/lp.rkt.svn-base
+     -/private/.svn/text-base/manual-bib.rkt.svn-base
+     -/private/.svn/text-base/manual-bind.rkt.svn-base
+     -/private/.svn/text-base/manual-class.rkt.svn-base
+     -/private/.svn/text-base/manual-ex.rkt.svn-base
+     -/private/.svn/text-base/manual-form.rkt.svn-base
+     -/private/.svn/text-base/manual-method.rkt.svn-base
+     -/private/.svn/text-base/manual-mod.rkt.svn-base
+     -/private/.svn/text-base/manual-proc.rkt.svn-base
+     -/private/.svn/text-base/manual-scheme.rkt.svn-base
+     -/private/.svn/text-base/manual-sprop.rkt.svn-base
+     -/private/.svn/text-base/manual-style.rkt.svn-base
+     -/private/.svn/text-base/manual-tech.rkt.svn-base
+     -/private/.svn/text-base/manual-unit.rkt.svn-base
+     -/private/.svn/text-base/manual-utils.rkt.svn-base
+     -/private/.svn/text-base/manual-vars.rkt.svn-base
+     -/private/.svn/text-base/on-demand.rkt.svn-base
+     -/private/.svn/text-base/provide-structs.rkt.svn-base
+     -/private/.svn/text-base/qsloc.rkt.svn-base
+     -/private/.svn/text-base/render-utils.rkt.svn-base
+     -/private/.svn/text-base/run-pdflatex.rkt.svn-base
      -/private/.svn/tmp/
      -/private/.svn/tmp/prop-base/
      -/private/.svn/tmp/props/
@@ -1253,35 +1253,35 @@
      -/private/compiled/render-utils_ss.zo
      -/private/compiled/run-pdflatex_ss.dep
      -/private/compiled/run-pdflatex_ss.zo
-     -/private/defaults.ss
-     -/private/indirect-renderer.ss
-     -/private/lp.ss
-     -/private/manual-bib.ss
-     -/private/manual-bind.ss
-     -/private/manual-class.ss
-     -/private/manual-ex.ss
-     -/private/manual-form.ss
-     -/private/manual-method.ss
-     -/private/manual-mod.ss
-     -/private/manual-proc.ss
-     -/private/manual-scheme.ss
-     -/private/manual-sprop.ss
-     -/private/manual-style.ss
-     -/private/manual-tech.ss
-     -/private/manual-unit.ss
-     -/private/manual-utils.ss
-     -/private/manual-vars.ss
-     -/private/on-demand.ss
-     -/private/provide-structs.ss
-     -/private/qsloc.ss
-     -/private/render-utils.ss
-     -/private/run-pdflatex.ss
-     -/provide-doc-transform.ss
-     -/reader.ss
-     -/render-struct.ss
-     -/run.ss
+     -/private/defaults.rkt
+     -/private/indirect-renderer.rkt
+     -/private/lp.rkt
+     -/private/manual-bib.rkt
+     -/private/manual-bind.rkt
+     -/private/manual-class.rkt
+     -/private/manual-ex.rkt
+     -/private/manual-form.rkt
+     -/private/manual-method.rkt
+     -/private/manual-mod.rkt
+     -/private/manual-proc.rkt
+     -/private/manual-scheme.rkt
+     -/private/manual-sprop.rkt
+     -/private/manual-style.rkt
+     -/private/manual-tech.rkt
+     -/private/manual-unit.rkt
+     -/private/manual-utils.rkt
+     -/private/manual-vars.rkt
+     -/private/on-demand.rkt
+     -/private/provide-structs.rkt
+     -/private/qsloc.rkt
+     -/private/render-utils.rkt
+     -/private/run-pdflatex.rkt
+     -/provide-doc-transform.rkt
+     -/reader.rkt
+     -/render-struct.rkt
+     -/run.rkt
      -/scheme.css
-     -/scheme.ss
+     -/scheme.rkt
      -/scheme.tex
      -/scribble-common.js
      -/scribble-prefix.html
@@ -1290,7 +1290,7 @@
      -/scribble-style.tex
      -/scribble.css
      -/scribble.tex
-     -/search.ss
+     -/search.rkt
      -/sigplan/
      -/sigplan/.svn/
      -/sigplan/.svn/all-wcprops
@@ -1298,14 +1298,14 @@
      -/sigplan/.svn/entries
      -/sigplan/.svn/format
      -/sigplan/.svn/prop-base/
-     -/sigplan/.svn/prop-base/lang.ss.svn-base
+     -/sigplan/.svn/prop-base/lang.rkt.svn-base
      -/sigplan/.svn/prop-base/sigplan.css.svn-base
      -/sigplan/.svn/prop-base/sigplan.tex.svn-base
      -/sigplan/.svn/prop-base/sigplanconf.cls.svn-base
      -/sigplan/.svn/prop-base/style.tex.svn-base
      -/sigplan/.svn/props/
      -/sigplan/.svn/text-base/
-     -/sigplan/.svn/text-base/lang.ss.svn-base
+     -/sigplan/.svn/text-base/lang.rkt.svn-base
      -/sigplan/.svn/text-base/sigplan.css.svn-base
      -/sigplan/.svn/text-base/sigplan.tex.svn-base
      -/sigplan/.svn/text-base/sigplanconf.cls.svn-base
@@ -1324,10 +1324,10 @@
      -/sigplan/lang/.svn/entries
      -/sigplan/lang/.svn/format
      -/sigplan/lang/.svn/prop-base/
-     -/sigplan/lang/.svn/prop-base/reader.ss.svn-base
+     -/sigplan/lang/.svn/prop-base/reader.rkt.svn-base
      -/sigplan/lang/.svn/props/
      -/sigplan/lang/.svn/text-base/
-     -/sigplan/lang/.svn/text-base/reader.ss.svn-base
+     -/sigplan/lang/.svn/text-base/reader.rkt.svn-base
      -/sigplan/lang/.svn/tmp/
      -/sigplan/lang/.svn/tmp/prop-base/
      -/sigplan/lang/.svn/tmp/props/
@@ -1335,15 +1335,15 @@
      -/sigplan/lang/compiled/
      -/sigplan/lang/compiled/reader_ss.dep
      -/sigplan/lang/compiled/reader_ss.zo
-     -/sigplan/lang/reader.ss
-     -/sigplan/lang.ss
+     -/sigplan/lang/reader.rkt
+     -/sigplan/lang.rkt
      -/sigplan/sigplan.css
      -/sigplan/sigplan.tex
      -/sigplan/sigplanconf.cls
      -/sigplan/style.tex
-     -/sigplan.ss
-     -/srcdoc.ss
-     -/struct.ss
+     -/sigplan.rkt
+     -/srcdoc.rkt
+     -/struct.rkt
      -/text/
      -/text/.svn/
      -/text/.svn/all-wcprops
@@ -1351,14 +1351,14 @@
      -/text/.svn/entries
      -/text/.svn/format
      -/text/.svn/prop-base/
-     -/text/.svn/prop-base/output.ss.svn-base
-     -/text/.svn/prop-base/syntax-utils.ss.svn-base
-     -/text/.svn/prop-base/textlang.ss.svn-base
+     -/text/.svn/prop-base/output.rkt.svn-base
+     -/text/.svn/prop-base/syntax-utils.rkt.svn-base
+     -/text/.svn/prop-base/textlang.rkt.svn-base
      -/text/.svn/props/
      -/text/.svn/text-base/
-     -/text/.svn/text-base/output.ss.svn-base
-     -/text/.svn/text-base/syntax-utils.ss.svn-base
-     -/text/.svn/text-base/textlang.ss.svn-base
+     -/text/.svn/text-base/output.rkt.svn-base
+     -/text/.svn/text-base/syntax-utils.rkt.svn-base
+     -/text/.svn/text-base/textlang.rkt.svn-base
      -/text/.svn/tmp/
      -/text/.svn/tmp/prop-base/
      -/text/.svn/tmp/props/
@@ -1377,10 +1377,10 @@
      -/text/lang/.svn/entries
      -/text/lang/.svn/format
      -/text/lang/.svn/prop-base/
-     -/text/lang/.svn/prop-base/reader.ss.svn-base
+     -/text/lang/.svn/prop-base/reader.rkt.svn-base
      -/text/lang/.svn/props/
      -/text/lang/.svn/text-base/
-     -/text/lang/.svn/text-base/reader.ss.svn-base
+     -/text/lang/.svn/text-base/reader.rkt.svn-base
      -/text/lang/.svn/tmp/
      -/text/lang/.svn/tmp/prop-base/
      -/text/lang/.svn/tmp/props/
@@ -1388,12 +1388,12 @@
      -/text/lang/compiled/
      -/text/lang/compiled/reader_ss.dep
      -/text/lang/compiled/reader_ss.zo
-     -/text/lang/reader.ss
-     -/text/output.ss
-     -/text/syntax-utils.ss
-     -/text/textlang.ss
-     -/text-render.ss
-     -/text.ss
+     -/text/lang/reader.rkt
+     -/text/output.rkt
+     -/text/syntax-utils.rkt
+     -/text/textlang.rkt
+     -/text-render.rkt
+     -/text.rkt
      -/tools/
      -/tools/.svn/
      -/tools/.svn/all-wcprops
@@ -1401,12 +1401,12 @@
      -/tools/.svn/entries
      -/tools/.svn/format
      -/tools/.svn/prop-base/
-     -/tools/.svn/prop-base/drscheme-buttons.ss.svn-base
+     -/tools/.svn/prop-base/drscheme-buttons.rkt.svn-base
      -/tools/.svn/prop-base/html.png.svn-base
      -/tools/.svn/prop-base/pdf.png.svn-base
      -/tools/.svn/props/
      -/tools/.svn/text-base/
-     -/tools/.svn/text-base/drscheme-buttons.ss.svn-base
+     -/tools/.svn/text-base/drscheme-buttons.rkt.svn-base
      -/tools/.svn/text-base/html.png.svn-base
      -/tools/.svn/text-base/pdf.png.svn-base
      -/tools/.svn/tmp/
@@ -1416,7 +1416,7 @@
      -/tools/compiled/
      -/tools/compiled/drscheme-buttons_ss.dep
      -/tools/compiled/drscheme-buttons_ss.zo
-     -/tools/drscheme-buttons.ss
+     -/tools/drscheme-buttons.rkt
      -/tools/html.png
      -/tools/pdf.png
      -/tools/private/
@@ -1426,10 +1426,10 @@
      -/tools/private/.svn/entries
      -/tools/private/.svn/format
      -/tools/private/.svn/prop-base/
-     -/tools/private/.svn/prop-base/mk-drs-bitmaps.ss.svn-base
+     -/tools/private/.svn/prop-base/mk-drs-bitmaps.rkt.svn-base
      -/tools/private/.svn/props/
      -/tools/private/.svn/text-base/
-     -/tools/private/.svn/text-base/mk-drs-bitmaps.ss.svn-base
+     -/tools/private/.svn/text-base/mk-drs-bitmaps.rkt.svn-base
      -/tools/private/.svn/tmp/
      -/tools/private/.svn/tmp/prop-base/
      -/tools/private/.svn/tmp/props/
@@ -1437,9 +1437,9 @@
      -/tools/private/compiled/
      -/tools/private/compiled/mk-drs-bitmaps_ss.dep
      -/tools/private/compiled/mk-drs-bitmaps_ss.zo
-     -/tools/private/mk-drs-bitmaps.ss
-     -/urls.ss
-     -/xref.ss
+     -/tools/private/mk-drs-bitmaps.rkt
+     -/urls.rkt
+     -/xref.rkt
      )
    ;; no immediate files
    (e/filter "*/*")
@@ -1451,37 +1451,37 @@
      -/.svn/entries
      -/.svn/format
      -/.svn/prop-base/
-     -/.svn/prop-base/base-render.ss.svn-base
-     -/.svn/prop-base/base.ss.svn-base
-     -/.svn/prop-base/basic.ss.svn-base
-     -/.svn/prop-base/bnf.ss.svn-base
-     -/.svn/prop-base/comment-reader.ss.svn-base
-     -/.svn/prop-base/config.ss.svn-base
-     -/.svn/prop-base/core.ss.svn-base
-     -/.svn/prop-base/decode-struct.ss.svn-base
-     -/.svn/prop-base/decode.ss.svn-base
+     -/.svn/prop-base/base-render.rkt.svn-base
+     -/.svn/prop-base/base.rkt.svn-base
+     -/.svn/prop-base/basic.rkt.svn-base
+     -/.svn/prop-base/bnf.rkt.svn-base
+     -/.svn/prop-base/comment-reader.rkt.svn-base
+     -/.svn/prop-base/config.rkt.svn-base
+     -/.svn/prop-base/core.rkt.svn-base
+     -/.svn/prop-base/decode-struct.rkt.svn-base
+     -/.svn/prop-base/decode.rkt.svn-base
      -/.svn/prop-base/doc.txt.svn-base
-     -/.svn/prop-base/doclang.ss.svn-base
-     -/.svn/prop-base/eval.ss.svn-base
-     -/.svn/prop-base/extract.ss.svn-base
-     -/.svn/prop-base/html-properties.ss.svn-base
-     -/.svn/prop-base/html-render.ss.svn-base
-     -/.svn/prop-base/info.ss.svn-base
-     -/.svn/prop-base/latex-properties.ss.svn-base
-     -/.svn/prop-base/latex-render.ss.svn-base
-     -/.svn/prop-base/lp-include.ss.svn-base
-     -/.svn/prop-base/lp.ss.svn-base
+     -/.svn/prop-base/doclang.rkt.svn-base
+     -/.svn/prop-base/eval.rkt.svn-base
+     -/.svn/prop-base/extract.rkt.svn-base
+     -/.svn/prop-base/html-properties.rkt.svn-base
+     -/.svn/prop-base/html-render.rkt.svn-base
+     -/.svn/prop-base/info.rkt.svn-base
+     -/.svn/prop-base/latex-properties.rkt.svn-base
+     -/.svn/prop-base/latex-render.rkt.svn-base
+     -/.svn/prop-base/lp-include.rkt.svn-base
+     -/.svn/prop-base/lp.rkt.svn-base
      -/.svn/prop-base/manual-prefix.tex.svn-base
-     -/.svn/prop-base/manual-struct.ss.svn-base
+     -/.svn/prop-base/manual-struct.rkt.svn-base
      -/.svn/prop-base/manual-style.tex.svn-base
-     -/.svn/prop-base/manual.ss.svn-base
-     -/.svn/prop-base/pdf-render.ss.svn-base
-     -/.svn/prop-base/provide-doc-transform.ss.svn-base
-     -/.svn/prop-base/reader.ss.svn-base
-     -/.svn/prop-base/render-struct.ss.svn-base
-     -/.svn/prop-base/run.ss.svn-base
+     -/.svn/prop-base/manual.rkt.svn-base
+     -/.svn/prop-base/pdf-render.rkt.svn-base
+     -/.svn/prop-base/provide-doc-transform.rkt.svn-base
+     -/.svn/prop-base/reader.rkt.svn-base
+     -/.svn/prop-base/render-struct.rkt.svn-base
+     -/.svn/prop-base/run.rkt.svn-base
      -/.svn/prop-base/scheme.css.svn-base
-     -/.svn/prop-base/scheme.ss.svn-base
+     -/.svn/prop-base/scheme.rkt.svn-base
      -/.svn/prop-base/scheme.tex.svn-base
      -/.svn/prop-base/scribble-common.js.svn-base
      -/.svn/prop-base/scribble-prefix.html.svn-base
@@ -1490,47 +1490,47 @@
      -/.svn/prop-base/scribble-style.tex.svn-base
      -/.svn/prop-base/scribble.css.svn-base
      -/.svn/prop-base/scribble.tex.svn-base
-     -/.svn/prop-base/search.ss.svn-base
-     -/.svn/prop-base/sigplan.ss.svn-base
-     -/.svn/prop-base/srcdoc.ss.svn-base
-     -/.svn/prop-base/struct.ss.svn-base
-     -/.svn/prop-base/text-render.ss.svn-base
-     -/.svn/prop-base/text.ss.svn-base
-     -/.svn/prop-base/urls.ss.svn-base
-     -/.svn/prop-base/xref.ss.svn-base
+     -/.svn/prop-base/search.rkt.svn-base
+     -/.svn/prop-base/sigplan.rkt.svn-base
+     -/.svn/prop-base/srcdoc.rkt.svn-base
+     -/.svn/prop-base/struct.rkt.svn-base
+     -/.svn/prop-base/text-render.rkt.svn-base
+     -/.svn/prop-base/text.rkt.svn-base
+     -/.svn/prop-base/urls.rkt.svn-base
+     -/.svn/prop-base/xref.rkt.svn-base
      -/.svn/props/
      -/.svn/text-base/
-     -/.svn/text-base/base-render.ss.svn-base
-     -/.svn/text-base/base.ss.svn-base
-     -/.svn/text-base/basic.ss.svn-base
-     -/.svn/text-base/bnf.ss.svn-base
-     -/.svn/text-base/comment-reader.ss.svn-base
-     -/.svn/text-base/config.ss.svn-base
-     -/.svn/text-base/core.ss.svn-base
-     -/.svn/text-base/decode-struct.ss.svn-base
-     -/.svn/text-base/decode.ss.svn-base
+     -/.svn/text-base/base-render.rkt.svn-base
+     -/.svn/text-base/base.rkt.svn-base
+     -/.svn/text-base/basic.rkt.svn-base
+     -/.svn/text-base/bnf.rkt.svn-base
+     -/.svn/text-base/comment-reader.rkt.svn-base
+     -/.svn/text-base/config.rkt.svn-base
+     -/.svn/text-base/core.rkt.svn-base
+     -/.svn/text-base/decode-struct.rkt.svn-base
+     -/.svn/text-base/decode.rkt.svn-base
      -/.svn/text-base/doc.txt.svn-base
-     -/.svn/text-base/doclang.ss.svn-base
-     -/.svn/text-base/eval.ss.svn-base
-     -/.svn/text-base/extract.ss.svn-base
-     -/.svn/text-base/html-properties.ss.svn-base
-     -/.svn/text-base/html-render.ss.svn-base
-     -/.svn/text-base/info.ss.svn-base
-     -/.svn/text-base/latex-properties.ss.svn-base
-     -/.svn/text-base/latex-render.ss.svn-base
-     -/.svn/text-base/lp-include.ss.svn-base
-     -/.svn/text-base/lp.ss.svn-base
+     -/.svn/text-base/doclang.rkt.svn-base
+     -/.svn/text-base/eval.rkt.svn-base
+     -/.svn/text-base/extract.rkt.svn-base
+     -/.svn/text-base/html-properties.rkt.svn-base
+     -/.svn/text-base/html-render.rkt.svn-base
+     -/.svn/text-base/info.rkt.svn-base
+     -/.svn/text-base/latex-properties.rkt.svn-base
+     -/.svn/text-base/latex-render.rkt.svn-base
+     -/.svn/text-base/lp-include.rkt.svn-base
+     -/.svn/text-base/lp.rkt.svn-base
      -/.svn/text-base/manual-prefix.tex.svn-base
-     -/.svn/text-base/manual-struct.ss.svn-base
+     -/.svn/text-base/manual-struct.rkt.svn-base
      -/.svn/text-base/manual-style.tex.svn-base
-     -/.svn/text-base/manual.ss.svn-base
-     -/.svn/text-base/pdf-render.ss.svn-base
-     -/.svn/text-base/provide-doc-transform.ss.svn-base
-     -/.svn/text-base/reader.ss.svn-base
-     -/.svn/text-base/render-struct.ss.svn-base
-     -/.svn/text-base/run.ss.svn-base
+     -/.svn/text-base/manual.rkt.svn-base
+     -/.svn/text-base/pdf-render.rkt.svn-base
+     -/.svn/text-base/provide-doc-transform.rkt.svn-base
+     -/.svn/text-base/reader.rkt.svn-base
+     -/.svn/text-base/render-struct.rkt.svn-base
+     -/.svn/text-base/run.rkt.svn-base
      -/.svn/text-base/scheme.css.svn-base
-     -/.svn/text-base/scheme.ss.svn-base
+     -/.svn/text-base/scheme.rkt.svn-base
      -/.svn/text-base/scheme.tex.svn-base
      -/.svn/text-base/scribble-common.js.svn-base
      -/.svn/text-base/scribble-prefix.html.svn-base
@@ -1539,14 +1539,14 @@
      -/.svn/text-base/scribble-style.tex.svn-base
      -/.svn/text-base/scribble.css.svn-base
      -/.svn/text-base/scribble.tex.svn-base
-     -/.svn/text-base/search.ss.svn-base
-     -/.svn/text-base/sigplan.ss.svn-base
-     -/.svn/text-base/srcdoc.ss.svn-base
-     -/.svn/text-base/struct.ss.svn-base
-     -/.svn/text-base/text-render.ss.svn-base
-     -/.svn/text-base/text.ss.svn-base
-     -/.svn/text-base/urls.ss.svn-base
-     -/.svn/text-base/xref.ss.svn-base
+     -/.svn/text-base/search.rkt.svn-base
+     -/.svn/text-base/sigplan.rkt.svn-base
+     -/.svn/text-base/srcdoc.rkt.svn-base
+     -/.svn/text-base/struct.rkt.svn-base
+     -/.svn/text-base/text-render.rkt.svn-base
+     -/.svn/text-base/text.rkt.svn-base
+     -/.svn/text-base/urls.rkt.svn-base
+     -/.svn/text-base/xref.rkt.svn-base
      -/.svn/tmp/
      -/.svn/tmp/prop-base/
      -/.svn/tmp/props/
@@ -1558,10 +1558,10 @@
      -/base/.svn/entries
      -/base/.svn/format
      -/base/.svn/prop-base/
-     -/base/.svn/prop-base/lang.ss.svn-base
+     -/base/.svn/prop-base/lang.rkt.svn-base
      -/base/.svn/props/
      -/base/.svn/text-base/
-     -/base/.svn/text-base/lang.ss.svn-base
+     -/base/.svn/text-base/lang.rkt.svn-base
      -/base/.svn/tmp/
      -/base/.svn/tmp/prop-base/
      -/base/.svn/tmp/props/
@@ -1576,10 +1576,10 @@
      -/base/lang/.svn/entries
      -/base/lang/.svn/format
      -/base/lang/.svn/prop-base/
-     -/base/lang/.svn/prop-base/reader.ss.svn-base
+     -/base/lang/.svn/prop-base/reader.rkt.svn-base
      -/base/lang/.svn/props/
      -/base/lang/.svn/text-base/
-     -/base/lang/.svn/text-base/reader.ss.svn-base
+     -/base/lang/.svn/text-base/reader.rkt.svn-base
      -/base/lang/.svn/tmp/
      -/base/lang/.svn/tmp/prop-base/
      -/base/lang/.svn/tmp/props/
@@ -1587,8 +1587,8 @@
      -/base/lang/compiled/
      -/base/lang/compiled/reader_ss.dep
      -/base/lang/compiled/reader_ss.zo
-     -/base/lang/reader.ss
-     -/base/lang.ss
+     -/base/lang/reader.rkt
+     -/base/lang.rkt
      -/compiled/
      -/compiled/base-render_ss.dep
      -/compiled/base-render_ss.zo
@@ -1667,12 +1667,12 @@
      -/doc/.svn/entries
      -/doc/.svn/format
      -/doc/.svn/prop-base/
-     -/doc/.svn/prop-base/main.ss.svn-base
-     -/doc/.svn/prop-base/reader.ss.svn-base
+     -/doc/.svn/prop-base/main.rkt.svn-base
+     -/doc/.svn/prop-base/reader.rkt.svn-base
      -/doc/.svn/props/
      -/doc/.svn/text-base/
-     -/doc/.svn/text-base/main.ss.svn-base
-     -/doc/.svn/text-base/reader.ss.svn-base
+     -/doc/.svn/text-base/main.rkt.svn-base
+     -/doc/.svn/text-base/reader.rkt.svn-base
      -/doc/.svn/tmp/
      -/doc/.svn/tmp/prop-base/
      -/doc/.svn/tmp/props/
@@ -1689,10 +1689,10 @@
      -/doc/lang/.svn/entries
      -/doc/lang/.svn/format
      -/doc/lang/.svn/prop-base/
-     -/doc/lang/.svn/prop-base/reader.ss.svn-base
+     -/doc/lang/.svn/prop-base/reader.rkt.svn-base
      -/doc/lang/.svn/props/
      -/doc/lang/.svn/text-base/
-     -/doc/lang/.svn/text-base/reader.ss.svn-base
+     -/doc/lang/.svn/text-base/reader.rkt.svn-base
      -/doc/lang/.svn/tmp/
      -/doc/lang/.svn/tmp/prop-base/
      -/doc/lang/.svn/tmp/props/
@@ -1700,9 +1700,9 @@
      -/doc/lang/compiled/
      -/doc/lang/compiled/reader_ss.dep
      -/doc/lang/compiled/reader_ss.zo
-     -/doc/lang/reader.ss
-     -/doc/main.ss
-     -/doc/reader.ss
+     -/doc/lang/reader.rkt
+     -/doc/main.rkt
+     -/doc/reader.rkt
      -/lp/
      -/lp/.svn/
      -/lp/.svn/all-wcprops
@@ -1722,12 +1722,12 @@
      -/lp/lang/.svn/entries
      -/lp/lang/.svn/format
      -/lp/lang/.svn/prop-base/
-     -/lp/lang/.svn/prop-base/lang.ss.svn-base
-     -/lp/lang/.svn/prop-base/reader.ss.svn-base
+     -/lp/lang/.svn/prop-base/lang.rkt.svn-base
+     -/lp/lang/.svn/prop-base/reader.rkt.svn-base
      -/lp/lang/.svn/props/
      -/lp/lang/.svn/text-base/
-     -/lp/lang/.svn/text-base/lang.ss.svn-base
-     -/lp/lang/.svn/text-base/reader.ss.svn-base
+     -/lp/lang/.svn/text-base/lang.rkt.svn-base
+     -/lp/lang/.svn/text-base/reader.rkt.svn-base
      -/lp/lang/.svn/tmp/
      -/lp/lang/.svn/tmp/prop-base/
      -/lp/lang/.svn/tmp/props/
@@ -1737,8 +1737,8 @@
      -/lp/lang/compiled/lang_ss.zo
      -/lp/lang/compiled/reader_ss.dep
      -/lp/lang/compiled/reader_ss.zo
-     -/lp/lang/lang.ss
-     -/lp/lang/reader.ss
+     -/lp/lang/lang.rkt
+     -/lp/lang/reader.rkt
      -/manual/
      -/manual/.svn/
      -/manual/.svn/all-wcprops
@@ -1746,10 +1746,10 @@
      -/manual/.svn/entries
      -/manual/.svn/format
      -/manual/.svn/prop-base/
-     -/manual/.svn/prop-base/lang.ss.svn-base
+     -/manual/.svn/prop-base/lang.rkt.svn-base
      -/manual/.svn/props/
      -/manual/.svn/text-base/
-     -/manual/.svn/text-base/lang.ss.svn-base
+     -/manual/.svn/text-base/lang.rkt.svn-base
      -/manual/.svn/tmp/
      -/manual/.svn/tmp/prop-base/
      -/manual/.svn/tmp/props/
@@ -1764,10 +1764,10 @@
      -/manual/lang/.svn/entries
      -/manual/lang/.svn/format
      -/manual/lang/.svn/prop-base/
-     -/manual/lang/.svn/prop-base/reader.ss.svn-base
+     -/manual/lang/.svn/prop-base/reader.rkt.svn-base
      -/manual/lang/.svn/props/
      -/manual/lang/.svn/text-base/
-     -/manual/lang/.svn/text-base/reader.ss.svn-base
+     -/manual/lang/.svn/text-base/reader.rkt.svn-base
      -/manual/lang/.svn/tmp/
      -/manual/lang/.svn/tmp/prop-base/
      -/manual/lang/.svn/tmp/props/
@@ -1775,8 +1775,8 @@
      -/manual/lang/compiled/
      -/manual/lang/compiled/reader_ss.dep
      -/manual/lang/compiled/reader_ss.zo
-     -/manual/lang/reader.ss
-     -/manual/lang.ss
+     -/manual/lang/reader.rkt
+     -/manual/lang.rkt
      -/private/
      -/private/.svn/
      -/private/.svn/all-wcprops
@@ -1784,54 +1784,54 @@
      -/private/.svn/entries
      -/private/.svn/format
      -/private/.svn/prop-base/
-     -/private/.svn/prop-base/defaults.ss.svn-base
-     -/private/.svn/prop-base/indirect-renderer.ss.svn-base
-     -/private/.svn/prop-base/lp.ss.svn-base
-     -/private/.svn/prop-base/manual-bib.ss.svn-base
-     -/private/.svn/prop-base/manual-bind.ss.svn-base
-     -/private/.svn/prop-base/manual-class.ss.svn-base
-     -/private/.svn/prop-base/manual-ex.ss.svn-base
-     -/private/.svn/prop-base/manual-form.ss.svn-base
-     -/private/.svn/prop-base/manual-method.ss.svn-base
-     -/private/.svn/prop-base/manual-mod.ss.svn-base
-     -/private/.svn/prop-base/manual-proc.ss.svn-base
-     -/private/.svn/prop-base/manual-scheme.ss.svn-base
-     -/private/.svn/prop-base/manual-sprop.ss.svn-base
-     -/private/.svn/prop-base/manual-style.ss.svn-base
-     -/private/.svn/prop-base/manual-tech.ss.svn-base
-     -/private/.svn/prop-base/manual-unit.ss.svn-base
-     -/private/.svn/prop-base/manual-utils.ss.svn-base
-     -/private/.svn/prop-base/manual-vars.ss.svn-base
-     -/private/.svn/prop-base/on-demand.ss.svn-base
-     -/private/.svn/prop-base/provide-structs.ss.svn-base
-     -/private/.svn/prop-base/qsloc.ss.svn-base
-     -/private/.svn/prop-base/render-utils.ss.svn-base
-     -/private/.svn/prop-base/run-pdflatex.ss.svn-base
+     -/private/.svn/prop-base/defaults.rkt.svn-base
+     -/private/.svn/prop-base/indirect-renderer.rkt.svn-base
+     -/private/.svn/prop-base/lp.rkt.svn-base
+     -/private/.svn/prop-base/manual-bib.rkt.svn-base
+     -/private/.svn/prop-base/manual-bind.rkt.svn-base
+     -/private/.svn/prop-base/manual-class.rkt.svn-base
+     -/private/.svn/prop-base/manual-ex.rkt.svn-base
+     -/private/.svn/prop-base/manual-form.rkt.svn-base
+     -/private/.svn/prop-base/manual-method.rkt.svn-base
+     -/private/.svn/prop-base/manual-mod.rkt.svn-base
+     -/private/.svn/prop-base/manual-proc.rkt.svn-base
+     -/private/.svn/prop-base/manual-scheme.rkt.svn-base
+     -/private/.svn/prop-base/manual-sprop.rkt.svn-base
+     -/private/.svn/prop-base/manual-style.rkt.svn-base
+     -/private/.svn/prop-base/manual-tech.rkt.svn-base
+     -/private/.svn/prop-base/manual-unit.rkt.svn-base
+     -/private/.svn/prop-base/manual-utils.rkt.svn-base
+     -/private/.svn/prop-base/manual-vars.rkt.svn-base
+     -/private/.svn/prop-base/on-demand.rkt.svn-base
+     -/private/.svn/prop-base/provide-structs.rkt.svn-base
+     -/private/.svn/prop-base/qsloc.rkt.svn-base
+     -/private/.svn/prop-base/render-utils.rkt.svn-base
+     -/private/.svn/prop-base/run-pdflatex.rkt.svn-base
      -/private/.svn/props/
      -/private/.svn/text-base/
-     -/private/.svn/text-base/defaults.ss.svn-base
-     -/private/.svn/text-base/indirect-renderer.ss.svn-base
-     -/private/.svn/text-base/lp.ss.svn-base
-     -/private/.svn/text-base/manual-bib.ss.svn-base
-     -/private/.svn/text-base/manual-bind.ss.svn-base
-     -/private/.svn/text-base/manual-class.ss.svn-base
-     -/private/.svn/text-base/manual-ex.ss.svn-base
-     -/private/.svn/text-base/manual-form.ss.svn-base
-     -/private/.svn/text-base/manual-method.ss.svn-base
-     -/private/.svn/text-base/manual-mod.ss.svn-base
-     -/private/.svn/text-base/manual-proc.ss.svn-base
-     -/private/.svn/text-base/manual-scheme.ss.svn-base
-     -/private/.svn/text-base/manual-sprop.ss.svn-base
-     -/private/.svn/text-base/manual-style.ss.svn-base
-     -/private/.svn/text-base/manual-tech.ss.svn-base
-     -/private/.svn/text-base/manual-unit.ss.svn-base
-     -/private/.svn/text-base/manual-utils.ss.svn-base
-     -/private/.svn/text-base/manual-vars.ss.svn-base
-     -/private/.svn/text-base/on-demand.ss.svn-base
-     -/private/.svn/text-base/provide-structs.ss.svn-base
-     -/private/.svn/text-base/qsloc.ss.svn-base
-     -/private/.svn/text-base/render-utils.ss.svn-base
-     -/private/.svn/text-base/run-pdflatex.ss.svn-base
+     -/private/.svn/text-base/defaults.rkt.svn-base
+     -/private/.svn/text-base/indirect-renderer.rkt.svn-base
+     -/private/.svn/text-base/lp.rkt.svn-base
+     -/private/.svn/text-base/manual-bib.rkt.svn-base
+     -/private/.svn/text-base/manual-bind.rkt.svn-base
+     -/private/.svn/text-base/manual-class.rkt.svn-base
+     -/private/.svn/text-base/manual-ex.rkt.svn-base
+     -/private/.svn/text-base/manual-form.rkt.svn-base
+     -/private/.svn/text-base/manual-method.rkt.svn-base
+     -/private/.svn/text-base/manual-mod.rkt.svn-base
+     -/private/.svn/text-base/manual-proc.rkt.svn-base
+     -/private/.svn/text-base/manual-scheme.rkt.svn-base
+     -/private/.svn/text-base/manual-sprop.rkt.svn-base
+     -/private/.svn/text-base/manual-style.rkt.svn-base
+     -/private/.svn/text-base/manual-tech.rkt.svn-base
+     -/private/.svn/text-base/manual-unit.rkt.svn-base
+     -/private/.svn/text-base/manual-utils.rkt.svn-base
+     -/private/.svn/text-base/manual-vars.rkt.svn-base
+     -/private/.svn/text-base/on-demand.rkt.svn-base
+     -/private/.svn/text-base/provide-structs.rkt.svn-base
+     -/private/.svn/text-base/qsloc.rkt.svn-base
+     -/private/.svn/text-base/render-utils.rkt.svn-base
+     -/private/.svn/text-base/run-pdflatex.rkt.svn-base
      -/private/.svn/tmp/
      -/private/.svn/tmp/prop-base/
      -/private/.svn/tmp/props/
@@ -1883,29 +1883,29 @@
      -/private/compiled/render-utils_ss.zo
      -/private/compiled/run-pdflatex_ss.dep
      -/private/compiled/run-pdflatex_ss.zo
-     -/private/defaults.ss
-     -/private/indirect-renderer.ss
-     -/private/lp.ss
-     -/private/manual-bib.ss
-     -/private/manual-bind.ss
-     -/private/manual-class.ss
-     -/private/manual-ex.ss
-     -/private/manual-form.ss
-     -/private/manual-method.ss
-     -/private/manual-mod.ss
-     -/private/manual-proc.ss
-     -/private/manual-scheme.ss
-     -/private/manual-sprop.ss
-     -/private/manual-style.ss
-     -/private/manual-tech.ss
-     -/private/manual-unit.ss
-     -/private/manual-utils.ss
-     -/private/manual-vars.ss
-     -/private/on-demand.ss
-     -/private/provide-structs.ss
-     -/private/qsloc.ss
-     -/private/render-utils.ss
-     -/private/run-pdflatex.ss
+     -/private/defaults.rkt
+     -/private/indirect-renderer.rkt
+     -/private/lp.rkt
+     -/private/manual-bib.rkt
+     -/private/manual-bind.rkt
+     -/private/manual-class.rkt
+     -/private/manual-ex.rkt
+     -/private/manual-form.rkt
+     -/private/manual-method.rkt
+     -/private/manual-mod.rkt
+     -/private/manual-proc.rkt
+     -/private/manual-scheme.rkt
+     -/private/manual-sprop.rkt
+     -/private/manual-style.rkt
+     -/private/manual-tech.rkt
+     -/private/manual-unit.rkt
+     -/private/manual-utils.rkt
+     -/private/manual-vars.rkt
+     -/private/on-demand.rkt
+     -/private/provide-structs.rkt
+     -/private/qsloc.rkt
+     -/private/render-utils.rkt
+     -/private/run-pdflatex.rkt
      -/sigplan/
      -/sigplan/.svn/
      -/sigplan/.svn/all-wcprops
@@ -1913,14 +1913,14 @@
      -/sigplan/.svn/entries
      -/sigplan/.svn/format
      -/sigplan/.svn/prop-base/
-     -/sigplan/.svn/prop-base/lang.ss.svn-base
+     -/sigplan/.svn/prop-base/lang.rkt.svn-base
      -/sigplan/.svn/prop-base/sigplan.css.svn-base
      -/sigplan/.svn/prop-base/sigplan.tex.svn-base
      -/sigplan/.svn/prop-base/sigplanconf.cls.svn-base
      -/sigplan/.svn/prop-base/style.tex.svn-base
      -/sigplan/.svn/props/
      -/sigplan/.svn/text-base/
-     -/sigplan/.svn/text-base/lang.ss.svn-base
+     -/sigplan/.svn/text-base/lang.rkt.svn-base
      -/sigplan/.svn/text-base/sigplan.css.svn-base
      -/sigplan/.svn/text-base/sigplan.tex.svn-base
      -/sigplan/.svn/text-base/sigplanconf.cls.svn-base
@@ -1939,10 +1939,10 @@
      -/sigplan/lang/.svn/entries
      -/sigplan/lang/.svn/format
      -/sigplan/lang/.svn/prop-base/
-     -/sigplan/lang/.svn/prop-base/reader.ss.svn-base
+     -/sigplan/lang/.svn/prop-base/reader.rkt.svn-base
      -/sigplan/lang/.svn/props/
      -/sigplan/lang/.svn/text-base/
-     -/sigplan/lang/.svn/text-base/reader.ss.svn-base
+     -/sigplan/lang/.svn/text-base/reader.rkt.svn-base
      -/sigplan/lang/.svn/tmp/
      -/sigplan/lang/.svn/tmp/prop-base/
      -/sigplan/lang/.svn/tmp/props/
@@ -1950,8 +1950,8 @@
      -/sigplan/lang/compiled/
      -/sigplan/lang/compiled/reader_ss.dep
      -/sigplan/lang/compiled/reader_ss.zo
-     -/sigplan/lang/reader.ss
-     -/sigplan/lang.ss
+     -/sigplan/lang/reader.rkt
+     -/sigplan/lang.rkt
      -/sigplan/sigplan.css
      -/sigplan/sigplan.tex
      -/sigplan/sigplanconf.cls
@@ -1963,14 +1963,14 @@
      -/text/.svn/entries
      -/text/.svn/format
      -/text/.svn/prop-base/
-     -/text/.svn/prop-base/output.ss.svn-base
-     -/text/.svn/prop-base/syntax-utils.ss.svn-base
-     -/text/.svn/prop-base/textlang.ss.svn-base
+     -/text/.svn/prop-base/output.rkt.svn-base
+     -/text/.svn/prop-base/syntax-utils.rkt.svn-base
+     -/text/.svn/prop-base/textlang.rkt.svn-base
      -/text/.svn/props/
      -/text/.svn/text-base/
-     -/text/.svn/text-base/output.ss.svn-base
-     -/text/.svn/text-base/syntax-utils.ss.svn-base
-     -/text/.svn/text-base/textlang.ss.svn-base
+     -/text/.svn/text-base/output.rkt.svn-base
+     -/text/.svn/text-base/syntax-utils.rkt.svn-base
+     -/text/.svn/text-base/textlang.rkt.svn-base
      -/text/.svn/tmp/
      -/text/.svn/tmp/prop-base/
      -/text/.svn/tmp/props/
@@ -1989,10 +1989,10 @@
      -/text/lang/.svn/entries
      -/text/lang/.svn/format
      -/text/lang/.svn/prop-base/
-     -/text/lang/.svn/prop-base/reader.ss.svn-base
+     -/text/lang/.svn/prop-base/reader.rkt.svn-base
      -/text/lang/.svn/props/
      -/text/lang/.svn/text-base/
-     -/text/lang/.svn/text-base/reader.ss.svn-base
+     -/text/lang/.svn/text-base/reader.rkt.svn-base
      -/text/lang/.svn/tmp/
      -/text/lang/.svn/tmp/prop-base/
      -/text/lang/.svn/tmp/props/
@@ -2000,10 +2000,10 @@
      -/text/lang/compiled/
      -/text/lang/compiled/reader_ss.dep
      -/text/lang/compiled/reader_ss.zo
-     -/text/lang/reader.ss
-     -/text/output.ss
-     -/text/syntax-utils.ss
-     -/text/textlang.ss
+     -/text/lang/reader.rkt
+     -/text/output.rkt
+     -/text/syntax-utils.rkt
+     -/text/textlang.rkt
      -/tools/
      -/tools/.svn/
      -/tools/.svn/all-wcprops
@@ -2011,12 +2011,12 @@
      -/tools/.svn/entries
      -/tools/.svn/format
      -/tools/.svn/prop-base/
-     -/tools/.svn/prop-base/drscheme-buttons.ss.svn-base
+     -/tools/.svn/prop-base/drscheme-buttons.rkt.svn-base
      -/tools/.svn/prop-base/html.png.svn-base
      -/tools/.svn/prop-base/pdf.png.svn-base
      -/tools/.svn/props/
      -/tools/.svn/text-base/
-     -/tools/.svn/text-base/drscheme-buttons.ss.svn-base
+     -/tools/.svn/text-base/drscheme-buttons.rkt.svn-base
      -/tools/.svn/text-base/html.png.svn-base
      -/tools/.svn/text-base/pdf.png.svn-base
      -/tools/.svn/tmp/
@@ -2026,7 +2026,7 @@
      -/tools/compiled/
      -/tools/compiled/drscheme-buttons_ss.dep
      -/tools/compiled/drscheme-buttons_ss.zo
-     -/tools/drscheme-buttons.ss
+     -/tools/drscheme-buttons.rkt
      -/tools/html.png
      -/tools/pdf.png
      -/tools/private/
@@ -2036,10 +2036,10 @@
      -/tools/private/.svn/entries
      -/tools/private/.svn/format
      -/tools/private/.svn/prop-base/
-     -/tools/private/.svn/prop-base/mk-drs-bitmaps.ss.svn-base
+     -/tools/private/.svn/prop-base/mk-drs-bitmaps.rkt.svn-base
      -/tools/private/.svn/props/
      -/tools/private/.svn/text-base/
-     -/tools/private/.svn/text-base/mk-drs-bitmaps.ss.svn-base
+     -/tools/private/.svn/text-base/mk-drs-bitmaps.rkt.svn-base
      -/tools/private/.svn/tmp/
      -/tools/private/.svn/tmp/prop-base/
      -/tools/private/.svn/tmp/props/
@@ -2047,7 +2047,7 @@
      -/tools/private/compiled/
      -/tools/private/compiled/mk-drs-bitmaps_ss.dep
      -/tools/private/compiled/mk-drs-bitmaps_ss.zo
-     -/tools/private/mk-drs-bitmaps.ss
+     -/tools/private/mk-drs-bitmaps.rkt
      )
    (e/filter "*/")
    => same-as-last-datums
@@ -2057,37 +2057,37 @@
    '(-/
      -/.svn/
      -/.svn/prop-base/
-     -/.svn/prop-base/base-render.ss.svn-base
-     -/.svn/prop-base/base.ss.svn-base
-     -/.svn/prop-base/basic.ss.svn-base
-     -/.svn/prop-base/bnf.ss.svn-base
-     -/.svn/prop-base/comment-reader.ss.svn-base
-     -/.svn/prop-base/config.ss.svn-base
-     -/.svn/prop-base/core.ss.svn-base
-     -/.svn/prop-base/decode-struct.ss.svn-base
-     -/.svn/prop-base/decode.ss.svn-base
+     -/.svn/prop-base/base-render.rkt.svn-base
+     -/.svn/prop-base/base.rkt.svn-base
+     -/.svn/prop-base/basic.rkt.svn-base
+     -/.svn/prop-base/bnf.rkt.svn-base
+     -/.svn/prop-base/comment-reader.rkt.svn-base
+     -/.svn/prop-base/config.rkt.svn-base
+     -/.svn/prop-base/core.rkt.svn-base
+     -/.svn/prop-base/decode-struct.rkt.svn-base
+     -/.svn/prop-base/decode.rkt.svn-base
      -/.svn/prop-base/doc.txt.svn-base
-     -/.svn/prop-base/doclang.ss.svn-base
-     -/.svn/prop-base/eval.ss.svn-base
-     -/.svn/prop-base/extract.ss.svn-base
-     -/.svn/prop-base/html-properties.ss.svn-base
-     -/.svn/prop-base/html-render.ss.svn-base
-     -/.svn/prop-base/info.ss.svn-base
-     -/.svn/prop-base/latex-properties.ss.svn-base
-     -/.svn/prop-base/latex-render.ss.svn-base
-     -/.svn/prop-base/lp-include.ss.svn-base
-     -/.svn/prop-base/lp.ss.svn-base
+     -/.svn/prop-base/doclang.rkt.svn-base
+     -/.svn/prop-base/eval.rkt.svn-base
+     -/.svn/prop-base/extract.rkt.svn-base
+     -/.svn/prop-base/html-properties.rkt.svn-base
+     -/.svn/prop-base/html-render.rkt.svn-base
+     -/.svn/prop-base/info.rkt.svn-base
+     -/.svn/prop-base/latex-properties.rkt.svn-base
+     -/.svn/prop-base/latex-render.rkt.svn-base
+     -/.svn/prop-base/lp-include.rkt.svn-base
+     -/.svn/prop-base/lp.rkt.svn-base
      -/.svn/prop-base/manual-prefix.tex.svn-base
-     -/.svn/prop-base/manual-struct.ss.svn-base
+     -/.svn/prop-base/manual-struct.rkt.svn-base
      -/.svn/prop-base/manual-style.tex.svn-base
-     -/.svn/prop-base/manual.ss.svn-base
-     -/.svn/prop-base/pdf-render.ss.svn-base
-     -/.svn/prop-base/provide-doc-transform.ss.svn-base
-     -/.svn/prop-base/reader.ss.svn-base
-     -/.svn/prop-base/render-struct.ss.svn-base
-     -/.svn/prop-base/run.ss.svn-base
+     -/.svn/prop-base/manual.rkt.svn-base
+     -/.svn/prop-base/pdf-render.rkt.svn-base
+     -/.svn/prop-base/provide-doc-transform.rkt.svn-base
+     -/.svn/prop-base/reader.rkt.svn-base
+     -/.svn/prop-base/render-struct.rkt.svn-base
+     -/.svn/prop-base/run.rkt.svn-base
      -/.svn/prop-base/scheme.css.svn-base
-     -/.svn/prop-base/scheme.ss.svn-base
+     -/.svn/prop-base/scheme.rkt.svn-base
      -/.svn/prop-base/scheme.tex.svn-base
      -/.svn/prop-base/scribble-common.js.svn-base
      -/.svn/prop-base/scribble-prefix.html.svn-base
@@ -2096,46 +2096,46 @@
      -/.svn/prop-base/scribble-style.tex.svn-base
      -/.svn/prop-base/scribble.css.svn-base
      -/.svn/prop-base/scribble.tex.svn-base
-     -/.svn/prop-base/search.ss.svn-base
-     -/.svn/prop-base/sigplan.ss.svn-base
-     -/.svn/prop-base/srcdoc.ss.svn-base
-     -/.svn/prop-base/struct.ss.svn-base
-     -/.svn/prop-base/text-render.ss.svn-base
-     -/.svn/prop-base/text.ss.svn-base
-     -/.svn/prop-base/urls.ss.svn-base
-     -/.svn/prop-base/xref.ss.svn-base
+     -/.svn/prop-base/search.rkt.svn-base
+     -/.svn/prop-base/sigplan.rkt.svn-base
+     -/.svn/prop-base/srcdoc.rkt.svn-base
+     -/.svn/prop-base/struct.rkt.svn-base
+     -/.svn/prop-base/text-render.rkt.svn-base
+     -/.svn/prop-base/text.rkt.svn-base
+     -/.svn/prop-base/urls.rkt.svn-base
+     -/.svn/prop-base/xref.rkt.svn-base
      -/.svn/text-base/
-     -/.svn/text-base/base-render.ss.svn-base
-     -/.svn/text-base/base.ss.svn-base
-     -/.svn/text-base/basic.ss.svn-base
-     -/.svn/text-base/bnf.ss.svn-base
-     -/.svn/text-base/comment-reader.ss.svn-base
-     -/.svn/text-base/config.ss.svn-base
-     -/.svn/text-base/core.ss.svn-base
-     -/.svn/text-base/decode-struct.ss.svn-base
-     -/.svn/text-base/decode.ss.svn-base
+     -/.svn/text-base/base-render.rkt.svn-base
+     -/.svn/text-base/base.rkt.svn-base
+     -/.svn/text-base/basic.rkt.svn-base
+     -/.svn/text-base/bnf.rkt.svn-base
+     -/.svn/text-base/comment-reader.rkt.svn-base
+     -/.svn/text-base/config.rkt.svn-base
+     -/.svn/text-base/core.rkt.svn-base
+     -/.svn/text-base/decode-struct.rkt.svn-base
+     -/.svn/text-base/decode.rkt.svn-base
      -/.svn/text-base/doc.txt.svn-base
-     -/.svn/text-base/doclang.ss.svn-base
-     -/.svn/text-base/eval.ss.svn-base
-     -/.svn/text-base/extract.ss.svn-base
-     -/.svn/text-base/html-properties.ss.svn-base
-     -/.svn/text-base/html-render.ss.svn-base
-     -/.svn/text-base/info.ss.svn-base
-     -/.svn/text-base/latex-properties.ss.svn-base
-     -/.svn/text-base/latex-render.ss.svn-base
-     -/.svn/text-base/lp-include.ss.svn-base
-     -/.svn/text-base/lp.ss.svn-base
+     -/.svn/text-base/doclang.rkt.svn-base
+     -/.svn/text-base/eval.rkt.svn-base
+     -/.svn/text-base/extract.rkt.svn-base
+     -/.svn/text-base/html-properties.rkt.svn-base
+     -/.svn/text-base/html-render.rkt.svn-base
+     -/.svn/text-base/info.rkt.svn-base
+     -/.svn/text-base/latex-properties.rkt.svn-base
+     -/.svn/text-base/latex-render.rkt.svn-base
+     -/.svn/text-base/lp-include.rkt.svn-base
+     -/.svn/text-base/lp.rkt.svn-base
      -/.svn/text-base/manual-prefix.tex.svn-base
-     -/.svn/text-base/manual-struct.ss.svn-base
+     -/.svn/text-base/manual-struct.rkt.svn-base
      -/.svn/text-base/manual-style.tex.svn-base
-     -/.svn/text-base/manual.ss.svn-base
-     -/.svn/text-base/pdf-render.ss.svn-base
-     -/.svn/text-base/provide-doc-transform.ss.svn-base
-     -/.svn/text-base/reader.ss.svn-base
-     -/.svn/text-base/render-struct.ss.svn-base
-     -/.svn/text-base/run.ss.svn-base
+     -/.svn/text-base/manual.rkt.svn-base
+     -/.svn/text-base/pdf-render.rkt.svn-base
+     -/.svn/text-base/provide-doc-transform.rkt.svn-base
+     -/.svn/text-base/reader.rkt.svn-base
+     -/.svn/text-base/render-struct.rkt.svn-base
+     -/.svn/text-base/run.rkt.svn-base
      -/.svn/text-base/scheme.css.svn-base
-     -/.svn/text-base/scheme.ss.svn-base
+     -/.svn/text-base/scheme.rkt.svn-base
      -/.svn/text-base/scheme.tex.svn-base
      -/.svn/text-base/scribble-common.js.svn-base
      -/.svn/text-base/scribble-prefix.html.svn-base
@@ -2144,14 +2144,14 @@
      -/.svn/text-base/scribble-style.tex.svn-base
      -/.svn/text-base/scribble.css.svn-base
      -/.svn/text-base/scribble.tex.svn-base
-     -/.svn/text-base/search.ss.svn-base
-     -/.svn/text-base/sigplan.ss.svn-base
-     -/.svn/text-base/srcdoc.ss.svn-base
-     -/.svn/text-base/struct.ss.svn-base
-     -/.svn/text-base/text-render.ss.svn-base
-     -/.svn/text-base/text.ss.svn-base
-     -/.svn/text-base/urls.ss.svn-base
-     -/.svn/text-base/xref.ss.svn-base
+     -/.svn/text-base/search.rkt.svn-base
+     -/.svn/text-base/sigplan.rkt.svn-base
+     -/.svn/text-base/srcdoc.rkt.svn-base
+     -/.svn/text-base/struct.rkt.svn-base
+     -/.svn/text-base/text-render.rkt.svn-base
+     -/.svn/text-base/text.rkt.svn-base
+     -/.svn/text-base/urls.rkt.svn-base
+     -/.svn/text-base/xref.rkt.svn-base
      -/.svn/tmp/
      -/.svn/tmp/prop-base/
      -/.svn/tmp/props/
@@ -2163,10 +2163,10 @@
      -/base/.svn/entries
      -/base/.svn/format
      -/base/.svn/prop-base/
-     -/base/.svn/prop-base/lang.ss.svn-base
+     -/base/.svn/prop-base/lang.rkt.svn-base
      -/base/.svn/props/
      -/base/.svn/text-base/
-     -/base/.svn/text-base/lang.ss.svn-base
+     -/base/.svn/text-base/lang.rkt.svn-base
      -/base/.svn/tmp/
      -/base/.svn/tmp/prop-base/
      -/base/.svn/tmp/props/
@@ -2181,10 +2181,10 @@
      -/base/lang/.svn/entries
      -/base/lang/.svn/format
      -/base/lang/.svn/prop-base/
-     -/base/lang/.svn/prop-base/reader.ss.svn-base
+     -/base/lang/.svn/prop-base/reader.rkt.svn-base
      -/base/lang/.svn/props/
      -/base/lang/.svn/text-base/
-     -/base/lang/.svn/text-base/reader.ss.svn-base
+     -/base/lang/.svn/text-base/reader.rkt.svn-base
      -/base/lang/.svn/tmp/
      -/base/lang/.svn/tmp/prop-base/
      -/base/lang/.svn/tmp/props/
@@ -2192,7 +2192,7 @@
      -/base/lang/compiled/
      -/base/lang/compiled/reader_ss.dep
      -/base/lang/compiled/reader_ss.zo
-     -/base/lang/reader.ss
+     -/base/lang/reader.rkt
      -/doc/
      -/doc/.svn/
      -/doc/.svn/all-wcprops
@@ -2200,12 +2200,12 @@
      -/doc/.svn/entries
      -/doc/.svn/format
      -/doc/.svn/prop-base/
-     -/doc/.svn/prop-base/main.ss.svn-base
-     -/doc/.svn/prop-base/reader.ss.svn-base
+     -/doc/.svn/prop-base/main.rkt.svn-base
+     -/doc/.svn/prop-base/reader.rkt.svn-base
      -/doc/.svn/props/
      -/doc/.svn/text-base/
-     -/doc/.svn/text-base/main.ss.svn-base
-     -/doc/.svn/text-base/reader.ss.svn-base
+     -/doc/.svn/text-base/main.rkt.svn-base
+     -/doc/.svn/text-base/reader.rkt.svn-base
      -/doc/.svn/tmp/
      -/doc/.svn/tmp/prop-base/
      -/doc/.svn/tmp/props/
@@ -2222,10 +2222,10 @@
      -/doc/lang/.svn/entries
      -/doc/lang/.svn/format
      -/doc/lang/.svn/prop-base/
-     -/doc/lang/.svn/prop-base/reader.ss.svn-base
+     -/doc/lang/.svn/prop-base/reader.rkt.svn-base
      -/doc/lang/.svn/props/
      -/doc/lang/.svn/text-base/
-     -/doc/lang/.svn/text-base/reader.ss.svn-base
+     -/doc/lang/.svn/text-base/reader.rkt.svn-base
      -/doc/lang/.svn/tmp/
      -/doc/lang/.svn/tmp/prop-base/
      -/doc/lang/.svn/tmp/props/
@@ -2233,7 +2233,7 @@
      -/doc/lang/compiled/
      -/doc/lang/compiled/reader_ss.dep
      -/doc/lang/compiled/reader_ss.zo
-     -/doc/lang/reader.ss
+     -/doc/lang/reader.rkt
      -/lp/
      -/lp/.svn/
      -/lp/.svn/all-wcprops
@@ -2253,12 +2253,12 @@
      -/lp/lang/.svn/entries
      -/lp/lang/.svn/format
      -/lp/lang/.svn/prop-base/
-     -/lp/lang/.svn/prop-base/lang.ss.svn-base
-     -/lp/lang/.svn/prop-base/reader.ss.svn-base
+     -/lp/lang/.svn/prop-base/lang.rkt.svn-base
+     -/lp/lang/.svn/prop-base/reader.rkt.svn-base
      -/lp/lang/.svn/props/
      -/lp/lang/.svn/text-base/
-     -/lp/lang/.svn/text-base/lang.ss.svn-base
-     -/lp/lang/.svn/text-base/reader.ss.svn-base
+     -/lp/lang/.svn/text-base/lang.rkt.svn-base
+     -/lp/lang/.svn/text-base/reader.rkt.svn-base
      -/lp/lang/.svn/tmp/
      -/lp/lang/.svn/tmp/prop-base/
      -/lp/lang/.svn/tmp/props/
@@ -2268,8 +2268,8 @@
      -/lp/lang/compiled/lang_ss.zo
      -/lp/lang/compiled/reader_ss.dep
      -/lp/lang/compiled/reader_ss.zo
-     -/lp/lang/lang.ss
-     -/lp/lang/reader.ss
+     -/lp/lang/lang.rkt
+     -/lp/lang/reader.rkt
      -/manual/
      -/manual/.svn/
      -/manual/.svn/all-wcprops
@@ -2277,10 +2277,10 @@
      -/manual/.svn/entries
      -/manual/.svn/format
      -/manual/.svn/prop-base/
-     -/manual/.svn/prop-base/lang.ss.svn-base
+     -/manual/.svn/prop-base/lang.rkt.svn-base
      -/manual/.svn/props/
      -/manual/.svn/text-base/
-     -/manual/.svn/text-base/lang.ss.svn-base
+     -/manual/.svn/text-base/lang.rkt.svn-base
      -/manual/.svn/tmp/
      -/manual/.svn/tmp/prop-base/
      -/manual/.svn/tmp/props/
@@ -2295,10 +2295,10 @@
      -/manual/lang/.svn/entries
      -/manual/lang/.svn/format
      -/manual/lang/.svn/prop-base/
-     -/manual/lang/.svn/prop-base/reader.ss.svn-base
+     -/manual/lang/.svn/prop-base/reader.rkt.svn-base
      -/manual/lang/.svn/props/
      -/manual/lang/.svn/text-base/
-     -/manual/lang/.svn/text-base/reader.ss.svn-base
+     -/manual/lang/.svn/text-base/reader.rkt.svn-base
      -/manual/lang/.svn/tmp/
      -/manual/lang/.svn/tmp/prop-base/
      -/manual/lang/.svn/tmp/props/
@@ -2306,7 +2306,7 @@
      -/manual/lang/compiled/
      -/manual/lang/compiled/reader_ss.dep
      -/manual/lang/compiled/reader_ss.zo
-     -/manual/lang/reader.ss
+     -/manual/lang/reader.rkt
      -/private/
      -/private/.svn/
      -/private/.svn/all-wcprops
@@ -2314,54 +2314,54 @@
      -/private/.svn/entries
      -/private/.svn/format
      -/private/.svn/prop-base/
-     -/private/.svn/prop-base/defaults.ss.svn-base
-     -/private/.svn/prop-base/indirect-renderer.ss.svn-base
-     -/private/.svn/prop-base/lp.ss.svn-base
-     -/private/.svn/prop-base/manual-bib.ss.svn-base
-     -/private/.svn/prop-base/manual-bind.ss.svn-base
-     -/private/.svn/prop-base/manual-class.ss.svn-base
-     -/private/.svn/prop-base/manual-ex.ss.svn-base
-     -/private/.svn/prop-base/manual-form.ss.svn-base
-     -/private/.svn/prop-base/manual-method.ss.svn-base
-     -/private/.svn/prop-base/manual-mod.ss.svn-base
-     -/private/.svn/prop-base/manual-proc.ss.svn-base
-     -/private/.svn/prop-base/manual-scheme.ss.svn-base
-     -/private/.svn/prop-base/manual-sprop.ss.svn-base
-     -/private/.svn/prop-base/manual-style.ss.svn-base
-     -/private/.svn/prop-base/manual-tech.ss.svn-base
-     -/private/.svn/prop-base/manual-unit.ss.svn-base
-     -/private/.svn/prop-base/manual-utils.ss.svn-base
-     -/private/.svn/prop-base/manual-vars.ss.svn-base
-     -/private/.svn/prop-base/on-demand.ss.svn-base
-     -/private/.svn/prop-base/provide-structs.ss.svn-base
-     -/private/.svn/prop-base/qsloc.ss.svn-base
-     -/private/.svn/prop-base/render-utils.ss.svn-base
-     -/private/.svn/prop-base/run-pdflatex.ss.svn-base
+     -/private/.svn/prop-base/defaults.rkt.svn-base
+     -/private/.svn/prop-base/indirect-renderer.rkt.svn-base
+     -/private/.svn/prop-base/lp.rkt.svn-base
+     -/private/.svn/prop-base/manual-bib.rkt.svn-base
+     -/private/.svn/prop-base/manual-bind.rkt.svn-base
+     -/private/.svn/prop-base/manual-class.rkt.svn-base
+     -/private/.svn/prop-base/manual-ex.rkt.svn-base
+     -/private/.svn/prop-base/manual-form.rkt.svn-base
+     -/private/.svn/prop-base/manual-method.rkt.svn-base
+     -/private/.svn/prop-base/manual-mod.rkt.svn-base
+     -/private/.svn/prop-base/manual-proc.rkt.svn-base
+     -/private/.svn/prop-base/manual-scheme.rkt.svn-base
+     -/private/.svn/prop-base/manual-sprop.rkt.svn-base
+     -/private/.svn/prop-base/manual-style.rkt.svn-base
+     -/private/.svn/prop-base/manual-tech.rkt.svn-base
+     -/private/.svn/prop-base/manual-unit.rkt.svn-base
+     -/private/.svn/prop-base/manual-utils.rkt.svn-base
+     -/private/.svn/prop-base/manual-vars.rkt.svn-base
+     -/private/.svn/prop-base/on-demand.rkt.svn-base
+     -/private/.svn/prop-base/provide-structs.rkt.svn-base
+     -/private/.svn/prop-base/qsloc.rkt.svn-base
+     -/private/.svn/prop-base/render-utils.rkt.svn-base
+     -/private/.svn/prop-base/run-pdflatex.rkt.svn-base
      -/private/.svn/props/
      -/private/.svn/text-base/
-     -/private/.svn/text-base/defaults.ss.svn-base
-     -/private/.svn/text-base/indirect-renderer.ss.svn-base
-     -/private/.svn/text-base/lp.ss.svn-base
-     -/private/.svn/text-base/manual-bib.ss.svn-base
-     -/private/.svn/text-base/manual-bind.ss.svn-base
-     -/private/.svn/text-base/manual-class.ss.svn-base
-     -/private/.svn/text-base/manual-ex.ss.svn-base
-     -/private/.svn/text-base/manual-form.ss.svn-base
-     -/private/.svn/text-base/manual-method.ss.svn-base
-     -/private/.svn/text-base/manual-mod.ss.svn-base
-     -/private/.svn/text-base/manual-proc.ss.svn-base
-     -/private/.svn/text-base/manual-scheme.ss.svn-base
-     -/private/.svn/text-base/manual-sprop.ss.svn-base
-     -/private/.svn/text-base/manual-style.ss.svn-base
-     -/private/.svn/text-base/manual-tech.ss.svn-base
-     -/private/.svn/text-base/manual-unit.ss.svn-base
-     -/private/.svn/text-base/manual-utils.ss.svn-base
-     -/private/.svn/text-base/manual-vars.ss.svn-base
-     -/private/.svn/text-base/on-demand.ss.svn-base
-     -/private/.svn/text-base/provide-structs.ss.svn-base
-     -/private/.svn/text-base/qsloc.ss.svn-base
-     -/private/.svn/text-base/render-utils.ss.svn-base
-     -/private/.svn/text-base/run-pdflatex.ss.svn-base
+     -/private/.svn/text-base/defaults.rkt.svn-base
+     -/private/.svn/text-base/indirect-renderer.rkt.svn-base
+     -/private/.svn/text-base/lp.rkt.svn-base
+     -/private/.svn/text-base/manual-bib.rkt.svn-base
+     -/private/.svn/text-base/manual-bind.rkt.svn-base
+     -/private/.svn/text-base/manual-class.rkt.svn-base
+     -/private/.svn/text-base/manual-ex.rkt.svn-base
+     -/private/.svn/text-base/manual-form.rkt.svn-base
+     -/private/.svn/text-base/manual-method.rkt.svn-base
+     -/private/.svn/text-base/manual-mod.rkt.svn-base
+     -/private/.svn/text-base/manual-proc.rkt.svn-base
+     -/private/.svn/text-base/manual-scheme.rkt.svn-base
+     -/private/.svn/text-base/manual-sprop.rkt.svn-base
+     -/private/.svn/text-base/manual-style.rkt.svn-base
+     -/private/.svn/text-base/manual-tech.rkt.svn-base
+     -/private/.svn/text-base/manual-unit.rkt.svn-base
+     -/private/.svn/text-base/manual-utils.rkt.svn-base
+     -/private/.svn/text-base/manual-vars.rkt.svn-base
+     -/private/.svn/text-base/on-demand.rkt.svn-base
+     -/private/.svn/text-base/provide-structs.rkt.svn-base
+     -/private/.svn/text-base/qsloc.rkt.svn-base
+     -/private/.svn/text-base/render-utils.rkt.svn-base
+     -/private/.svn/text-base/run-pdflatex.rkt.svn-base
      -/private/.svn/tmp/
      -/private/.svn/tmp/prop-base/
      -/private/.svn/tmp/props/
@@ -2420,14 +2420,14 @@
      -/sigplan/.svn/entries
      -/sigplan/.svn/format
      -/sigplan/.svn/prop-base/
-     -/sigplan/.svn/prop-base/lang.ss.svn-base
+     -/sigplan/.svn/prop-base/lang.rkt.svn-base
      -/sigplan/.svn/prop-base/sigplan.css.svn-base
      -/sigplan/.svn/prop-base/sigplan.tex.svn-base
      -/sigplan/.svn/prop-base/sigplanconf.cls.svn-base
      -/sigplan/.svn/prop-base/style.tex.svn-base
      -/sigplan/.svn/props/
      -/sigplan/.svn/text-base/
-     -/sigplan/.svn/text-base/lang.ss.svn-base
+     -/sigplan/.svn/text-base/lang.rkt.svn-base
      -/sigplan/.svn/text-base/sigplan.css.svn-base
      -/sigplan/.svn/text-base/sigplan.tex.svn-base
      -/sigplan/.svn/text-base/sigplanconf.cls.svn-base
@@ -2446,10 +2446,10 @@
      -/sigplan/lang/.svn/entries
      -/sigplan/lang/.svn/format
      -/sigplan/lang/.svn/prop-base/
-     -/sigplan/lang/.svn/prop-base/reader.ss.svn-base
+     -/sigplan/lang/.svn/prop-base/reader.rkt.svn-base
      -/sigplan/lang/.svn/props/
      -/sigplan/lang/.svn/text-base/
-     -/sigplan/lang/.svn/text-base/reader.ss.svn-base
+     -/sigplan/lang/.svn/text-base/reader.rkt.svn-base
      -/sigplan/lang/.svn/tmp/
      -/sigplan/lang/.svn/tmp/prop-base/
      -/sigplan/lang/.svn/tmp/props/
@@ -2457,7 +2457,7 @@
      -/sigplan/lang/compiled/
      -/sigplan/lang/compiled/reader_ss.dep
      -/sigplan/lang/compiled/reader_ss.zo
-     -/sigplan/lang/reader.ss
+     -/sigplan/lang/reader.rkt
      -/text/
      -/text/.svn/
      -/text/.svn/all-wcprops
@@ -2465,14 +2465,14 @@
      -/text/.svn/entries
      -/text/.svn/format
      -/text/.svn/prop-base/
-     -/text/.svn/prop-base/output.ss.svn-base
-     -/text/.svn/prop-base/syntax-utils.ss.svn-base
-     -/text/.svn/prop-base/textlang.ss.svn-base
+     -/text/.svn/prop-base/output.rkt.svn-base
+     -/text/.svn/prop-base/syntax-utils.rkt.svn-base
+     -/text/.svn/prop-base/textlang.rkt.svn-base
      -/text/.svn/props/
      -/text/.svn/text-base/
-     -/text/.svn/text-base/output.ss.svn-base
-     -/text/.svn/text-base/syntax-utils.ss.svn-base
-     -/text/.svn/text-base/textlang.ss.svn-base
+     -/text/.svn/text-base/output.rkt.svn-base
+     -/text/.svn/text-base/syntax-utils.rkt.svn-base
+     -/text/.svn/text-base/textlang.rkt.svn-base
      -/text/.svn/tmp/
      -/text/.svn/tmp/prop-base/
      -/text/.svn/tmp/props/
@@ -2491,10 +2491,10 @@
      -/text/lang/.svn/entries
      -/text/lang/.svn/format
      -/text/lang/.svn/prop-base/
-     -/text/lang/.svn/prop-base/reader.ss.svn-base
+     -/text/lang/.svn/prop-base/reader.rkt.svn-base
      -/text/lang/.svn/props/
      -/text/lang/.svn/text-base/
-     -/text/lang/.svn/text-base/reader.ss.svn-base
+     -/text/lang/.svn/text-base/reader.rkt.svn-base
      -/text/lang/.svn/tmp/
      -/text/lang/.svn/tmp/prop-base/
      -/text/lang/.svn/tmp/props/
@@ -2502,7 +2502,7 @@
      -/text/lang/compiled/
      -/text/lang/compiled/reader_ss.dep
      -/text/lang/compiled/reader_ss.zo
-     -/text/lang/reader.ss
+     -/text/lang/reader.rkt
      -/tools/
      -/tools/.svn/
      -/tools/.svn/all-wcprops
@@ -2510,12 +2510,12 @@
      -/tools/.svn/entries
      -/tools/.svn/format
      -/tools/.svn/prop-base/
-     -/tools/.svn/prop-base/drscheme-buttons.ss.svn-base
+     -/tools/.svn/prop-base/drscheme-buttons.rkt.svn-base
      -/tools/.svn/prop-base/html.png.svn-base
      -/tools/.svn/prop-base/pdf.png.svn-base
      -/tools/.svn/props/
      -/tools/.svn/text-base/
-     -/tools/.svn/text-base/drscheme-buttons.ss.svn-base
+     -/tools/.svn/text-base/drscheme-buttons.rkt.svn-base
      -/tools/.svn/text-base/html.png.svn-base
      -/tools/.svn/text-base/pdf.png.svn-base
      -/tools/.svn/tmp/
@@ -2532,10 +2532,10 @@
      -/tools/private/.svn/entries
      -/tools/private/.svn/format
      -/tools/private/.svn/prop-base/
-     -/tools/private/.svn/prop-base/mk-drs-bitmaps.ss.svn-base
+     -/tools/private/.svn/prop-base/mk-drs-bitmaps.rkt.svn-base
      -/tools/private/.svn/props/
      -/tools/private/.svn/text-base/
-     -/tools/private/.svn/text-base/mk-drs-bitmaps.ss.svn-base
+     -/tools/private/.svn/text-base/mk-drs-bitmaps.rkt.svn-base
      -/tools/private/.svn/tmp/
      -/tools/private/.svn/tmp/prop-base/
      -/tools/private/.svn/tmp/props/
@@ -2543,7 +2543,7 @@
      -/tools/private/compiled/
      -/tools/private/compiled/mk-drs-bitmaps_ss.dep
      -/tools/private/compiled/mk-drs-bitmaps_ss.zo
-     -/tools/private/mk-drs-bitmaps.ss
+     -/tools/private/mk-drs-bitmaps.rkt
      )
    ;; only 3-levels and deeper
    (e/filter "*/*/*/*")
@@ -2552,9 +2552,9 @@
      -/base/
      -/base/.svn/
      -/base/.svn/prop-base/
-     -/base/.svn/prop-base/lang.ss.svn-base
+     -/base/.svn/prop-base/lang.rkt.svn-base
      -/base/.svn/text-base/
-     -/base/.svn/text-base/lang.ss.svn-base
+     -/base/.svn/text-base/lang.rkt.svn-base
      -/base/.svn/tmp/
      -/base/.svn/tmp/prop-base/
      -/base/.svn/tmp/props/
@@ -2566,10 +2566,10 @@
      -/base/lang/.svn/entries
      -/base/lang/.svn/format
      -/base/lang/.svn/prop-base/
-     -/base/lang/.svn/prop-base/reader.ss.svn-base
+     -/base/lang/.svn/prop-base/reader.rkt.svn-base
      -/base/lang/.svn/props/
      -/base/lang/.svn/text-base/
-     -/base/lang/.svn/text-base/reader.ss.svn-base
+     -/base/lang/.svn/text-base/reader.rkt.svn-base
      -/base/lang/.svn/tmp/
      -/base/lang/.svn/tmp/prop-base/
      -/base/lang/.svn/tmp/props/
@@ -2580,11 +2580,11 @@
      -/doc/
      -/doc/.svn/
      -/doc/.svn/prop-base/
-     -/doc/.svn/prop-base/main.ss.svn-base
-     -/doc/.svn/prop-base/reader.ss.svn-base
+     -/doc/.svn/prop-base/main.rkt.svn-base
+     -/doc/.svn/prop-base/reader.rkt.svn-base
      -/doc/.svn/text-base/
-     -/doc/.svn/text-base/main.ss.svn-base
-     -/doc/.svn/text-base/reader.ss.svn-base
+     -/doc/.svn/text-base/main.rkt.svn-base
+     -/doc/.svn/text-base/reader.rkt.svn-base
      -/doc/.svn/tmp/
      -/doc/.svn/tmp/prop-base/
      -/doc/.svn/tmp/props/
@@ -2596,10 +2596,10 @@
      -/doc/lang/.svn/entries
      -/doc/lang/.svn/format
      -/doc/lang/.svn/prop-base/
-     -/doc/lang/.svn/prop-base/reader.ss.svn-base
+     -/doc/lang/.svn/prop-base/reader.rkt.svn-base
      -/doc/lang/.svn/props/
      -/doc/lang/.svn/text-base/
-     -/doc/lang/.svn/text-base/reader.ss.svn-base
+     -/doc/lang/.svn/text-base/reader.rkt.svn-base
      -/doc/lang/.svn/tmp/
      -/doc/lang/.svn/tmp/prop-base/
      -/doc/lang/.svn/tmp/props/
@@ -2620,12 +2620,12 @@
      -/lp/lang/.svn/entries
      -/lp/lang/.svn/format
      -/lp/lang/.svn/prop-base/
-     -/lp/lang/.svn/prop-base/lang.ss.svn-base
-     -/lp/lang/.svn/prop-base/reader.ss.svn-base
+     -/lp/lang/.svn/prop-base/lang.rkt.svn-base
+     -/lp/lang/.svn/prop-base/reader.rkt.svn-base
      -/lp/lang/.svn/props/
      -/lp/lang/.svn/text-base/
-     -/lp/lang/.svn/text-base/lang.ss.svn-base
-     -/lp/lang/.svn/text-base/reader.ss.svn-base
+     -/lp/lang/.svn/text-base/lang.rkt.svn-base
+     -/lp/lang/.svn/text-base/reader.rkt.svn-base
      -/lp/lang/.svn/tmp/
      -/lp/lang/.svn/tmp/prop-base/
      -/lp/lang/.svn/tmp/props/
@@ -2638,9 +2638,9 @@
      -/manual/
      -/manual/.svn/
      -/manual/.svn/prop-base/
-     -/manual/.svn/prop-base/lang.ss.svn-base
+     -/manual/.svn/prop-base/lang.rkt.svn-base
      -/manual/.svn/text-base/
-     -/manual/.svn/text-base/lang.ss.svn-base
+     -/manual/.svn/text-base/lang.rkt.svn-base
      -/manual/.svn/tmp/
      -/manual/.svn/tmp/prop-base/
      -/manual/.svn/tmp/props/
@@ -2652,10 +2652,10 @@
      -/manual/lang/.svn/entries
      -/manual/lang/.svn/format
      -/manual/lang/.svn/prop-base/
-     -/manual/lang/.svn/prop-base/reader.ss.svn-base
+     -/manual/lang/.svn/prop-base/reader.rkt.svn-base
      -/manual/lang/.svn/props/
      -/manual/lang/.svn/text-base/
-     -/manual/lang/.svn/text-base/reader.ss.svn-base
+     -/manual/lang/.svn/text-base/reader.rkt.svn-base
      -/manual/lang/.svn/tmp/
      -/manual/lang/.svn/tmp/prop-base/
      -/manual/lang/.svn/tmp/props/
@@ -2666,53 +2666,53 @@
      -/private/
      -/private/.svn/
      -/private/.svn/prop-base/
-     -/private/.svn/prop-base/defaults.ss.svn-base
-     -/private/.svn/prop-base/indirect-renderer.ss.svn-base
-     -/private/.svn/prop-base/lp.ss.svn-base
-     -/private/.svn/prop-base/manual-bib.ss.svn-base
-     -/private/.svn/prop-base/manual-bind.ss.svn-base
-     -/private/.svn/prop-base/manual-class.ss.svn-base
-     -/private/.svn/prop-base/manual-ex.ss.svn-base
-     -/private/.svn/prop-base/manual-form.ss.svn-base
-     -/private/.svn/prop-base/manual-method.ss.svn-base
-     -/private/.svn/prop-base/manual-mod.ss.svn-base
-     -/private/.svn/prop-base/manual-proc.ss.svn-base
-     -/private/.svn/prop-base/manual-scheme.ss.svn-base
-     -/private/.svn/prop-base/manual-sprop.ss.svn-base
-     -/private/.svn/prop-base/manual-style.ss.svn-base
-     -/private/.svn/prop-base/manual-tech.ss.svn-base
-     -/private/.svn/prop-base/manual-unit.ss.svn-base
-     -/private/.svn/prop-base/manual-utils.ss.svn-base
-     -/private/.svn/prop-base/manual-vars.ss.svn-base
-     -/private/.svn/prop-base/on-demand.ss.svn-base
-     -/private/.svn/prop-base/provide-structs.ss.svn-base
-     -/private/.svn/prop-base/qsloc.ss.svn-base
-     -/private/.svn/prop-base/render-utils.ss.svn-base
-     -/private/.svn/prop-base/run-pdflatex.ss.svn-base
+     -/private/.svn/prop-base/defaults.rkt.svn-base
+     -/private/.svn/prop-base/indirect-renderer.rkt.svn-base
+     -/private/.svn/prop-base/lp.rkt.svn-base
+     -/private/.svn/prop-base/manual-bib.rkt.svn-base
+     -/private/.svn/prop-base/manual-bind.rkt.svn-base
+     -/private/.svn/prop-base/manual-class.rkt.svn-base
+     -/private/.svn/prop-base/manual-ex.rkt.svn-base
+     -/private/.svn/prop-base/manual-form.rkt.svn-base
+     -/private/.svn/prop-base/manual-method.rkt.svn-base
+     -/private/.svn/prop-base/manual-mod.rkt.svn-base
+     -/private/.svn/prop-base/manual-proc.rkt.svn-base
+     -/private/.svn/prop-base/manual-scheme.rkt.svn-base
+     -/private/.svn/prop-base/manual-sprop.rkt.svn-base
+     -/private/.svn/prop-base/manual-style.rkt.svn-base
+     -/private/.svn/prop-base/manual-tech.rkt.svn-base
+     -/private/.svn/prop-base/manual-unit.rkt.svn-base
+     -/private/.svn/prop-base/manual-utils.rkt.svn-base
+     -/private/.svn/prop-base/manual-vars.rkt.svn-base
+     -/private/.svn/prop-base/on-demand.rkt.svn-base
+     -/private/.svn/prop-base/provide-structs.rkt.svn-base
+     -/private/.svn/prop-base/qsloc.rkt.svn-base
+     -/private/.svn/prop-base/render-utils.rkt.svn-base
+     -/private/.svn/prop-base/run-pdflatex.rkt.svn-base
      -/private/.svn/text-base/
-     -/private/.svn/text-base/defaults.ss.svn-base
-     -/private/.svn/text-base/indirect-renderer.ss.svn-base
-     -/private/.svn/text-base/lp.ss.svn-base
-     -/private/.svn/text-base/manual-bib.ss.svn-base
-     -/private/.svn/text-base/manual-bind.ss.svn-base
-     -/private/.svn/text-base/manual-class.ss.svn-base
-     -/private/.svn/text-base/manual-ex.ss.svn-base
-     -/private/.svn/text-base/manual-form.ss.svn-base
-     -/private/.svn/text-base/manual-method.ss.svn-base
-     -/private/.svn/text-base/manual-mod.ss.svn-base
-     -/private/.svn/text-base/manual-proc.ss.svn-base
-     -/private/.svn/text-base/manual-scheme.ss.svn-base
-     -/private/.svn/text-base/manual-sprop.ss.svn-base
-     -/private/.svn/text-base/manual-style.ss.svn-base
-     -/private/.svn/text-base/manual-tech.ss.svn-base
-     -/private/.svn/text-base/manual-unit.ss.svn-base
-     -/private/.svn/text-base/manual-utils.ss.svn-base
-     -/private/.svn/text-base/manual-vars.ss.svn-base
-     -/private/.svn/text-base/on-demand.ss.svn-base
-     -/private/.svn/text-base/provide-structs.ss.svn-base
-     -/private/.svn/text-base/qsloc.ss.svn-base
-     -/private/.svn/text-base/render-utils.ss.svn-base
-     -/private/.svn/text-base/run-pdflatex.ss.svn-base
+     -/private/.svn/text-base/defaults.rkt.svn-base
+     -/private/.svn/text-base/indirect-renderer.rkt.svn-base
+     -/private/.svn/text-base/lp.rkt.svn-base
+     -/private/.svn/text-base/manual-bib.rkt.svn-base
+     -/private/.svn/text-base/manual-bind.rkt.svn-base
+     -/private/.svn/text-base/manual-class.rkt.svn-base
+     -/private/.svn/text-base/manual-ex.rkt.svn-base
+     -/private/.svn/text-base/manual-form.rkt.svn-base
+     -/private/.svn/text-base/manual-method.rkt.svn-base
+     -/private/.svn/text-base/manual-mod.rkt.svn-base
+     -/private/.svn/text-base/manual-proc.rkt.svn-base
+     -/private/.svn/text-base/manual-scheme.rkt.svn-base
+     -/private/.svn/text-base/manual-sprop.rkt.svn-base
+     -/private/.svn/text-base/manual-style.rkt.svn-base
+     -/private/.svn/text-base/manual-tech.rkt.svn-base
+     -/private/.svn/text-base/manual-unit.rkt.svn-base
+     -/private/.svn/text-base/manual-utils.rkt.svn-base
+     -/private/.svn/text-base/manual-vars.rkt.svn-base
+     -/private/.svn/text-base/on-demand.rkt.svn-base
+     -/private/.svn/text-base/provide-structs.rkt.svn-base
+     -/private/.svn/text-base/qsloc.rkt.svn-base
+     -/private/.svn/text-base/render-utils.rkt.svn-base
+     -/private/.svn/text-base/run-pdflatex.rkt.svn-base
      -/private/.svn/tmp/
      -/private/.svn/tmp/prop-base/
      -/private/.svn/tmp/props/
@@ -2720,13 +2720,13 @@
      -/sigplan/
      -/sigplan/.svn/
      -/sigplan/.svn/prop-base/
-     -/sigplan/.svn/prop-base/lang.ss.svn-base
+     -/sigplan/.svn/prop-base/lang.rkt.svn-base
      -/sigplan/.svn/prop-base/sigplan.css.svn-base
      -/sigplan/.svn/prop-base/sigplan.tex.svn-base
      -/sigplan/.svn/prop-base/sigplanconf.cls.svn-base
      -/sigplan/.svn/prop-base/style.tex.svn-base
      -/sigplan/.svn/text-base/
-     -/sigplan/.svn/text-base/lang.ss.svn-base
+     -/sigplan/.svn/text-base/lang.rkt.svn-base
      -/sigplan/.svn/text-base/sigplan.css.svn-base
      -/sigplan/.svn/text-base/sigplan.tex.svn-base
      -/sigplan/.svn/text-base/sigplanconf.cls.svn-base
@@ -2742,10 +2742,10 @@
      -/sigplan/lang/.svn/entries
      -/sigplan/lang/.svn/format
      -/sigplan/lang/.svn/prop-base/
-     -/sigplan/lang/.svn/prop-base/reader.ss.svn-base
+     -/sigplan/lang/.svn/prop-base/reader.rkt.svn-base
      -/sigplan/lang/.svn/props/
      -/sigplan/lang/.svn/text-base/
-     -/sigplan/lang/.svn/text-base/reader.ss.svn-base
+     -/sigplan/lang/.svn/text-base/reader.rkt.svn-base
      -/sigplan/lang/.svn/tmp/
      -/sigplan/lang/.svn/tmp/prop-base/
      -/sigplan/lang/.svn/tmp/props/
@@ -2756,13 +2756,13 @@
      -/text/
      -/text/.svn/
      -/text/.svn/prop-base/
-     -/text/.svn/prop-base/output.ss.svn-base
-     -/text/.svn/prop-base/syntax-utils.ss.svn-base
-     -/text/.svn/prop-base/textlang.ss.svn-base
+     -/text/.svn/prop-base/output.rkt.svn-base
+     -/text/.svn/prop-base/syntax-utils.rkt.svn-base
+     -/text/.svn/prop-base/textlang.rkt.svn-base
      -/text/.svn/text-base/
-     -/text/.svn/text-base/output.ss.svn-base
-     -/text/.svn/text-base/syntax-utils.ss.svn-base
-     -/text/.svn/text-base/textlang.ss.svn-base
+     -/text/.svn/text-base/output.rkt.svn-base
+     -/text/.svn/text-base/syntax-utils.rkt.svn-base
+     -/text/.svn/text-base/textlang.rkt.svn-base
      -/text/.svn/tmp/
      -/text/.svn/tmp/prop-base/
      -/text/.svn/tmp/props/
@@ -2774,10 +2774,10 @@
      -/text/lang/.svn/entries
      -/text/lang/.svn/format
      -/text/lang/.svn/prop-base/
-     -/text/lang/.svn/prop-base/reader.ss.svn-base
+     -/text/lang/.svn/prop-base/reader.rkt.svn-base
      -/text/lang/.svn/props/
      -/text/lang/.svn/text-base/
-     -/text/lang/.svn/text-base/reader.ss.svn-base
+     -/text/lang/.svn/text-base/reader.rkt.svn-base
      -/text/lang/.svn/tmp/
      -/text/lang/.svn/tmp/prop-base/
      -/text/lang/.svn/tmp/props/
@@ -2788,11 +2788,11 @@
      -/tools/
      -/tools/.svn/
      -/tools/.svn/prop-base/
-     -/tools/.svn/prop-base/drscheme-buttons.ss.svn-base
+     -/tools/.svn/prop-base/drscheme-buttons.rkt.svn-base
      -/tools/.svn/prop-base/html.png.svn-base
      -/tools/.svn/prop-base/pdf.png.svn-base
      -/tools/.svn/text-base/
-     -/tools/.svn/text-base/drscheme-buttons.ss.svn-base
+     -/tools/.svn/text-base/drscheme-buttons.rkt.svn-base
      -/tools/.svn/text-base/html.png.svn-base
      -/tools/.svn/text-base/pdf.png.svn-base
      -/tools/.svn/tmp/
@@ -2806,10 +2806,10 @@
      -/tools/private/.svn/entries
      -/tools/private/.svn/format
      -/tools/private/.svn/prop-base/
-     -/tools/private/.svn/prop-base/mk-drs-bitmaps.ss.svn-base
+     -/tools/private/.svn/prop-base/mk-drs-bitmaps.rkt.svn-base
      -/tools/private/.svn/props/
      -/tools/private/.svn/text-base/
-     -/tools/private/.svn/text-base/mk-drs-bitmaps.ss.svn-base
+     -/tools/private/.svn/text-base/mk-drs-bitmaps.rkt.svn-base
      -/tools/private/.svn/tmp/
      -/tools/private/.svn/tmp/prop-base/
      -/tools/private/.svn/tmp/props/
@@ -2826,9 +2826,9 @@
      -/base/lang/
      -/base/lang/.svn/
      -/base/lang/.svn/prop-base/
-     -/base/lang/.svn/prop-base/reader.ss.svn-base
+     -/base/lang/.svn/prop-base/reader.rkt.svn-base
      -/base/lang/.svn/text-base/
-     -/base/lang/.svn/text-base/reader.ss.svn-base
+     -/base/lang/.svn/text-base/reader.rkt.svn-base
      -/base/lang/.svn/tmp/
      -/base/lang/.svn/tmp/prop-base/
      -/base/lang/.svn/tmp/props/
@@ -2837,9 +2837,9 @@
      -/doc/lang/
      -/doc/lang/.svn/
      -/doc/lang/.svn/prop-base/
-     -/doc/lang/.svn/prop-base/reader.ss.svn-base
+     -/doc/lang/.svn/prop-base/reader.rkt.svn-base
      -/doc/lang/.svn/text-base/
-     -/doc/lang/.svn/text-base/reader.ss.svn-base
+     -/doc/lang/.svn/text-base/reader.rkt.svn-base
      -/doc/lang/.svn/tmp/
      -/doc/lang/.svn/tmp/prop-base/
      -/doc/lang/.svn/tmp/props/
@@ -2848,11 +2848,11 @@
      -/lp/lang/
      -/lp/lang/.svn/
      -/lp/lang/.svn/prop-base/
-     -/lp/lang/.svn/prop-base/lang.ss.svn-base
-     -/lp/lang/.svn/prop-base/reader.ss.svn-base
+     -/lp/lang/.svn/prop-base/lang.rkt.svn-base
+     -/lp/lang/.svn/prop-base/reader.rkt.svn-base
      -/lp/lang/.svn/text-base/
-     -/lp/lang/.svn/text-base/lang.ss.svn-base
-     -/lp/lang/.svn/text-base/reader.ss.svn-base
+     -/lp/lang/.svn/text-base/lang.rkt.svn-base
+     -/lp/lang/.svn/text-base/reader.rkt.svn-base
      -/lp/lang/.svn/tmp/
      -/lp/lang/.svn/tmp/prop-base/
      -/lp/lang/.svn/tmp/props/
@@ -2861,9 +2861,9 @@
      -/manual/lang/
      -/manual/lang/.svn/
      -/manual/lang/.svn/prop-base/
-     -/manual/lang/.svn/prop-base/reader.ss.svn-base
+     -/manual/lang/.svn/prop-base/reader.rkt.svn-base
      -/manual/lang/.svn/text-base/
-     -/manual/lang/.svn/text-base/reader.ss.svn-base
+     -/manual/lang/.svn/text-base/reader.rkt.svn-base
      -/manual/lang/.svn/tmp/
      -/manual/lang/.svn/tmp/prop-base/
      -/manual/lang/.svn/tmp/props/
@@ -2872,9 +2872,9 @@
      -/sigplan/lang/
      -/sigplan/lang/.svn/
      -/sigplan/lang/.svn/prop-base/
-     -/sigplan/lang/.svn/prop-base/reader.ss.svn-base
+     -/sigplan/lang/.svn/prop-base/reader.rkt.svn-base
      -/sigplan/lang/.svn/text-base/
-     -/sigplan/lang/.svn/text-base/reader.ss.svn-base
+     -/sigplan/lang/.svn/text-base/reader.rkt.svn-base
      -/sigplan/lang/.svn/tmp/
      -/sigplan/lang/.svn/tmp/prop-base/
      -/sigplan/lang/.svn/tmp/props/
@@ -2883,9 +2883,9 @@
      -/text/lang/
      -/text/lang/.svn/
      -/text/lang/.svn/prop-base/
-     -/text/lang/.svn/prop-base/reader.ss.svn-base
+     -/text/lang/.svn/prop-base/reader.rkt.svn-base
      -/text/lang/.svn/text-base/
-     -/text/lang/.svn/text-base/reader.ss.svn-base
+     -/text/lang/.svn/text-base/reader.rkt.svn-base
      -/text/lang/.svn/tmp/
      -/text/lang/.svn/tmp/prop-base/
      -/text/lang/.svn/tmp/props/
@@ -2894,9 +2894,9 @@
      -/tools/private/
      -/tools/private/.svn/
      -/tools/private/.svn/prop-base/
-     -/tools/private/.svn/prop-base/mk-drs-bitmaps.ss.svn-base
+     -/tools/private/.svn/prop-base/mk-drs-bitmaps.rkt.svn-base
      -/tools/private/.svn/text-base/
-     -/tools/private/.svn/text-base/mk-drs-bitmaps.ss.svn-base
+     -/tools/private/.svn/text-base/mk-drs-bitmaps.rkt.svn-base
      -/tools/private/.svn/tmp/
      -/tools/private/.svn/tmp/prop-base/
      -/tools/private/.svn/tmp/props/
@@ -2915,10 +2915,10 @@
      -/base/lang/
      -/base/lang/.svn/
      -/base/lang/.svn/prop-base/
-     -/base/lang/.svn/prop-base/reader.ss.svn-base
+     -/base/lang/.svn/prop-base/reader.rkt.svn-base
      -/base/lang/.svn/props/
      -/base/lang/.svn/text-base/
-     -/base/lang/.svn/text-base/reader.ss.svn-base
+     -/base/lang/.svn/text-base/reader.rkt.svn-base
      -/base/lang/.svn/tmp/
      -/base/lang/.svn/tmp/prop-base/
      -/base/lang/.svn/tmp/props/
@@ -2932,10 +2932,10 @@
      -/doc/lang/
      -/doc/lang/.svn/
      -/doc/lang/.svn/prop-base/
-     -/doc/lang/.svn/prop-base/reader.ss.svn-base
+     -/doc/lang/.svn/prop-base/reader.rkt.svn-base
      -/doc/lang/.svn/props/
      -/doc/lang/.svn/text-base/
-     -/doc/lang/.svn/text-base/reader.ss.svn-base
+     -/doc/lang/.svn/text-base/reader.rkt.svn-base
      -/doc/lang/.svn/tmp/
      -/doc/lang/.svn/tmp/prop-base/
      -/doc/lang/.svn/tmp/props/
@@ -2949,12 +2949,12 @@
      -/lp/lang/
      -/lp/lang/.svn/
      -/lp/lang/.svn/prop-base/
-     -/lp/lang/.svn/prop-base/lang.ss.svn-base
-     -/lp/lang/.svn/prop-base/reader.ss.svn-base
+     -/lp/lang/.svn/prop-base/lang.rkt.svn-base
+     -/lp/lang/.svn/prop-base/reader.rkt.svn-base
      -/lp/lang/.svn/props/
      -/lp/lang/.svn/text-base/
-     -/lp/lang/.svn/text-base/lang.ss.svn-base
-     -/lp/lang/.svn/text-base/reader.ss.svn-base
+     -/lp/lang/.svn/text-base/lang.rkt.svn-base
+     -/lp/lang/.svn/text-base/reader.rkt.svn-base
      -/lp/lang/.svn/tmp/
      -/lp/lang/.svn/tmp/prop-base/
      -/lp/lang/.svn/tmp/props/
@@ -2968,10 +2968,10 @@
      -/manual/lang/
      -/manual/lang/.svn/
      -/manual/lang/.svn/prop-base/
-     -/manual/lang/.svn/prop-base/reader.ss.svn-base
+     -/manual/lang/.svn/prop-base/reader.rkt.svn-base
      -/manual/lang/.svn/props/
      -/manual/lang/.svn/text-base/
-     -/manual/lang/.svn/text-base/reader.ss.svn-base
+     -/manual/lang/.svn/text-base/reader.rkt.svn-base
      -/manual/lang/.svn/tmp/
      -/manual/lang/.svn/tmp/prop-base/
      -/manual/lang/.svn/tmp/props/
@@ -2991,10 +2991,10 @@
      -/sigplan/lang/
      -/sigplan/lang/.svn/
      -/sigplan/lang/.svn/prop-base/
-     -/sigplan/lang/.svn/prop-base/reader.ss.svn-base
+     -/sigplan/lang/.svn/prop-base/reader.rkt.svn-base
      -/sigplan/lang/.svn/props/
      -/sigplan/lang/.svn/text-base/
-     -/sigplan/lang/.svn/text-base/reader.ss.svn-base
+     -/sigplan/lang/.svn/text-base/reader.rkt.svn-base
      -/sigplan/lang/.svn/tmp/
      -/sigplan/lang/.svn/tmp/prop-base/
      -/sigplan/lang/.svn/tmp/props/
@@ -3008,10 +3008,10 @@
      -/text/lang/
      -/text/lang/.svn/
      -/text/lang/.svn/prop-base/
-     -/text/lang/.svn/prop-base/reader.ss.svn-base
+     -/text/lang/.svn/prop-base/reader.rkt.svn-base
      -/text/lang/.svn/props/
      -/text/lang/.svn/text-base/
-     -/text/lang/.svn/text-base/reader.ss.svn-base
+     -/text/lang/.svn/text-base/reader.rkt.svn-base
      -/text/lang/.svn/tmp/
      -/text/lang/.svn/tmp/prop-base/
      -/text/lang/.svn/tmp/props/
@@ -3025,10 +3025,10 @@
      -/tools/private/
      -/tools/private/.svn/
      -/tools/private/.svn/prop-base/
-     -/tools/private/.svn/prop-base/mk-drs-bitmaps.ss.svn-base
+     -/tools/private/.svn/prop-base/mk-drs-bitmaps.rkt.svn-base
      -/tools/private/.svn/props/
      -/tools/private/.svn/text-base/
-     -/tools/private/.svn/text-base/mk-drs-bitmaps.ss.svn-base
+     -/tools/private/.svn/text-base/mk-drs-bitmaps.rkt.svn-base
      -/tools/private/.svn/tmp/
      -/tools/private/.svn/tmp/prop-base/
      -/tools/private/.svn/tmp/props/
@@ -3044,37 +3044,37 @@
    (e/filter '(not: "*/"))
    =>
    '(-/
-     -/base-render.ss
-     -/base.ss
-     -/basic.ss
-     -/bnf.ss
-     -/comment-reader.ss
-     -/config.ss
-     -/core.ss
-     -/decode-struct.ss
-     -/decode.ss
+     -/base-render.rkt
+     -/base.rkt
+     -/basic.rkt
+     -/bnf.rkt
+     -/comment-reader.rkt
+     -/config.rkt
+     -/core.rkt
+     -/decode-struct.rkt
+     -/decode.rkt
      -/doc.txt
-     -/doclang.ss
-     -/eval.ss
-     -/extract.ss
-     -/html-properties.ss
-     -/html-render.ss
-     -/info.ss
-     -/latex-properties.ss
-     -/latex-render.ss
-     -/lp-include.ss
-     -/lp.ss
+     -/doclang.rkt
+     -/eval.rkt
+     -/extract.rkt
+     -/html-properties.rkt
+     -/html-render.rkt
+     -/info.rkt
+     -/latex-properties.rkt
+     -/latex-render.rkt
+     -/lp-include.rkt
+     -/lp.rkt
      -/manual-prefix.tex
-     -/manual-struct.ss
+     -/manual-struct.rkt
      -/manual-style.tex
-     -/manual.ss
-     -/pdf-render.ss
-     -/provide-doc-transform.ss
-     -/reader.ss
-     -/render-struct.ss
-     -/run.ss
+     -/manual.rkt
+     -/pdf-render.rkt
+     -/provide-doc-transform.rkt
+     -/reader.rkt
+     -/render-struct.rkt
+     -/run.rkt
      -/scheme.css
-     -/scheme.ss
+     -/scheme.rkt
      -/scheme.tex
      -/scribble-common.js
      -/scribble-prefix.html
@@ -3083,14 +3083,14 @@
      -/scribble-style.tex
      -/scribble.css
      -/scribble.tex
-     -/search.ss
-     -/sigplan.ss
-     -/srcdoc.ss
-     -/struct.ss
-     -/text-render.ss
-     -/text.ss
-     -/urls.ss
-     -/xref.ss
+     -/search.rkt
+     -/sigplan.rkt
+     -/srcdoc.rkt
+     -/struct.rkt
+     -/text-render.rkt
+     -/text.rkt
+     -/urls.rkt
+     -/xref.rkt
      )
    ;; (not: "*/*") would be the same as (not: "*/") if empty directories were
    ;; dropped -- but for negated predicates the default is to keep empty
@@ -3102,42 +3102,42 @@
      -/
      -/.svn/
      -/base/
-     -/base-render.ss
-     -/base.ss
-     -/basic.ss
-     -/bnf.ss
-     -/comment-reader.ss
+     -/base-render.rkt
+     -/base.rkt
+     -/basic.rkt
+     -/bnf.rkt
+     -/comment-reader.rkt
      -/compiled/
-     -/config.ss
-     -/core.ss
-     -/decode-struct.ss
-     -/decode.ss
+     -/config.rkt
+     -/core.rkt
+     -/decode-struct.rkt
+     -/decode.rkt
      -/doc/
      -/doc.txt
-     -/doclang.ss
-     -/eval.ss
-     -/extract.ss
-     -/html-properties.ss
-     -/html-render.ss
-     -/info.ss
-     -/latex-properties.ss
-     -/latex-render.ss
+     -/doclang.rkt
+     -/eval.rkt
+     -/extract.rkt
+     -/html-properties.rkt
+     -/html-render.rkt
+     -/info.rkt
+     -/latex-properties.rkt
+     -/latex-render.rkt
      -/lp/
-     -/lp-include.ss
-     -/lp.ss
+     -/lp-include.rkt
+     -/lp.rkt
      -/manual/
      -/manual-prefix.tex
-     -/manual-struct.ss
+     -/manual-struct.rkt
      -/manual-style.tex
-     -/manual.ss
-     -/pdf-render.ss
+     -/manual.rkt
+     -/pdf-render.rkt
      -/private/
-     -/provide-doc-transform.ss
-     -/reader.ss
-     -/render-struct.ss
-     -/run.ss
+     -/provide-doc-transform.rkt
+     -/reader.rkt
+     -/render-struct.rkt
+     -/run.rkt
      -/scheme.css
-     -/scheme.ss
+     -/scheme.rkt
      -/scheme.tex
      -/scribble-common.js
      -/scribble-prefix.html
@@ -3146,17 +3146,17 @@
      -/scribble-style.tex
      -/scribble.css
      -/scribble.tex
-     -/search.ss
+     -/search.rkt
      -/sigplan/
-     -/sigplan.ss
-     -/srcdoc.ss
-     -/struct.ss
+     -/sigplan.rkt
+     -/srcdoc.rkt
+     -/struct.rkt
      -/text/
-     -/text-render.ss
-     -/text.ss
+     -/text-render.rkt
+     -/text.rkt
      -/tools/
-     -/urls.ss
-     -/xref.ss
+     -/urls.rkt
+     -/xref.rkt
      )
    ;; (not: (not: pred)) returns `pred'
    (e/filter '(not: (not: (not: "*/*"))))
@@ -3526,13 +3526,13 @@
      -/base/lang/compiled/
      -/base/lang/compiled/reader_ss.dep
      -/base/lang/compiled/reader_ss.zo
-     -/base/lang/reader.ss
-     -/base/lang.ss
-     -/base-render.ss
-     -/base.ss
-     -/basic.ss
-     -/bnf.ss
-     -/comment-reader.ss
+     -/base/lang/reader.rkt
+     -/base/lang.rkt
+     -/base-render.rkt
+     -/base.rkt
+     -/basic.rkt
+     -/bnf.rkt
+     -/comment-reader.rkt
      -/compiled/
      -/compiled/base-render_ss.dep
      -/compiled/base-render_ss.zo
@@ -3604,10 +3604,10 @@
      -/compiled/urls_ss.zo
      -/compiled/xref_ss.dep
      -/compiled/xref_ss.zo
-     -/config.ss
-     -/core.ss
-     -/decode-struct.ss
-     -/decode.ss
+     -/config.rkt
+     -/core.rkt
+     -/decode-struct.rkt
+     -/decode.rkt
      -/doc/
      -/doc/compiled/
      -/doc/compiled/main_ss.dep
@@ -3618,18 +3618,18 @@
      -/doc/lang/compiled/
      -/doc/lang/compiled/reader_ss.dep
      -/doc/lang/compiled/reader_ss.zo
-     -/doc/lang/reader.ss
-     -/doc/main.ss
-     -/doc/reader.ss
+     -/doc/lang/reader.rkt
+     -/doc/main.rkt
+     -/doc/reader.rkt
      -/doc.txt
-     -/doclang.ss
-     -/eval.ss
-     -/extract.ss
-     -/html-properties.ss
-     -/html-render.ss
-     -/info.ss
-     -/latex-properties.ss
-     -/latex-render.ss
+     -/doclang.rkt
+     -/eval.rkt
+     -/extract.rkt
+     -/html-properties.rkt
+     -/html-render.rkt
+     -/info.rkt
+     -/latex-properties.rkt
+     -/latex-render.rkt
      -/lp/
      -/lp/lang/
      -/lp/lang/compiled/
@@ -3637,10 +3637,10 @@
      -/lp/lang/compiled/lang_ss.zo
      -/lp/lang/compiled/reader_ss.dep
      -/lp/lang/compiled/reader_ss.zo
-     -/lp/lang/lang.ss
-     -/lp/lang/reader.ss
-     -/lp-include.ss
-     -/lp.ss
+     -/lp/lang/lang.rkt
+     -/lp/lang/reader.rkt
+     -/lp-include.rkt
+     -/lp.rkt
      -/manual/
      -/manual/compiled/
      -/manual/compiled/lang_ss.dep
@@ -3649,13 +3649,13 @@
      -/manual/lang/compiled/
      -/manual/lang/compiled/reader_ss.dep
      -/manual/lang/compiled/reader_ss.zo
-     -/manual/lang/reader.ss
-     -/manual/lang.ss
+     -/manual/lang/reader.rkt
+     -/manual/lang.rkt
      -/manual-prefix.tex
-     -/manual-struct.ss
+     -/manual-struct.rkt
      -/manual-style.tex
-     -/manual.ss
-     -/pdf-render.ss
+     -/manual.rkt
+     -/pdf-render.rkt
      -/private/
      -/private/compiled/
      -/private/compiled/defaults_ss.dep
@@ -3704,35 +3704,35 @@
      -/private/compiled/render-utils_ss.zo
      -/private/compiled/run-pdflatex_ss.dep
      -/private/compiled/run-pdflatex_ss.zo
-     -/private/defaults.ss
-     -/private/indirect-renderer.ss
-     -/private/lp.ss
-     -/private/manual-bib.ss
-     -/private/manual-bind.ss
-     -/private/manual-class.ss
-     -/private/manual-ex.ss
-     -/private/manual-form.ss
-     -/private/manual-method.ss
-     -/private/manual-mod.ss
-     -/private/manual-proc.ss
-     -/private/manual-scheme.ss
-     -/private/manual-sprop.ss
-     -/private/manual-style.ss
-     -/private/manual-tech.ss
-     -/private/manual-unit.ss
-     -/private/manual-utils.ss
-     -/private/manual-vars.ss
-     -/private/on-demand.ss
-     -/private/provide-structs.ss
-     -/private/qsloc.ss
-     -/private/render-utils.ss
-     -/private/run-pdflatex.ss
-     -/provide-doc-transform.ss
-     -/reader.ss
-     -/render-struct.ss
-     -/run.ss
+     -/private/defaults.rkt
+     -/private/indirect-renderer.rkt
+     -/private/lp.rkt
+     -/private/manual-bib.rkt
+     -/private/manual-bind.rkt
+     -/private/manual-class.rkt
+     -/private/manual-ex.rkt
+     -/private/manual-form.rkt
+     -/private/manual-method.rkt
+     -/private/manual-mod.rkt
+     -/private/manual-proc.rkt
+     -/private/manual-scheme.rkt
+     -/private/manual-sprop.rkt
+     -/private/manual-style.rkt
+     -/private/manual-tech.rkt
+     -/private/manual-unit.rkt
+     -/private/manual-utils.rkt
+     -/private/manual-vars.rkt
+     -/private/on-demand.rkt
+     -/private/provide-structs.rkt
+     -/private/qsloc.rkt
+     -/private/render-utils.rkt
+     -/private/run-pdflatex.rkt
+     -/provide-doc-transform.rkt
+     -/reader.rkt
+     -/render-struct.rkt
+     -/run.rkt
      -/scheme.css
-     -/scheme.ss
+     -/scheme.rkt
      -/scheme.tex
      -/scribble-common.js
      -/scribble-prefix.html
@@ -3741,7 +3741,7 @@
      -/scribble-style.tex
      -/scribble.css
      -/scribble.tex
-     -/search.ss
+     -/search.rkt
      -/sigplan/
      -/sigplan/compiled/
      -/sigplan/compiled/lang_ss.dep
@@ -3750,15 +3750,15 @@
      -/sigplan/lang/compiled/
      -/sigplan/lang/compiled/reader_ss.dep
      -/sigplan/lang/compiled/reader_ss.zo
-     -/sigplan/lang/reader.ss
-     -/sigplan/lang.ss
+     -/sigplan/lang/reader.rkt
+     -/sigplan/lang.rkt
      -/sigplan/sigplan.css
      -/sigplan/sigplan.tex
      -/sigplan/sigplanconf.cls
      -/sigplan/style.tex
-     -/sigplan.ss
-     -/srcdoc.ss
-     -/struct.ss
+     -/sigplan.rkt
+     -/srcdoc.rkt
+     -/struct.rkt
      -/text/
      -/text/compiled/
      -/text/compiled/output_ss.dep
@@ -3771,26 +3771,26 @@
      -/text/lang/compiled/
      -/text/lang/compiled/reader_ss.dep
      -/text/lang/compiled/reader_ss.zo
-     -/text/lang/reader.ss
-     -/text/output.ss
-     -/text/syntax-utils.ss
-     -/text/textlang.ss
-     -/text-render.ss
-     -/text.ss
+     -/text/lang/reader.rkt
+     -/text/output.rkt
+     -/text/syntax-utils.rkt
+     -/text/textlang.rkt
+     -/text-render.rkt
+     -/text.rkt
      -/tools/
      -/tools/compiled/
      -/tools/compiled/drscheme-buttons_ss.dep
      -/tools/compiled/drscheme-buttons_ss.zo
-     -/tools/drscheme-buttons.ss
+     -/tools/drscheme-buttons.rkt
      -/tools/html.png
      -/tools/pdf.png
      -/tools/private/
      -/tools/private/compiled/
      -/tools/private/compiled/mk-drs-bitmaps_ss.dep
      -/tools/private/compiled/mk-drs-bitmaps_ss.zo
-     -/tools/private/mk-drs-bitmaps.ss
-     -/urls.ss
-     -/xref.ss
+     -/tools/private/mk-drs-bitmaps.rkt
+     -/urls.rkt
+     -/xref.rkt
      )
    ;; no .svn or compiled directories using "{|}"
    (e/filter '(not: "**/{.svn|compiled}/"))
@@ -3798,76 +3798,76 @@
    '(-/
      -/base/
      -/base/lang/
-     -/base/lang/reader.ss
-     -/base/lang.ss
-     -/base-render.ss
-     -/base.ss
-     -/basic.ss
-     -/bnf.ss
-     -/comment-reader.ss
-     -/config.ss
-     -/core.ss
-     -/decode-struct.ss
-     -/decode.ss
+     -/base/lang/reader.rkt
+     -/base/lang.rkt
+     -/base-render.rkt
+     -/base.rkt
+     -/basic.rkt
+     -/bnf.rkt
+     -/comment-reader.rkt
+     -/config.rkt
+     -/core.rkt
+     -/decode-struct.rkt
+     -/decode.rkt
      -/doc/
      -/doc/lang/
-     -/doc/lang/reader.ss
-     -/doc/main.ss
-     -/doc/reader.ss
+     -/doc/lang/reader.rkt
+     -/doc/main.rkt
+     -/doc/reader.rkt
      -/doc.txt
-     -/doclang.ss
-     -/eval.ss
-     -/extract.ss
-     -/html-properties.ss
-     -/html-render.ss
-     -/info.ss
-     -/latex-properties.ss
-     -/latex-render.ss
+     -/doclang.rkt
+     -/eval.rkt
+     -/extract.rkt
+     -/html-properties.rkt
+     -/html-render.rkt
+     -/info.rkt
+     -/latex-properties.rkt
+     -/latex-render.rkt
      -/lp/
      -/lp/lang/
-     -/lp/lang/lang.ss
-     -/lp/lang/reader.ss
-     -/lp-include.ss
-     -/lp.ss
+     -/lp/lang/lang.rkt
+     -/lp/lang/reader.rkt
+     -/lp-include.rkt
+     -/lp.rkt
      -/manual/
      -/manual/lang/
-     -/manual/lang/reader.ss
-     -/manual/lang.ss
+     -/manual/lang/reader.rkt
+     -/manual/lang.rkt
      -/manual-prefix.tex
-     -/manual-struct.ss
+     -/manual-struct.rkt
      -/manual-style.tex
-     -/manual.ss
-     -/pdf-render.ss
+     -/manual.rkt
+     -/pdf-render.rkt
      -/private/
-     -/private/defaults.ss
-     -/private/indirect-renderer.ss
-     -/private/lp.ss
-     -/private/manual-bib.ss
-     -/private/manual-bind.ss
-     -/private/manual-class.ss
-     -/private/manual-ex.ss
-     -/private/manual-form.ss
-     -/private/manual-method.ss
-     -/private/manual-mod.ss
-     -/private/manual-proc.ss
-     -/private/manual-scheme.ss
-     -/private/manual-sprop.ss
-     -/private/manual-style.ss
-     -/private/manual-tech.ss
-     -/private/manual-unit.ss
-     -/private/manual-utils.ss
-     -/private/manual-vars.ss
-     -/private/on-demand.ss
-     -/private/provide-structs.ss
-     -/private/qsloc.ss
-     -/private/render-utils.ss
-     -/private/run-pdflatex.ss
-     -/provide-doc-transform.ss
-     -/reader.ss
-     -/render-struct.ss
-     -/run.ss
+     -/private/defaults.rkt
+     -/private/indirect-renderer.rkt
+     -/private/lp.rkt
+     -/private/manual-bib.rkt
+     -/private/manual-bind.rkt
+     -/private/manual-class.rkt
+     -/private/manual-ex.rkt
+     -/private/manual-form.rkt
+     -/private/manual-method.rkt
+     -/private/manual-mod.rkt
+     -/private/manual-proc.rkt
+     -/private/manual-scheme.rkt
+     -/private/manual-sprop.rkt
+     -/private/manual-style.rkt
+     -/private/manual-tech.rkt
+     -/private/manual-unit.rkt
+     -/private/manual-utils.rkt
+     -/private/manual-vars.rkt
+     -/private/on-demand.rkt
+     -/private/provide-structs.rkt
+     -/private/qsloc.rkt
+     -/private/render-utils.rkt
+     -/private/run-pdflatex.rkt
+     -/provide-doc-transform.rkt
+     -/reader.rkt
+     -/render-struct.rkt
+     -/run.rkt
      -/scheme.css
-     -/scheme.ss
+     -/scheme.rkt
      -/scheme.tex
      -/scribble-common.js
      -/scribble-prefix.html
@@ -3876,34 +3876,34 @@
      -/scribble-style.tex
      -/scribble.css
      -/scribble.tex
-     -/search.ss
+     -/search.rkt
      -/sigplan/
      -/sigplan/lang/
-     -/sigplan/lang/reader.ss
-     -/sigplan/lang.ss
+     -/sigplan/lang/reader.rkt
+     -/sigplan/lang.rkt
      -/sigplan/sigplan.css
      -/sigplan/sigplan.tex
      -/sigplan/sigplanconf.cls
      -/sigplan/style.tex
-     -/sigplan.ss
-     -/srcdoc.ss
-     -/struct.ss
+     -/sigplan.rkt
+     -/srcdoc.rkt
+     -/struct.rkt
      -/text/
      -/text/lang/
-     -/text/lang/reader.ss
-     -/text/output.ss
-     -/text/syntax-utils.ss
-     -/text/textlang.ss
-     -/text-render.ss
-     -/text.ss
+     -/text/lang/reader.rkt
+     -/text/output.rkt
+     -/text/syntax-utils.rkt
+     -/text/textlang.rkt
+     -/text-render.rkt
+     -/text.rkt
      -/tools/
-     -/tools/drscheme-buttons.ss
+     -/tools/drscheme-buttons.rkt
      -/tools/html.png
      -/tools/pdf.png
      -/tools/private/
-     -/tools/private/mk-drs-bitmaps.ss
-     -/urls.ss
-     -/xref.ss
+     -/tools/private/mk-drs-bitmaps.rkt
+     -/urls.rkt
+     -/xref.rkt
      )
    ;; no .svn or compiled directories using `or:'
    (e/filter '(not: (or: "**/.svn/" "**/compiled/")))
diff --git a/collects/meta/web/common/resources.rkt b/collects/meta/web/common/resources.rkt
index fe77cad21d..4445ff5911 100644
--- a/collects/meta/web/common/resources.rkt
+++ b/collects/meta/web/common/resources.rkt
@@ -8,7 +8,7 @@
 ;; resources that are specific to only one site here, do so in the
 ;; site's "resources.rkt" file)
 
-(require "utils.ss")
+(require "utils.rkt")
 
 (provide make-logo make-icon make-style
          navbar-style page-sizes font-family) ; needed for the blog template
diff --git a/collects/mred/edit-main.rkt b/collects/mred/edit-main.rkt
index c9280aae2b..9348904fca 100644
--- a/collects/mred/edit-main.rkt
+++ b/collects/mred/edit-main.rkt
@@ -1,9 +1,9 @@
 
-;; Uses editor.ss to open a frame for each argument
+;; Uses editor.rkt to open a frame for each argument
 
 (module edit-main mzscheme
-  (require "edit.ss"
-	   mzlib/cmdline)
+  (require "edit.rkt"
+           mzlib/cmdline)
 
   (command-line
    "Edit"
diff --git a/collects/mred/main.rkt b/collects/mred/main.rkt
index 65ffc5cc11..e184600892 100644
--- a/collects/mred/main.rkt
+++ b/collects/mred/main.rkt
@@ -1,3 +1,3 @@
 (module main scheme/base
-  (require "mred.ss")
-  (provide (all-from-out "mred.ss")))
+  (require "mred.rkt")
+  (provide (all-from-out "mred.rkt")))
diff --git a/collects/mred/mred-unit.rkt b/collects/mred/mred-unit.rkt
index cfc0ae99c8..324a05a789 100644
--- a/collects/mred/mred-unit.rkt
+++ b/collects/mred/mred-unit.rkt
@@ -1,6 +1,6 @@
 (module mred-unit mzscheme
   (require mzlib/unit
-           "mred-sig.ss"
-           "mred.ss")
+           "mred-sig.rkt"
+           "mred.rkt")
   (provide standard-mred@)
   (define-unit-from-context standard-mred@ mred^))
diff --git a/collects/mred/private/app.rkt b/collects/mred/private/app.rkt
index c546ae878b..73c10f28b8 100644
--- a/collects/mred/private/app.rkt
+++ b/collects/mred/private/app.rkt
@@ -1,18 +1,18 @@
 (module app racket/base
   (require racket/class
-	   (prefix-in wx: "kernel.ss")
-	   "lock.ss"
-	   "helper.ss"
-	   "wx.ss"
-	   "wxtop.ss")
+           (prefix-in wx: "kernel.rkt")
+           "lock.rkt"
+           "helper.rkt"
+           "wx.rkt"
+           "wxtop.rkt")
 
   (provide application-preferences-handler
-	   application-about-handler
-	   application-quit-handler
-	   application-file-handler
-	   current-eventspace-has-standard-menus?
-	   current-eventspace-has-menu-root?
-	   eventspace-handler-thread)
+           application-about-handler
+           application-quit-handler
+           application-file-handler
+           current-eventspace-has-standard-menus?
+           current-eventspace-has-menu-root?
+           eventspace-handler-thread)
 
   ;; An app-handler record keeps a wrapped procedure with
   ;; its original wrappee.
diff --git a/collects/mred/private/check.rkt b/collects/mred/private/check.rkt
index 41d781ce2a..bb5054357e 100644
--- a/collects/mred/private/check.rkt
+++ b/collects/mred/private/check.rkt
@@ -1,8 +1,8 @@
 (module check mzscheme
   (require mzlib/class
-	   (prefix wx: "kernel.ss")
-	   "wx.ss"
-	   "const.ss")
+           (prefix wx: "kernel.rkt")
+           "wx.rkt"
+           "const.rkt")
   (provide (protect (all-defined)))
 
   (define (key-code-symbol? x)
diff --git a/collects/mred/private/const.rkt b/collects/mred/private/const.rkt
index 85f68a167f..6ad5efe963 100644
--- a/collects/mred/private/const.rkt
+++ b/collects/mred/private/const.rkt
@@ -1,8 +1,8 @@
 (module const mzscheme
   (require mzlib/class
-	   mzlib/file
+           mzlib/file
            racket/snip/private/prefs
-	   (prefix wx: "kernel.ss"))
+           (prefix wx: "kernel.rkt"))
   (provide (protect (all-defined)))
 
   ;; default spacing between items.
diff --git a/collects/mred/private/editor.rkt b/collects/mred/private/editor.rkt
index e68b77c969..947ca83128 100644
--- a/collects/mred/private/editor.rkt
+++ b/collects/mred/private/editor.rkt
@@ -1,35 +1,35 @@
 (module editor mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   mzlib/etc
-	   mzlib/list
-	   mzlib/file
-	   (prefix wx: "kernel.ss")
+           mzlib/class100
+           mzlib/etc
+           mzlib/list
+           mzlib/file
+           (prefix wx: "kernel.rkt")
            (prefix wx: racket/snip)
-           (prefix wx: "wxme/keymap.ss")
-           (prefix wx: "wxme/editor.ss")
-           (prefix wx: "wxme/text.ss")
-           (prefix wx: "wxme/pasteboard.ss")
-           (prefix wx: "wxme/editor-snip.ss")
-           (rename "wxme/cycle.ss" wx:set-extended-editor-snip%! set-extended-editor-snip%!)
-           (rename "wxme/cycle.ss" wx:set-extended-text%! set-extended-text%!)
-           (rename "wxme/cycle.ss" wx:set-extended-pasteboard%! set-extended-pasteboard%!)
-	   "seqcontract.ss"
-	   "lock.ss"
-	   "check.ss"
-	   "const.ss"
-	   "helper.ss"
-	   "cycle.ss"
-	   "wx.ss"
-	   "wxtop.ss"
-	   "wxitem.ss"
-	   "wxcanvas.ss"
-	   "mrwindow.ss"
-	   "mrtop.ss"
-	   "mrcanvas.ss"
-	   "mrpopup.ss"
-	   "mrmenuintf.ss"
-	   "mrmenu.ss")
+           (prefix wx: "wxme/keymap.rkt")
+           (prefix wx: "wxme/editor.rkt")
+           (prefix wx: "wxme/text.rkt")
+           (prefix wx: "wxme/pasteboard.rkt")
+           (prefix wx: "wxme/editor-snip.rkt")
+           (rename "wxme/cycle.rkt" wx:set-extended-editor-snip%! set-extended-editor-snip%!)
+           (rename "wxme/cycle.rkt" wx:set-extended-text%! set-extended-text%!)
+           (rename "wxme/cycle.rkt" wx:set-extended-pasteboard%! set-extended-pasteboard%!)
+	   "seqcontract.rkt"
+	   "lock.rkt"
+	   "check.rkt"
+	   "const.rkt"
+	   "helper.rkt"
+	   "cycle.rkt"
+	   "wx.rkt"
+	   "wxtop.rkt"
+	   "wxitem.rkt"
+	   "wxcanvas.rkt"
+	   "mrwindow.rkt"
+	   "mrtop.rkt"
+	   "mrcanvas.rkt"
+	   "mrpopup.rkt"
+	   "mrmenuintf.rkt"
+	   "mrmenu.rkt")
 
   (provide editor<%>
 	   text%
diff --git a/collects/mred/private/filedialog.rkt b/collects/mred/private/filedialog.rkt
index 58630c4b3a..8e74c0d481 100644
--- a/collects/mred/private/filedialog.rkt
+++ b/collects/mred/private/filedialog.rkt
@@ -1,22 +1,22 @@
 (module filedialog mzscheme
   (require mzlib/class
-	   mzlib/etc
-	   mzlib/list
-	   (prefix wx: "kernel.ss")
-	   (prefix wx: racket/snip)
-	   (rename "wxme/cycle.ss" wx:set-editor-get-file! set-editor-get-file!)
-	   (rename "wxme/cycle.ss" wx:set-editor-put-file! set-editor-put-file!)
-	   "lock.ss"
-	   "wx.ss"
-	   "cycle.ss"
-	   "check.ss"
-	   "mrtop.ss"
-	   "path-dialog.ss")
+           mzlib/etc
+           mzlib/list
+           (prefix wx: "kernel.rkt")
+           (prefix wx: racket/snip)
+           (rename "wxme/cycle.rkt" wx:set-editor-get-file! set-editor-get-file!)
+           (rename "wxme/cycle.rkt" wx:set-editor-put-file! set-editor-put-file!)
+           "lock.rkt"
+           "wx.rkt"
+           "cycle.rkt"
+           "check.rkt"
+           "mrtop.rkt"
+           "path-dialog.rkt")
 
   (provide get-file
-	   get-file-list
-	   put-file
-	   get-directory)
+           get-file-list
+           put-file
+           get-directory)
 
   (define (mk-file-selector who put? multi? dir?)
     (lambda (message parent directory filename extension style filters)
diff --git a/collects/mred/private/fontdialog.rkt b/collects/mred/private/fontdialog.rkt
index c8c3795700..636a6d5ea0 100644
--- a/collects/mred/private/fontdialog.rkt
+++ b/collects/mred/private/fontdialog.rkt
@@ -1,22 +1,22 @@
 (module fontdialog mzscheme
   (require mzlib/class
-	   mzlib/etc
-	   mzlib/list
-	   (prefix wx: "kernel.ss")
-	   "lock.ss"
-	   "wx.ss"
-	   "cycle.ss"
-	   "check.ss"
-	   "helper.ss"
-	   "gdi.ss"
-	   "editor.ss"
-	   "mrtop.ss"
-	   "mrcanvas.ss"
-	   "mrpopup.ss"
-	   "mrmenu.ss"
-	   "mritem.ss"
-	   "mrpanel.ss"
-	   "mrtextfield.ss")
+           mzlib/etc
+           mzlib/list
+           (prefix wx: "kernel.rkt")
+           "lock.rkt"
+           "wx.rkt"
+           "cycle.rkt"
+           "check.rkt"
+           "helper.rkt"
+           "gdi.rkt"
+           "editor.rkt"
+           "mrtop.rkt"
+           "mrcanvas.rkt"
+           "mrpopup.rkt"
+           "mrmenu.rkt"
+           "mritem.rkt"
+           "mrpanel.rkt"
+           "mrtextfield.rkt")
 
   (provide get-font-from-user)
 
diff --git a/collects/mred/private/gdi.rkt b/collects/mred/private/gdi.rkt
index db5f75d688..1450792b03 100644
--- a/collects/mred/private/gdi.rkt
+++ b/collects/mred/private/gdi.rkt
@@ -1,16 +1,16 @@
 (module gdi mzscheme
   (require mzlib/class
-	   mzlib/class100
+           mzlib/class100
            mzlib/list
            racket/draw/private/page-dc
-	   (prefix wx: "kernel.ss")
-           (rename "wxme/cycle.ss" wx:set-printer-dc%! set-printer-dc%!)
-	   "lock.ss"
-	   "check.ss"
-	   "wx.ss"
+           (prefix wx: "kernel.rkt")
+           (rename "wxme/cycle.rkt" wx:set-printer-dc%! set-printer-dc%!)
+           "lock.rkt"
+           "check.rkt"
+           "wx.rkt"
            "te.rkt"
-	   "mrtop.ss"
-	   "mrcanvas.ss"
+           "mrtop.rkt"
+           "mrcanvas.rkt"
            "syntax.rkt")
 
   (provide register-collecting-blit
diff --git a/collects/mred/private/helper.rkt b/collects/mred/private/helper.rkt
index e5dcc03720..59466f1527 100644
--- a/collects/mred/private/helper.rkt
+++ b/collects/mred/private/helper.rkt
@@ -1,27 +1,27 @@
 (module helper mzscheme
   (require mzlib/class
-	   (prefix wx: "kernel.ss")
+           (prefix wx: "kernel.rkt")
            (prefix wx: racket/snip)
-	   "lock.ss")
+           "lock.rkt")
 
   (provide (protect (struct child-info (x-min y-min x-margin y-margin x-stretch y-stretch))
-		    get-two-int-values
-		    non-negative-number?
-		    same-dimension?
-		    list-diff
-		    key-regexp
-		    do-command
-		    double-boxed
-		    queue-window-callback
-		    param
-		    protect&
-		    find-pos
-		    no-stretch
-		    font->delta
-		    traverse
-		    object->position
-		    container->children
-		    filter-overlapping
+                    get-two-int-values
+                    non-negative-number?
+                    same-dimension?
+                    list-diff
+                    key-regexp
+                    do-command
+                    double-boxed
+                    queue-window-callback
+                    param
+                    protect&
+                    find-pos
+                    no-stretch
+                    font->delta
+                    traverse
+                    object->position
+                    container->children
+                    filter-overlapping
                     system-position-ok-before-cancel?
                     ok-cancel))
 
diff --git a/collects/mred/private/messagebox.rkt b/collects/mred/private/messagebox.rkt
index e0de7fcabf..a9eb6d09a5 100644
--- a/collects/mred/private/messagebox.rkt
+++ b/collects/mred/private/messagebox.rkt
@@ -1,19 +1,19 @@
 (module messagebox mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   mzlib/etc
+           mzlib/class100
+           mzlib/etc
            mzlib/string
-	   (prefix wx: "kernel.ss")
-	   "const.ss"
-	   "check.ss"
-	   "helper.ss"
-	   "editor.ss"
-	   "mrtop.ss"
-	   "mrcanvas.ss"
-	   "mrpopup.ss"
-	   "mrmenu.ss"
-	   "mritem.ss"
-	   "mrpanel.ss")
+           (prefix wx: "kernel.rkt")
+           "const.rkt"
+           "check.rkt"
+           "helper.rkt"
+           "editor.rkt"
+           "mrtop.rkt"
+           "mrcanvas.rkt"
+           "mrpopup.rkt"
+           "mrmenu.rkt"
+           "mritem.rkt"
+           "mrpanel.rkt")
 
   (provide message-box
 	   message-box/custom
diff --git a/collects/mred/private/misc.rkt b/collects/mred/private/misc.rkt
index c66afbf001..28ea221393 100644
--- a/collects/mred/private/misc.rkt
+++ b/collects/mred/private/misc.rkt
@@ -1,15 +1,15 @@
 (module misc mzscheme
   (require mzlib/class
-	   mzlib/file
-	   mzlib/process
-	   (prefix wx: "kernel.ss")
+           mzlib/file
+           mzlib/process
+           (prefix wx: "kernel.rkt")
            racket/snip/private/prefs)
 
   (provide file-creator-and-type
-	   hide-cursor-until-moved
-	   sleep/yield
-	   play-sound
-	   timer%)
+           hide-cursor-until-moved
+           sleep/yield
+           play-sound
+           timer%)
 
   ;; Formerly used for PS print and preview:
   #;
diff --git a/collects/mred/private/moredialogs.rkt b/collects/mred/private/moredialogs.rkt
index 5373840398..201f620a23 100644
--- a/collects/mred/private/moredialogs.rkt
+++ b/collects/mred/private/moredialogs.rkt
@@ -1,29 +1,29 @@
 (module moredialogs mzscheme
   (require mzlib/class
-	   mzlib/etc
-	   mzlib/list
-	   (prefix wx: "kernel.ss")
-	   (prefix wx: racket/snip)
-	   "lock.ss"
-	   "const.ss"
-	   "check.ss"
-	   "wx.ss"
-	   "helper.ss"
-	   "editor.ss"
-	   "mrtop.ss"
-	   "mrcanvas.ss"
-	   "mrpopup.ss"
-	   "mrmenu.ss"
-	   "mritem.ss"
-	   "mrpanel.ss"
-	   "mrtextfield.ss")
+           mzlib/etc
+           mzlib/list
+           (prefix wx: "kernel.rkt")
+           (prefix wx: racket/snip)
+           "lock.rkt"
+           "const.rkt"
+           "check.rkt"
+           "wx.rkt"
+           "helper.rkt"
+           "editor.rkt"
+           "mrtop.rkt"
+           "mrcanvas.rkt"
+           "mrpopup.rkt"
+           "mrmenu.rkt"
+           "mritem.rkt"
+           "mrpanel.rkt"
+           "mrtextfield.rkt")
 
   (provide get-ps-setup-from-user
-	   get-page-setup-from-user
-	   can-get-page-setup-from-user?
-	   get-text-from-user
-	   get-choices-from-user
-	   get-color-from-user)
+           get-page-setup-from-user
+           can-get-page-setup-from-user?
+           get-text-from-user
+           get-choices-from-user
+           get-color-from-user)
 
   (define (number->string* n)
     (let ([s (number->string n)])
diff --git a/collects/mred/private/mrcanvas.rkt b/collects/mred/private/mrcanvas.rkt
index 796e30f6ea..9871b6bf4a 100644
--- a/collects/mred/private/mrcanvas.rkt
+++ b/collects/mred/private/mrcanvas.rkt
@@ -1,22 +1,22 @@
 (module mrcanvas racket/base
   (require mzlib/class
-	   mzlib/class100
-	   mzlib/list
-	   (prefix-in wx: "kernel.ss")
-	   "lock.ss"
-	   "const.ss"
-	   "kw.ss"
-	   "helper.ss"
-	   "check.ss"
-	   "wx.ss"
-	   "wxcanvas.ss"
-	   "mrwindow.ss"
-	   "mrcontainer.ss"
-	   "mrtop.ss")
+           mzlib/class100
+           mzlib/list
+           (prefix-in wx: "kernel.rkt")
+           "lock.rkt"
+           "const.rkt"
+           "kw.rkt"
+           "helper.rkt"
+           "check.rkt"
+           "wx.rkt"
+           "wxcanvas.rkt"
+           "mrwindow.rkt"
+           "mrcontainer.rkt"
+           "mrtop.rkt")
 
   (provide canvas<%>
-	   canvas%
-	   editor-canvas%)
+           canvas%
+           editor-canvas%)
 
   (define canvas-default-size 20) ; a default size for canvases tht fits borders without losing client sizes
   (define canvas-scroll-size 10)
diff --git a/collects/mred/private/mrcontainer.rkt b/collects/mred/private/mrcontainer.rkt
index 3e21c2ba35..d947ba8297 100644
--- a/collects/mred/private/mrcontainer.rkt
+++ b/collects/mred/private/mrcontainer.rkt
@@ -1,25 +1,25 @@
 (module mrcontainer mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   mzlib/list
-	   (prefix wx: "kernel.ss")
-	   "lock.ss"
-	   "helper.ss"
-	   "const.ss"
-	   "wx.ss"
-	   "kw.ss"
-	   "check.ss"
-	   "wxcontainer.ss"
-	   "mrwindow.ss")
+           mzlib/class100
+           mzlib/list
+           (prefix wx: "kernel.rkt")
+           "lock.rkt"
+           "helper.rkt"
+           "const.rkt"
+           "wx.rkt"
+           "kw.rkt"
+           "check.rkt"
+           "wxcontainer.rkt"
+           "mrwindow.rkt")
 
   (provide area-container<%>
-	   (protect internal-container<%>
-		    check-container-parent
-		    container%-keywords
-		    make-container%
+           (protect internal-container<%>
+                    check-container-parent
+                    container%-keywords
+                    make-container%
                     make-subwindow%)
-	   area-container-window<%>
-	   (protect make-area-container-window%))
+           area-container-window<%>
+           (protect make-area-container-window%))
 
   (define area-container<%> 
     (interface (area<%>) 
diff --git a/collects/mred/private/mred.rkt b/collects/mred/private/mred.rkt
index 47e643be51..9c2215da41 100644
--- a/collects/mred/private/mred.rkt
+++ b/collects/mred/private/mred.rkt
@@ -7,40 +7,40 @@
            racket/draw racket/snip
            file/resource
            mzlib/etc
-	   (prefix wx: "kernel.ss")
-	   (prefix wx: "wxme/editor.ss")
-	   (prefix wx: "wxme/text.ss")
-	   (prefix wx: "wxme/pasteboard.ss")
-	   (prefix wx: "wxme/keymap.ss")
-	   (prefix wx: "wxme/editor-admin.ss")
-           (prefix wx: "wxme/editor-data.ss")
-	   (prefix wx: "wxme/editor-snip.ss")
-	   (prefix wx: "wxme/stream.ss")
-	   (prefix wx: "wxme/wordbreak.ss")
-	   "wxtop.ss"
-	   "app.ss"
-	   "misc.ss"
-	   "mrwindow.ss"
-	   "mrcontainer.ss"
-	   "mrtop.ss"
-	   "mrpanel.ss"
-	   "mrcanvas.ss"
-	   "mritem.ss"
-	   "mrtextfield.ss"
-	   "mrmenuintf.ss"
-	   "mrmenu.ss"
-	   "mrpopup.ss"
-	   "editor.ss"
-	   "messagebox.ss"
-	   "filedialog.ss"
-	   "fontdialog.ss"
-	   "moredialogs.ss"
-	   "gdi.ss"
-	   "snipfile.ss"
-	   "repl.ss"
-           "helper.ss"
-           "dynamic.ss"
-           "check.ss")
+           (prefix wx: "kernel.rkt")
+           (prefix wx: "wxme/editor.rkt")
+           (prefix wx: "wxme/text.rkt")
+           (prefix wx: "wxme/pasteboard.rkt")
+           (prefix wx: "wxme/keymap.rkt")
+           (prefix wx: "wxme/editor-admin.rkt")
+           (prefix wx: "wxme/editor-data.rkt")
+           (prefix wx: "wxme/editor-snip.rkt")
+           (prefix wx: "wxme/stream.rkt")
+           (prefix wx: "wxme/wordbreak.rkt")
+           "wxtop.rkt"
+           "app.rkt"
+           "misc.rkt"
+           "mrwindow.rkt"
+           "mrcontainer.rkt"
+           "mrtop.rkt"
+           "mrpanel.rkt"
+           "mrcanvas.rkt"
+           "mritem.rkt"
+           "mrtextfield.rkt"
+           "mrmenuintf.rkt"
+           "mrmenu.rkt"
+           "mrpopup.rkt"
+           "editor.rkt"
+           "messagebox.rkt"
+           "filedialog.rkt"
+           "fontdialog.rkt"
+           "moredialogs.rkt"
+           "gdi.rkt"
+           "snipfile.rkt"
+           "repl.rkt"
+           "helper.rkt"
+           "dynamic.rkt"
+           "check.rkt")
 
   ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;; These functions are re-implemented in scheme/gui/base
@@ -90,7 +90,7 @@
 			      #f))
 			   ns)])
 	     (syntax (begin
-		       ;; We can't just re-export, because kernel.ss's
+		       ;; We can't just re-export, because kernel.rkt's
 		       ;;  exports are protected.
 		       (define n k:n) ...
 		       (provide n ...)))))])))
diff --git a/collects/mred/private/mritem.rkt b/collects/mred/private/mritem.rkt
index bff01dba81..6ee3f3f745 100644
--- a/collects/mred/private/mritem.rkt
+++ b/collects/mred/private/mritem.rkt
@@ -1,35 +1,35 @@
 (module mritem racket/base
   (require mzlib/class
-	   mzlib/class100
-	   mzlib/list
-	   (prefix-in wx: "kernel.ss")
-	   "lock.ss"
-	   "const.ss"
-	   "kw.ss"
-           "gdi.ss"
-	   "check.ss"
-	   "helper.ss"
-	   "wx.ss"
-	   "wxitem.ss"
-           "wxlitem.ss"
-	   "mrwindow.ss"
-	   "mrcontainer.ss")
+           mzlib/class100
+           mzlib/list
+           (prefix-in wx: "kernel.rkt")
+           "lock.rkt"
+           "const.rkt"
+           "kw.rkt"
+           "gdi.rkt"
+           "check.rkt"
+           "helper.rkt"
+           "wx.rkt"
+           "wxitem.rkt"
+           "wxlitem.rkt"
+           "mrwindow.rkt"
+           "mrcontainer.rkt")
 
   (provide control<%>
-	   (protect-out control%-keywords
+           (protect-out control%-keywords
                         basic-control%)
-	   message%
-	   button%
-	   check-box%
-	   radio-box%
-	   slider%
-	   gauge%
+           message%
+           button%
+           check-box%
+           radio-box%
+           slider%
+           gauge%
 
-	   list-control<%>
-	   choice%
-	   list-box%
+           list-control<%>
+           choice%
+           list-box%
 
-	   (protect-out wrap-callback
+           (protect-out wrap-callback
                         check-list-control-args
                         check-list-control-selection
                         
diff --git a/collects/mred/private/mrmenu.rkt b/collects/mred/private/mrmenu.rkt
index 562b2464ce..0e4eeee0d4 100644
--- a/collects/mred/private/mrmenu.rkt
+++ b/collects/mred/private/mrmenu.rkt
@@ -1,28 +1,28 @@
 (module mrmenu mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   mzlib/list
-	   (prefix wx: "kernel.ss")
-           (prefix wx: "wxme/keymap.ss")
-	   "lock.ss"
-	   "const.ss"
-	   "helper.ss"
-	   "check.ss"
-	   "wx.ss"
-	   "app.ss"
-	   "wxmenu.ss"
-	   "mrtop.ss"
-	   "mrmenuintf.ss"
-	   "mrpopup.ss")
+           mzlib/class100
+           mzlib/list
+           (prefix wx: "kernel.rkt")
+           (prefix wx: "wxme/keymap.rkt")
+           "lock.rkt"
+           "const.rkt"
+           "helper.rkt"
+           "check.rkt"
+           "wx.rkt"
+           "app.rkt"
+           "wxmenu.rkt"
+           "mrtop.rkt"
+           "mrmenuintf.rkt"
+           "mrpopup.rkt")
 
   (provide separator-menu-item%
-	   menu-item%
-	   checkable-menu-item%
-	   menu%
-	   menu-bar%
-	   get-default-shortcut-prefix
-	   (protect menu-parent-only
-		    menu-or-bar-parent))
+           menu-item%
+           checkable-menu-item%
+           menu%
+           menu-bar%
+           get-default-shortcut-prefix
+           (protect menu-parent-only
+                    menu-or-bar-parent))
 
   (define root-menu-frame-used? #f)
 
diff --git a/collects/mred/private/mrpanel.rkt b/collects/mred/private/mrpanel.rkt
index f26a2c805a..c3670d231a 100644
--- a/collects/mred/private/mrpanel.rkt
+++ b/collects/mred/private/mrpanel.rkt
@@ -1,26 +1,26 @@
 (module mrpanel mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   (prefix wx: "kernel.ss")
-	   "lock.ss"
-	   "const.ss"
-	   "check.ss"
-	   "helper.ss"
-	   "wx.ss"
-	   "kw.ss"
-	   "wxpanel.ss"
-	   "mrwindow.ss"
-	   "mrcontainer.ss")
+           mzlib/class100
+           (prefix wx: "kernel.rkt")
+           "lock.rkt"
+           "const.rkt"
+           "check.rkt"
+           "helper.rkt"
+           "wx.rkt"
+           "kw.rkt"
+           "wxpanel.rkt"
+           "mrwindow.rkt"
+           "mrcontainer.rkt")
 
   (provide pane%
-	   vertical-pane%
-	   horizontal-pane%
-	   grow-box-spacer-pane%
-	   panel%
-	   vertical-panel%
-	   horizontal-panel%
-	   tab-panel%
-	   group-box-panel%)
+           vertical-pane%
+           horizontal-pane%
+           grow-box-spacer-pane%
+           panel%
+           vertical-panel%
+           horizontal-panel%
+           tab-panel%
+           group-box-panel%)
 
   (define-keywords pane%-keywords
     subarea%-keywords
diff --git a/collects/mred/private/mrpopup.rkt b/collects/mred/private/mrpopup.rkt
index e977ae01e9..483bf3cfee 100644
--- a/collects/mred/private/mrpopup.rkt
+++ b/collects/mred/private/mrpopup.rkt
@@ -1,16 +1,16 @@
 (module mrpopup mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   mzlib/list
-	   (prefix wx: "kernel.ss")
-           (rename "wxme/cycle.ss" wx:set-popup-menu%! set-popup-menu%!)
-	   "lock.ss"
-	   "const.ss"
-	   "helper.ss"
-	   "check.ss"
-	   "wx.ss"
-	   "wxmenu.ss"
-	   "mrmenuintf.ss")
+           mzlib/class100
+           mzlib/list
+           (prefix wx: "kernel.rkt")
+           (rename "wxme/cycle.rkt" wx:set-popup-menu%! set-popup-menu%!)
+           "lock.rkt"
+           "const.rkt"
+           "helper.rkt"
+           "check.rkt"
+           "wx.rkt"
+           "wxmenu.rkt"
+           "mrmenuintf.rkt")
 
   (provide popup-menu%)
 
diff --git a/collects/mred/private/mrtextfield.rkt b/collects/mred/private/mrtextfield.rkt
index f7d81de5b8..87dbe4ec0e 100644
--- a/collects/mred/private/mrtextfield.rkt
+++ b/collects/mred/private/mrtextfield.rkt
@@ -1,22 +1,22 @@
 (module mrtextfield mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   mzlib/list
-	   (prefix wx: "kernel.ss")
-	   "lock.ss"
-	   "const.ss"
-	   "check.ss"
-	   "helper.ss"
-	   "wx.ss"
-	   "kw.ss"
-	   "wxtextfield.ss"
-	   "mrcontainer.ss"
-	   "mritem.ss"
-	   "mrmenu.ss"
-	   "mrpopup.ss")
+           mzlib/class100
+           mzlib/list
+           (prefix wx: "kernel.rkt")
+           "lock.rkt"
+           "const.rkt"
+           "check.rkt"
+           "helper.rkt"
+           "wx.rkt"
+           "kw.rkt"
+           "wxtextfield.rkt"
+           "mrcontainer.rkt"
+           "mritem.rkt"
+           "mrmenu.rkt"
+           "mrpopup.rkt")
 
   (provide text-field%
-	   combo-field%)
+           combo-field%)
 
   (define combo-flag (gensym))
 
diff --git a/collects/mred/private/mrtop.rkt b/collects/mred/private/mrtop.rkt
index b6fa45abae..662e53194c 100644
--- a/collects/mred/private/mrtop.rkt
+++ b/collects/mred/private/mrtop.rkt
@@ -1,32 +1,32 @@
 (module mrtop mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   mzlib/etc
-	   mzlib/list
-	   (prefix wx: "kernel.ss")
-	   "lock.ss"
-	   "helper.ss"
-	   "const.ss"
-	   "kw.ss"
-	   "check.ss"
-	   "wx.ss"
-	   "wxtop.ss"
-	   "wxpanel.ss"
-	   "wxitem.ss"
-	   "mrwindow.ss"
-	   "mrcontainer.ss"
-           "app.ss")
+           mzlib/class100
+           mzlib/etc
+           mzlib/list
+           (prefix wx: "kernel.rkt")
+           "lock.rkt"
+           "helper.rkt"
+           "const.rkt"
+           "kw.rkt"
+           "check.rkt"
+           "wx.rkt"
+           "wxtop.rkt"
+           "wxpanel.rkt"
+           "wxitem.rkt"
+           "mrwindow.rkt"
+           "mrcontainer.rkt"
+           "app.rkt")
 
   (provide top-level-window<%>
-	   frame%
-	   dialog%
-	   (protect root-menu-frame)
-	   get-top-level-windows
-	   get-top-level-focus-window
-	   get-top-level-edit-target-window
-	   send-message-to-window
-	   (protect check-top-level-parent/false
-		    check-frame-parent/false))
+           frame%
+           dialog%
+           (protect root-menu-frame)
+           get-top-level-windows
+           get-top-level-focus-window
+           get-top-level-edit-target-window
+           send-message-to-window
+           (protect check-top-level-parent/false
+                    check-frame-parent/false))
 
   (define top-level-window<%>
     (interface (area-container-window<%>)
diff --git a/collects/mred/private/mrwindow.rkt b/collects/mred/private/mrwindow.rkt
index 6755c6d056..317b6bdd26 100644
--- a/collects/mred/private/mrwindow.rkt
+++ b/collects/mred/private/mrwindow.rkt
@@ -1,27 +1,27 @@
 (module mrwindow mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   (prefix wx: "kernel.ss")
-	   "lock.ss"
-	   "helper.ss"
-	   "const.ss"
-	   "check.ss"
-	   "wx.ss"
-	   "kw.ss"
-	   "wxwindow.ss"
-	   "mrpopup.ss")
+           mzlib/class100
+           (prefix wx: "kernel.rkt")
+           "lock.rkt"
+           "helper.rkt"
+           "const.rkt"
+           "check.rkt"
+           "wx.rkt"
+           "kw.rkt"
+           "wxwindow.rkt"
+           "mrpopup.rkt")
 
   (provide area<%>
-	   (protect area%-keywords)
-	   area%
-	   (protect internal-subarea<%>)
-	   subarea<%>
-	   (protect subarea%-keywords
-		    make-subarea%)
-	   window<%>
-	   (protect window%-keywords)
-	   subwindow<%>
-	   (protect make-window%)
+           (protect area%-keywords)
+           area%
+           (protect internal-subarea<%>)
+           subarea<%>
+           (protect subarea%-keywords
+                    make-subarea%)
+           window<%>
+           (protect window%-keywords)
+           subwindow<%>
+           (protect make-window%)
            
            (protect set-get-outer-panel
                     set-parent))
diff --git a/collects/mred/private/path-dialog.rkt b/collects/mred/private/path-dialog.rkt
index d5250287d0..bb55947aed 100644
--- a/collects/mred/private/path-dialog.rkt
+++ b/collects/mred/private/path-dialog.rkt
@@ -1,10 +1,11 @@
 (module path-dialog mzscheme
   (require mzlib/class mzlib/list mzlib/string mzlib/file
-	   (prefix wx: "kernel.ss")
-	   (prefix wx: racket/snip)
+           (prefix wx: "kernel.rkt")
+           (prefix wx: racket/snip)
            racket/snip/private/prefs
-	   "helper.ss" "mrtop.ss" "mritem.ss" "mrpanel.ss" "mrtextfield.ss"
-           "messagebox.ss" "mrmenu.ss" (only scheme/base compose))
+           "helper.rkt" "mrtop.rkt" "mritem.rkt" "mrpanel.rkt"
+           "mrtextfield.rkt" "messagebox.rkt" "mrmenu.rkt"
+           (only scheme/base compose))
   (provide path-dialog%)
 
   (define last-visted-directory #f)
diff --git a/collects/mred/private/repl.rkt b/collects/mred/private/repl.rkt
index 173a804401..a5a9bce4c3 100644
--- a/collects/mred/private/repl.rkt
+++ b/collects/mred/private/repl.rkt
@@ -1,14 +1,14 @@
 (module repl mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   (prefix wx: "kernel.ss")
-	   (prefix wx: racket/snip)
-	   "editor.ss"
-	   "app.ss"
-	   "mrtop.ss"
-	   "mrcanvas.ss"
-	   "mrmenu.ss"
-	   "filedialog.ss")
+           mzlib/class100
+           (prefix wx: "kernel.rkt")
+           (prefix wx: racket/snip)
+           "editor.rkt"
+           "app.rkt"
+           "mrtop.rkt"
+           "mrcanvas.rkt"
+           "mrmenu.rkt"
+           "filedialog.rkt")
 
   (provide graphical-read-eval-print-loop
            textual-read-eval-print-loop)
diff --git a/collects/mred/private/snipfile.rkt b/collects/mred/private/snipfile.rkt
index 0c8a2a7d54..de328e60f8 100644
--- a/collects/mred/private/snipfile.rkt
+++ b/collects/mred/private/snipfile.rkt
@@ -1,16 +1,16 @@
 (module snipfile racket/base
   (require racket/class
            racket/port
-	   syntax/moddep
-           (prefix-in wx: "kernel.ss")
-	   (prefix-in wx: racket/snip)
-	   "check.ss"
-	   "editor.ss")
-		
-  (provide open-input-text-editor 
-	   open-input-graphical-file
-	   text-editor-load-handler
-	   open-output-text-editor )
+           syntax/moddep
+           (prefix-in wx: "kernel.rkt")
+           (prefix-in wx: racket/snip)
+           "check.rkt"
+           "editor.rkt")
+
+  (provide open-input-text-editor
+           open-input-graphical-file
+           text-editor-load-handler
+           open-output-text-editor )
 
   ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
diff --git a/collects/mred/private/wx.rkt b/collects/mred/private/wx.rkt
index 992d201f0b..f9d16f2e25 100644
--- a/collects/mred/private/wx.rkt
+++ b/collects/mred/private/wx.rkt
@@ -1,18 +1,18 @@
 (module wx mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   (prefix wx: "kernel.ss")
-	   "lock.ss"
-	   "helper.ss")
+           mzlib/class100
+           (prefix wx: "kernel.rkt")
+           "lock.rkt"
+           "helper.rkt")
 
   (provide (protect wx<%>
-		    wx/proxy<%>
-		    make-glue%
-		    wx->mred
-		    wx->proxy
-		    mred%
-		    mred->wx
-		    mred->wx-container))
+                    wx/proxy<%>
+                    make-glue%
+                    wx->mred
+                    wx->proxy
+                    mred%
+                    mred->wx
+                    mred->wx-container))
 
   ;; The windowing wx classes are not exposed directly.
   ;; Instead, we expose wrapper classes that have wx instances.
diff --git a/collects/mred/private/wx/win32/dialog.rkt b/collects/mred/private/wx/win32/dialog.rkt
index 18ed2593e0..45e1f0c11b 100644
--- a/collects/mred/private/wx/win32/dialog.rkt
+++ b/collects/mred/private/wx/win32/dialog.rkt
@@ -2,16 +2,16 @@
 (require racket/class
          (only-in racket/list last)
          ffi/unsafe
-	 "../../syntax.rkt"
-	 "../../lock.rkt"
-	 "../common/queue.rkt"
-	 "../common/freeze.rkt"
-	 "../common/dialog.rkt"
-         "utils.ss"
-         "const.ss"
-         "types.ss"
-	 "window.rkt"
-	 "frame.rkt"
+         "../../syntax.rkt"
+         "../../lock.rkt"
+         "../common/queue.rkt"
+         "../common/freeze.rkt"
+         "../common/dialog.rkt"
+         "utils.rkt"
+         "const.rkt"
+         "types.rkt"
+         "window.rkt"
+         "frame.rkt"
          "wndclass.rkt")
 
 (provide dialog%)
diff --git a/collects/mred/private/wx/win32/theme.rkt b/collects/mred/private/wx/win32/theme.rkt
index 8f0256059c..75161fe12c 100644
--- a/collects/mred/private/wx/win32/theme.rkt
+++ b/collects/mred/private/wx/win32/theme.rkt
@@ -1,9 +1,9 @@
 #lang racket/base
 (require ffi/unsafe
          ffi/unsafe/alloc
-         "utils.ss"
-         "const.ss"
-         "types.ss")
+         "utils.rkt"
+         "const.rkt"
+         "types.rkt")
 
 (provide
  (protect-out get-theme-logfont
diff --git a/collects/mred/private/wxcanvas.rkt b/collects/mred/private/wxcanvas.rkt
index 8d8591b37d..29908ba0e6 100644
--- a/collects/mred/private/wxcanvas.rkt
+++ b/collects/mred/private/wxcanvas.rkt
@@ -1,18 +1,18 @@
 (module wxcanvas mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   (prefix wx: "kernel.ss")
-	   (prefix wx: "wxme/text.ss")
-	   (prefix wx: "wxme/editor-canvas.ss")
-	   "lock.ss"
-	   "helper.ss"
-	   "wx.ss"
-	   "wxwindow.ss"
-	   "wxitem.ss")
+           mzlib/class100
+           (prefix wx: "kernel.rkt")
+           (prefix wx: "wxme/text.rkt")
+           (prefix wx: "wxme/editor-canvas.rkt")
+           "lock.rkt"
+           "helper.rkt"
+           "wx.rkt"
+           "wxwindow.rkt"
+           "wxitem.rkt")
 
   (provide (protect make-canvas-glue%
-		    wx-canvas%
-		    wx-editor-canvas%))
+                    wx-canvas%
+                    wx-editor-canvas%))
 
   (define (make-canvas-glue% default-tabable? %) ; implies make-window-glue%
     (class100 (make-window-glue% %) (mred proxy . args)
diff --git a/collects/mred/private/wxcontainer.rkt b/collects/mred/private/wxcontainer.rkt
index 29efe525bb..116d24a1bc 100644
--- a/collects/mred/private/wxcontainer.rkt
+++ b/collects/mred/private/wxcontainer.rkt
@@ -1,14 +1,14 @@
 (module wxcontainer mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   mzlib/list
-	   (prefix wx: "kernel.ss")
-	   "lock.ss"
-	   "helper.ss"
-	   "wx.ss")
+           mzlib/class100
+           mzlib/list
+           (prefix wx: "kernel.rkt")
+           "lock.rkt"
+           "helper.rkt"
+           "wx.rkt")
 
   (provide (protect make-container-glue%
-		    wx-make-container%))
+                    wx-make-container%))
 
   (define (make-container-glue% %)
     (class100 % (mr prxy . args)
diff --git a/collects/mred/private/wxitem.rkt b/collects/mred/private/wxitem.rkt
index cd081fa3e3..0220ea3dea 100644
--- a/collects/mred/private/wxitem.rkt
+++ b/collects/mred/private/wxitem.rkt
@@ -1,14 +1,14 @@
 (module wxitem racket/base
   (require mzlib/class
-	   mzlib/class100
-	   mzlib/etc
-	   (prefix-in wx: "kernel.ss")
-	   "lock.ss"
-	   "helper.ss"
-	   "const.ss"
-	   "wx.ss"
-	   "check.ss"
-	   "wxwindow.ss")
+           mzlib/class100
+           mzlib/etc
+           (prefix-in wx: "kernel.rkt")
+           "lock.rkt"
+           "helper.rkt"
+           "const.rkt"
+           "wx.rkt"
+           "check.rkt"
+           "wxwindow.rkt")
 
   (provide (protect-out make-item%
                         make-control%
diff --git a/collects/mred/private/wxlitem.rkt b/collects/mred/private/wxlitem.rkt
index 3a28522b72..5c91182e1e 100644
--- a/collects/mred/private/wxlitem.rkt
+++ b/collects/mred/private/wxlitem.rkt
@@ -1,18 +1,18 @@
 (module wxlitem mzscheme
   (require mzlib/class
-	   mzlib/class100
+           mzlib/class100
            mzlib/file
            (only racket/base remq)
            racket/snip/private/prefs
-	   (prefix wx: "kernel.ss")
-	   "lock.ss"
-	   "helper.ss"
-	   "const.ss"
-	   "wx.ss"
-	   "check.ss"
-	   "wxwindow.ss"
-	   "wxitem.ss"
-           "wxpanel.ss")
+           (prefix wx: "kernel.rkt")
+           "lock.rkt"
+           "helper.rkt"
+           "const.rkt"
+           "wx.rkt"
+           "check.rkt"
+           "wxwindow.rkt"
+           "wxitem.rkt"
+           "wxpanel.rkt")
 
   (provide (protect wx-choice%
                     wx-list-box%
diff --git a/collects/mred/private/wxme/editor-admin.rkt b/collects/mred/private/wxme/editor-admin.rkt
index d3a701fbdc..e6833af90e 100644
--- a/collects/mred/private/wxme/editor-admin.rkt
+++ b/collects/mred/private/wxme/editor-admin.rkt
@@ -1,10 +1,10 @@
 #lang scheme/base
 (require scheme/class
-         "../syntax.ss"
+         "../syntax.rkt"
          racket/snip
-         "private.ss"
+         "private.rkt"
          racket/snip/private/private
-         (only-in "cycle.ss" popup-menu%))
+         (only-in "cycle.rkt" popup-menu%))
 
 (provide editor-admin%)
 
diff --git a/collects/mred/private/wxme/editor-canvas.rkt b/collects/mred/private/wxme/editor-canvas.rkt
index bb851c129f..659c360ee1 100644
--- a/collects/mred/private/wxme/editor-canvas.rkt
+++ b/collects/mred/private/wxme/editor-canvas.rkt
@@ -1,15 +1,15 @@
 #lang scheme/base
 (require scheme/class
          scheme/file
-         "../syntax.ss"
-         "editor.ss"
-         "editor-admin.ss"
-         "private.ss"
+         "../syntax.rkt"
+         "editor.rkt"
+         "editor-admin.rkt"
+         "private.rkt"
          racket/snip/private/prefs
          racket/snip/private/private
-         (only-in "cycle.ss" popup-menu%)
-         (only-in "../helper.ss" queue-window-callback)
-         "wx.ss")
+         (only-in "cycle.rkt" popup-menu%)
+         (only-in "../helper.rkt" queue-window-callback)
+         "wx.rkt")
 
 (provide editor-canvas%)
 
diff --git a/collects/mred/private/wxme/editor-data.rkt b/collects/mred/private/wxme/editor-data.rkt
index 59ba72af66..f8905be612 100644
--- a/collects/mred/private/wxme/editor-data.rkt
+++ b/collects/mred/private/wxme/editor-data.rkt
@@ -2,19 +2,19 @@
 
 (require scheme/class
          scheme/file file/convertible
-         "../syntax.ss"
-         "private.ss"
+         "../syntax.rkt"
+         "private.rkt"
          racket/snip/private/snip-flags
          racket/snip/private/private
- 	 racket/snip/private/style
-	 racket/snip/private/load-one
-	 (only-in "cycle.ss"
+         racket/snip/private/style
+         racket/snip/private/load-one
+         (only-in "cycle.rkt"
                   editor-stream-in% editor-stream-out%
                   get-editor-data-class set-get-editor-data-class!)
          "../wx/common/event.rkt"
          racket/draw)
 
-(provide get-the-editor-data-class-list         
+(provide get-the-editor-data-class-list
          editor-data%
          editor-data-class%
          location-editor-data%
diff --git a/collects/mred/private/wxme/editor-snip-class.rkt b/collects/mred/private/wxme/editor-snip-class.rkt
index 62da1a1f31..c30feeebbd 100644
--- a/collects/mred/private/wxme/editor-snip-class.rkt
+++ b/collects/mred/private/wxme/editor-snip-class.rkt
@@ -2,12 +2,12 @@
 
 (require racket/class
          racket/file file/convertible
-         "../syntax.ss"
+         "../syntax.rkt"
          racket/snip/private/snip-flags
-         "private.ss"
+         "private.rkt"
          racket/snip/private/private
          racket/snip
-         (only-in "cycle.ss"
+         (only-in "cycle.rkt"
                   editor-stream-in% editor-stream-out%
                   extended-text% extended-pasteboard% extended-editor-snip% 
                   get-editor-data-class)
diff --git a/collects/mred/private/wxme/editor-snip.rkt b/collects/mred/private/wxme/editor-snip.rkt
index 0d715396a7..1adb76d825 100644
--- a/collects/mred/private/wxme/editor-snip.rkt
+++ b/collects/mred/private/wxme/editor-snip.rkt
@@ -1,19 +1,19 @@
 #lang scheme/base
 (require scheme/class
-         "../syntax.ss"
-         "private.ss"
+         "../syntax.rkt"
+         "private.rkt"
          racket/snip/private/private
-         "const.ss"
+         "const.rkt"
          racket/snip
          racket/snip/private/snip-flags
          "standard-snip-admin.rkt"
-         "editor.ss"
-         "editor-admin.ss"
+         "editor.rkt"
+         "editor-admin.rkt"
          "editor-snip-class.rkt"
-         "text.ss"
-         "pasteboard.ss"
-         "wx.ss"
-         (except-in "cycle.ss" 
+         "text.rkt"
+         "pasteboard.rkt"
+         "wx.rkt"
+         (except-in "cycle.rkt"
                     text%
                     pasteboard%
                     editor-snip%
@@ -32,7 +32,7 @@
     (init [(init-tmp id) v])
     (define id init-tmp)))
 
-;; see also "private.ss"
+;; see also "private.rkt"
 (define-local-member-name
   with-dc
   do-get-left-margin do-get-right-margin do-get-bottom-margin do-get-top-margin
diff --git a/collects/mred/private/wxme/editor.rkt b/collects/mred/private/wxme/editor.rkt
index 63d4a4019e..0ca48ea224 100644
--- a/collects/mred/private/wxme/editor.rkt
+++ b/collects/mred/private/wxme/editor.rkt
@@ -3,19 +3,19 @@
          (for-syntax scheme/base)
          scheme/file
          racket/port
-         "../syntax.ss"
-         "private.ss"
+         "../syntax.rkt"
+         "private.rkt"
          racket/snip
          racket/snip/private/private
-	 racket/snip/private/style
+         racket/snip/private/style
          racket/snip/private/snip-flags
          racket/snip/private/prefs
-         "editor-admin.ss"
-         "stream.ss"
-         "undo.ss"
-         "keymap.ss"
+         "editor-admin.rkt"
+         "stream.rkt"
+         "undo.rkt"
+         "keymap.rkt"
          "editor-data.rkt"
-         (only-in "cycle.ss" 
+         (only-in "cycle.rkt"
                   printer-dc%
                   text%
                   pasteboard%
@@ -23,7 +23,7 @@
                   editor-snip-editor-admin%
                   editor-get-file
                   editor-put-file)
-         "wx.ss")
+         "wx.rkt")
 
 (provide editor%
          editor<%>
@@ -763,7 +763,7 @@
   (def/public (print [bool? [interactive? #t]]
                      [bool? [fit-to-page? #t]]
                      [(symbol-in standard postscript pdf) [output-mode 'standard]]
-                     [any? [parent #f]] ; checked in ../editor.ss
+                     [any? [parent #f]] ; checked in ../editor.rkt
                      [bool? [force-page-bbox? #t]]
                      [bool? [as-eps? #f]])
     (let ([ps? (or (eq? output-mode 'postscript)
diff --git a/collects/mred/private/wxme/keymap.rkt b/collects/mred/private/wxme/keymap.rkt
index 1a7d0d52ae..b040354b9d 100644
--- a/collects/mred/private/wxme/keymap.rkt
+++ b/collects/mred/private/wxme/keymap.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 (require scheme/class
-         "../syntax.ss"
-         "wx.ss")
+         "../syntax.rkt"
+         "wx.rkt")
 
 (provide keymap%
          map-command-as-meta-key)
diff --git a/collects/mred/private/wxme/mline.rkt b/collects/mred/private/wxme/mline.rkt
index 0794bb893f..44eec89cee 100644
--- a/collects/mred/private/wxme/mline.rkt
+++ b/collects/mred/private/wxme/mline.rkt
@@ -1,10 +1,10 @@
 #lang scheme/base
 (require scheme/class
-         "../syntax.ss"
-         "const.ss"
+         "../syntax.rkt"
+         "const.rkt"
          racket/snip
          racket/snip/private/snip-flags
-         "private.ss"
+         "private.rkt"
          racket/snip/private/private)
 
 (provide create-mline
diff --git a/collects/mred/private/wxme/pasteboard.rkt b/collects/mred/private/wxme/pasteboard.rkt
index 6362c27ae7..1234d036c5 100644
--- a/collects/mred/private/wxme/pasteboard.rkt
+++ b/collects/mred/private/wxme/pasteboard.rkt
@@ -2,23 +2,23 @@
 (require scheme/class
          scheme/port
          scheme/file
-         "../syntax.ss"
-         "const.ss"
-         "private.ss"
+         "../syntax.rkt"
+         "const.rkt"
+         "private.rkt"
          racket/snip/private/private
-         "editor.ss"
+         "editor.rkt"
          "editor-data.rkt"
-         "undo.ss"
+         "undo.rkt"
          racket/snip
          racket/snip/private/snip-flags
          "standard-snip-admin.rkt"
-         "keymap.ss"
-         (only-in "cycle.ss" 
+         "keymap.rkt"
+         (only-in "cycle.rkt"
                   printer-dc%
                   set-pasteboard%!)
-         "wordbreak.ss"
-         "stream.ss"
-         "wx.ss")
+         "wordbreak.rkt"
+         "stream.rkt"
+         "wx.rkt")
 
 (provide pasteboard%
          add-pasteboard-keymap-functions)
diff --git a/collects/mred/private/wxme/standard-snip-admin.rkt b/collects/mred/private/wxme/standard-snip-admin.rkt
index b2af31611d..a55eca7256 100644
--- a/collects/mred/private/wxme/standard-snip-admin.rkt
+++ b/collects/mred/private/wxme/standard-snip-admin.rkt
@@ -1,10 +1,10 @@
 #lang scheme/base
 (require scheme/class
-         "../syntax.ss"
+         "../syntax.rkt"
          racket/snip
-         (only-in "cycle.ss" 
+         (only-in "cycle.rkt"
                   popup-menu%)
-         (prefix-in wx: "wx.ss"))
+         (prefix-in wx: "wx.rkt"))
 
 (provide standard-snip-admin%)
 
diff --git a/collects/mred/private/wxme/stream.rkt b/collects/mred/private/wxme/stream.rkt
index 246bf4241b..13cb1308a1 100644
--- a/collects/mred/private/wxme/stream.rkt
+++ b/collects/mred/private/wxme/stream.rkt
@@ -1,11 +1,11 @@
 #lang scheme/base
 (require scheme/class
-         "../syntax.ss"
-         "private.ss"
+         "../syntax.rkt"
+         "private.rkt"
          racket/snip/private/private
          racket/snip
          "editor-data.rkt"
-         (only-in "cycle.ss"
+         (only-in "cycle.rkt"
                   set-editor-stream-in%!
                   set-editor-stream-out%!))
 
diff --git a/collects/mred/private/wxme/text.rkt b/collects/mred/private/wxme/text.rkt
index bc00796113..bf1cb2c866 100644
--- a/collects/mred/private/wxme/text.rkt
+++ b/collects/mred/private/wxme/text.rkt
@@ -3,25 +3,25 @@
          scheme/port
          scheme/file
          (for-syntax scheme/base)
-         "../syntax.ss"
-         "const.ss"
-         "mline.ss"
-         "private.ss"
+         "../syntax.rkt"
+         "const.rkt"
+         "mline.rkt"
+         "private.rkt"
          racket/snip/private/private
          racket/snip/private/prefs
-         "editor.ss"
+         "editor.rkt"
          "editor-data.rkt"
-         "undo.ss"
+         "undo.rkt"
          racket/snip
          racket/snip/private/snip-flags
          "standard-snip-admin.rkt"
-         "keymap.ss"
-         (only-in "cycle.ss" 
+         "keymap.rkt"
+         (only-in "cycle.rkt"
                   printer-dc%
                   set-text%!)
-         "wordbreak.ss"
-         "stream.ss"
-         "wx.ss")
+         "wordbreak.rkt"
+         "stream.rkt"
+         "wx.rkt")
 
 (provide text%
          add-text-keymap-functions)
diff --git a/collects/mred/private/wxme/undo.rkt b/collects/mred/private/wxme/undo.rkt
index c266260af3..10d1fa85cb 100644
--- a/collects/mred/private/wxme/undo.rkt
+++ b/collects/mred/private/wxme/undo.rkt
@@ -1,6 +1,6 @@
 #lang scheme/base
 (require scheme/class
-         "private.ss"
+         "private.rkt"
          racket/snip/private/private
          racket/snip
          racket/snip/private/snip-flags)
diff --git a/collects/mred/private/wxme/wordbreak.rkt b/collects/mred/private/wxme/wordbreak.rkt
index 65cbfe5fb5..bc156d16a1 100644
--- a/collects/mred/private/wxme/wordbreak.rkt
+++ b/collects/mred/private/wxme/wordbreak.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 (require scheme/class
-         "../syntax.ss"
-         "cycle.ss")
+         "../syntax.rkt"
+         "cycle.rkt")
 
 (provide editor-wordbreak-map%
          the-editor-wordbreak-map
diff --git a/collects/mred/private/wxme/wx.rkt b/collects/mred/private/wxme/wx.rkt
index 19e4057bef..e8a845abef 100644
--- a/collects/mred/private/wxme/wx.rkt
+++ b/collects/mred/private/wxme/wx.rkt
@@ -1,5 +1,5 @@
 #lang scheme/base
-(require "../kernel.ss" racket/draw/private/font-syms)
+(require "../kernel.rkt" racket/draw/private/font-syms)
 
 (define the-clipboard (get-the-clipboard))
 (define the-x-selection-clipboard (get-the-x-selection))
diff --git a/collects/mred/private/wxmenu.rkt b/collects/mred/private/wxmenu.rkt
index d4cd5df9d7..0c43b2d1f8 100644
--- a/collects/mred/private/wxmenu.rkt
+++ b/collects/mred/private/wxmenu.rkt
@@ -1,17 +1,17 @@
 (module wxmenu mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   mzlib/list
-	   (prefix wx: "kernel.ss")
-           (prefix wx: "wxme/keymap.ss")
-	   "lock.ss"
-	   "const.ss"
-	   "helper.ss"
-	   "wx.ss")
-  
+           mzlib/class100
+           mzlib/list
+           (prefix wx: "kernel.rkt")
+           (prefix wx: "wxme/keymap.rkt")
+           "lock.rkt"
+           "const.rkt"
+           "helper.rkt"
+           "wx.rkt")
+
   (provide (protect wx-menu-item%
-		    wx-menu-bar%
-		    wx-menu%))
+                    wx-menu-bar%
+                    wx-menu%))
 
   (define wx-menu-item%
     (class100* wx:menu-item% (wx<%>) (mr mn-dat can-enable?)
diff --git a/collects/mred/private/wxpanel.rkt b/collects/mred/private/wxpanel.rkt
index 7fda7aeb20..fab0c7ba26 100644
--- a/collects/mred/private/wxpanel.rkt
+++ b/collects/mred/private/wxpanel.rkt
@@ -1,16 +1,16 @@
 (module wxpanel racket/base
   (require mzlib/class
-	   mzlib/class100
-	   mzlib/list
-	   (prefix-in wx: "kernel.ss")
-	   "lock.ss"
-	   "const.ss"
-	   "helper.ss"
-	   "check.ss"
-	   "wx.ss"
-	   "wxwindow.ss"
-	   "wxitem.ss"
-	   "wxcontainer.ss")
+           mzlib/class100
+           mzlib/list
+           (prefix-in wx: "kernel.rkt")
+           "lock.rkt"
+           "const.rkt"
+           "helper.rkt"
+           "check.rkt"
+           "wx.rkt"
+           "wxwindow.rkt"
+           "wxitem.rkt"
+           "wxcontainer.rkt")
 
   (provide (protect-out wx-panel%
                         wx-vertical-panel%
diff --git a/collects/mred/private/wxtextfield.rkt b/collects/mred/private/wxtextfield.rkt
index 82c547aa8f..3640cd9616 100644
--- a/collects/mred/private/wxtextfield.rkt
+++ b/collects/mred/private/wxtextfield.rkt
@@ -1,22 +1,22 @@
 (module wxtextfield racket/base
   (require mzlib/class
-	   mzlib/class100
-	   (prefix-in wx: "kernel.ss")
-           (prefix-in wx: "wxme/text.ss")
+           mzlib/class100
+           (prefix-in wx: "kernel.rkt")
+           (prefix-in wx: "wxme/text.rkt")
            (prefix-in wx: racket/snip)
-           (prefix-in wx: "wxme/editor-canvas.ss")
-	   "lock.ss"
-	   "const.ss"
-	   "check.ss"
-	   "helper.ss"
-	   "gdi.ss"
-	   "wx.ss"
-	   "wxwindow.ss"
-	   "wxitem.ss"
-	   "wxcanvas.ss"
-	   "wxpanel.ss"
-	   "editor.ss"
-	   "mrpopup.ss")
+           (prefix-in wx: "wxme/editor-canvas.rkt")
+           "lock.rkt"
+           "const.rkt"
+           "check.rkt"
+           "helper.rkt"
+           "gdi.rkt"
+           "wx.rkt"
+           "wxwindow.rkt"
+           "wxitem.rkt"
+           "wxcanvas.rkt"
+           "wxpanel.rkt"
+           "editor.rkt"
+           "mrpopup.rkt")
 
   (provide (protect-out wx-text-field%))
 
diff --git a/collects/mred/private/wxtop.rkt b/collects/mred/private/wxtop.rkt
index 3dba64fd54..8d54cf68f6 100644
--- a/collects/mred/private/wxtop.rkt
+++ b/collects/mred/private/wxtop.rkt
@@ -1,19 +1,19 @@
 (module wxtop mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   mzlib/etc
-	   mzlib/list
-	   (prefix wx: "kernel.ss")
-           (prefix wx: "wxme/editor-canvas.ss")
-           (prefix wx: "wxme/editor-snip.ss")
-	   "lock.ss"
-	   "helper.ss"
-	   "const.ss"
-	   "kw.ss"
-	   "check.ss"
-	   "wx.ss"
-	   "wxwindow.ss"
-	   "wxcontainer.ss")
+           mzlib/class100
+           mzlib/etc
+           mzlib/list
+           (prefix wx: "kernel.rkt")
+           (prefix wx: "wxme/editor-canvas.rkt")
+           (prefix wx: "wxme/editor-snip.rkt")
+           "lock.rkt"
+           "helper.rkt"
+           "const.rkt"
+           "kw.rkt"
+           "check.rkt"
+           "wx.rkt"
+           "wxwindow.rkt"
+           "wxcontainer.rkt")
 
   (provide (protect active-main-frame
                     set-root-menu-wx-frame!)
diff --git a/collects/mred/private/wxwindow.rkt b/collects/mred/private/wxwindow.rkt
index 7d82d2731d..b9e0862322 100644
--- a/collects/mred/private/wxwindow.rkt
+++ b/collects/mred/private/wxwindow.rkt
@@ -1,14 +1,14 @@
 (module wxwindow mzscheme
   (require mzlib/class
-	   mzlib/class100
-	   (prefix wx: "kernel.ss")
+           mzlib/class100
+           (prefix wx: "kernel.rkt")
            "te.rkt"
-	   "lock.ss"
-	   "helper.ss"
-	   "wx.ss")
+           "lock.rkt"
+           "helper.rkt"
+           "wx.rkt")
 
   (provide (protect wx-make-window%
-		    make-window-glue%))
+                    make-window-glue%))
 
   (define wx-make-window%
     (lambda (% top?)
diff --git a/collects/mrlib/aligned-pasteboard.rkt b/collects/mrlib/aligned-pasteboard.rkt
index a6c1e084fd..c88ff632dd 100644
--- a/collects/mrlib/aligned-pasteboard.rkt
+++ b/collects/mrlib/aligned-pasteboard.rkt
@@ -1,9 +1,9 @@
 (module aligned-pasteboard mzscheme
   (require
-    "private/aligned-pasteboard/aligned-pasteboard.ss"
-    "private/aligned-pasteboard/aligned-editor-container.ss"
-    "private/aligned-pasteboard/interface.ss"
-    "private/aligned-pasteboard/stretchable-editor-snip.ss")
+    "private/aligned-pasteboard/aligned-pasteboard.rkt"
+    "private/aligned-pasteboard/aligned-editor-container.rkt"
+    "private/aligned-pasteboard/interface.rkt"
+    "private/aligned-pasteboard/stretchable-editor-snip.rkt")
   (provide
     vertical-pasteboard%
     horizontal-pasteboard%
diff --git a/collects/mrlib/hierlist.rkt b/collects/mrlib/hierlist.rkt
index c02b527d4a..1c3baf6073 100644
--- a/collects/mrlib/hierlist.rkt
+++ b/collects/mrlib/hierlist.rkt
@@ -2,8 +2,8 @@
 
 (require mzlib/unit
          scheme/gui/base
-         "hierlist/hierlist-sig.ss"
-         "hierlist/hierlist-unit.ss")
+         "hierlist/hierlist-sig.rkt"
+         "hierlist/hierlist-unit.rkt")
 
 (define-values/invoke-unit/infer hierlist@)
 
diff --git a/collects/mrlib/hierlist/hierlist-unit.rkt b/collects/mrlib/hierlist/hierlist-unit.rkt
index 9c51f6d6ed..a0afba260a 100644
--- a/collects/mrlib/hierlist/hierlist-unit.rkt
+++ b/collects/mrlib/hierlist/hierlist-unit.rkt
@@ -1,14 +1,13 @@
-
 (module hierlist-unit mzscheme
   (require (all-except mzlib/unit rename)
-	   mzlib/class
-	   mzlib/class100
-	   mred/mred-sig
-	   mrlib/include-bitmap
-	   "hierlist-sig.ss")
+           mzlib/class
+           mzlib/class100
+           mred/mred-sig
+           mrlib/include-bitmap
+           "hierlist-sig.rkt")
 
   (require (rename mzlib/list sort* sort)
-	   mzlib/etc)
+           mzlib/etc)
 
   (define turn-up (include-bitmap "../../icons/turn-up.png" 'png/mask))
   (define turn-down (include-bitmap "../../icons/turn-down.png" 'png/mask))
diff --git a/collects/mrlib/image-core.rkt b/collects/mrlib/image-core.rkt
index f4c23f299c..c90e337685 100644
--- a/collects/mrlib/image-core.rkt
+++ b/collects/mrlib/image-core.rkt
@@ -30,15 +30,15 @@ has been moved out).
 (require racket/class
          racket/draw
          (for-syntax racket/base)
-         file/convertible         
+         file/convertible
          racket/math
          racket/contract
-         "private/image-core-bitmap.ss" 
-         "image-core-wxme.ss"
+         "private/image-core-bitmap.rkt"
+         "image-core-wxme.rkt"
          "private/image-core-snipclass.rkt"
          "private/regmk.rkt"
          racket/snip
-         (prefix-in cis: "cache-image-snip.ss"))
+         (prefix-in cis: "cache-image-snip.rkt"))
 
 
 
diff --git a/collects/mrlib/interactive-value-port.rkt b/collects/mrlib/interactive-value-port.rkt
index 1703dc07f2..566faf280c 100644
--- a/collects/mrlib/interactive-value-port.rkt
+++ b/collects/mrlib/interactive-value-port.rkt
@@ -1,9 +1,8 @@
-
 (module interactive-value-port mzscheme
   (require mzlib/pretty
            mred
            mzlib/class
-           "syntax-browser.ss")
+           "syntax-browser.rkt")
   (provide set-interactive-display-handler
            set-interactive-write-handler
            set-interactive-print-handler)
diff --git a/collects/mrlib/matrix-snip.rkt b/collects/mrlib/matrix-snip.rkt
index 1a82069945..8949e23afe 100644
--- a/collects/mrlib/matrix-snip.rkt
+++ b/collects/mrlib/matrix-snip.rkt
@@ -29,7 +29,7 @@
 (define (v-m VM) (send VM get-M))
 (define (v? VM) (is-a? VM visible-matrix%))
 
-;; representing a matrix that renders itself as an image, as in image.ss
+;; representing a matrix that renders itself as an image, as in "image.rkt"
 (define visible-matrix%
   (class cache-image-snip%
     (inherit set-snipclass get-argb)
diff --git a/collects/mrlib/private/aligned-pasteboard/aligned-editor-container.rkt b/collects/mrlib/private/aligned-pasteboard/aligned-editor-container.rkt
index f043cef906..ceabd22d3b 100644
--- a/collects/mrlib/private/aligned-pasteboard/aligned-editor-container.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/aligned-editor-container.rkt
@@ -5,14 +5,14 @@
    mred
    mzlib/etc
    mzlib/list
-   "snip-lib.ss"
-   "interface.ss"
-   "constants.ss")
-  
+   "snip-lib.rkt"
+   "interface.rkt"
+   "constants.rkt")
+
   (provide
    aligned-editor-canvas%
    aligned-editor-snip%)
-  
+
   ;; a canvas that can contain an aligned-pasteboard<%>
   ;; STATUS: When both min-width and min-height change the size of the canvas
   ;;         I might be getting two on-size method invocations inside
diff --git a/collects/mrlib/private/aligned-pasteboard/aligned-pasteboard.rkt b/collects/mrlib/private/aligned-pasteboard/aligned-pasteboard.rkt
index 4f3fb59548..b437f0cc8e 100644
--- a/collects/mrlib/private/aligned-pasteboard/aligned-pasteboard.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/aligned-pasteboard.rkt
@@ -2,8 +2,8 @@
   
   (require
    mrlib/click-forwarding-editor
-   "geometry-managed-pasteboard.ss"
-   "locked-pasteboard.ss")
+   "geometry-managed-pasteboard.rkt"
+   "locked-pasteboard.rkt")
   
   (provide
    vertical-pasteboard%
diff --git a/collects/mrlib/private/aligned-pasteboard/geometry-managed-pasteboard.rkt b/collects/mrlib/private/aligned-pasteboard/geometry-managed-pasteboard.rkt
index 2773b2e794..9277541de8 100644
--- a/collects/mrlib/private/aligned-pasteboard/geometry-managed-pasteboard.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/geometry-managed-pasteboard.rkt
@@ -7,11 +7,11 @@
    mzlib/etc
    mzlib/match
    mred
-   "aligned-editor-container.ss"
-   "interface.ss"
-   "alignment.ss"
-   "snip-lib.ss"
-   "pasteboard-lib.ss")
+   "aligned-editor-container.rkt"
+   "interface.rkt"
+   "alignment.rkt"
+   "snip-lib.rkt"
+   "pasteboard-lib.rkt")
   
   (provide/contract (make-aligned-pasteboard ((symbols 'vertical 'horizontal) . -> . class?)))
   
diff --git a/collects/mrlib/private/aligned-pasteboard/pasteboard-lib.rkt b/collects/mrlib/private/aligned-pasteboard/pasteboard-lib.rkt
index 9d6a004253..a585c70d3d 100644
--- a/collects/mrlib/private/aligned-pasteboard/pasteboard-lib.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/pasteboard-lib.rkt
@@ -5,8 +5,8 @@
    mred
    mzlib/contract
    mzlib/etc
-   "interface.ss"
-   "snip-lib.ss")
+   "interface.rkt"
+   "snip-lib.rkt")
   
   (provide/contract
    (pasteboard-root ((is-a?/c aligned-pasteboard<%>) . -> . (is-a?/c aligned-pasteboard<%>)))
diff --git a/collects/mrlib/private/aligned-pasteboard/snip-lib.rkt b/collects/mrlib/private/aligned-pasteboard/snip-lib.rkt
index 2a5fd19c9d..b371e51b35 100644
--- a/collects/mrlib/private/aligned-pasteboard/snip-lib.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/snip-lib.rkt
@@ -6,7 +6,7 @@
    mred
    mzlib/list
    mzlib/contract
-   "interface.ss")
+   "interface.rkt")
   
   ;; a snip
   (define snip? (is-a?/c snip%))
diff --git a/collects/mrlib/private/aligned-pasteboard/stretchable-editor-snip.rkt b/collects/mrlib/private/aligned-pasteboard/stretchable-editor-snip.rkt
index bed22c43cb..597d4fffdf 100644
--- a/collects/mrlib/private/aligned-pasteboard/stretchable-editor-snip.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/stretchable-editor-snip.rkt
@@ -8,8 +8,8 @@
    mzlib/class
    mred
    mzlib/etc
-   "snip-lib.ss"
-   "interface.ss")
+   "snip-lib.rkt"
+   "interface.rkt")
   
   (define (stretchable-editor-snip-mixin super%)
     (class* super% (stretchable-snip<%>)
diff --git a/collects/mrlib/private/aligned-pasteboard/tests/example-min.rkt b/collects/mrlib/private/aligned-pasteboard/tests/example-min.rkt
index 9255c3603d..712076b49a 100644
--- a/collects/mrlib/private/aligned-pasteboard/tests/example-min.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/tests/example-min.rkt
@@ -2,8 +2,8 @@
  mzlib/class
  mred
  mzlib/etc
- "../aligned-pasteboard.ss"
- "../aligned-editor-container.ss")
+ "../aligned-pasteboard.rkt"
+ "../aligned-editor-container.rkt")
 
 (define f (new frame% (label "") (width 400) (height 400)))
 (define e (new horizontal-pasteboard%))
diff --git a/collects/mrlib/private/aligned-pasteboard/tests/example.rkt b/collects/mrlib/private/aligned-pasteboard/tests/example.rkt
index 1e3a0e7148..40240169cd 100644
--- a/collects/mrlib/private/aligned-pasteboard/tests/example.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/tests/example.rkt
@@ -2,8 +2,8 @@
  mzlib/class
  mred
  mzlib/etc
- "../aligned-pasteboard.ss"
- "../aligned-editor-container.ss")
+ "../aligned-pasteboard.rkt"
+ "../aligned-editor-container.rkt")
 
 ;                                                          
 ;                                                          
diff --git a/collects/mrlib/private/aligned-pasteboard/tests/minimal.rkt b/collects/mrlib/private/aligned-pasteboard/tests/minimal.rkt
index 9a5ac83aed..eac247ec31 100644
--- a/collects/mrlib/private/aligned-pasteboard/tests/minimal.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/tests/minimal.rkt
@@ -1,6 +1,6 @@
 (require
- "../aligned-editor-container.ss"
- "../aligned-pasteboard.ss")
+ "../aligned-editor-container.rkt"
+ "../aligned-pasteboard.rkt")
 
 (define f (new frame% (label "test") (width 200) (height 200)))
 (define e (new vertical-pasteboard%))
diff --git a/collects/mrlib/private/aligned-pasteboard/tests/more-tests-margin-aligned.rkt b/collects/mrlib/private/aligned-pasteboard/tests/more-tests-margin-aligned.rkt
index 07d54cf95d..4d037c12de 100644
--- a/collects/mrlib/private/aligned-pasteboard/tests/more-tests-margin-aligned.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/tests/more-tests-margin-aligned.rkt
@@ -1,6 +1,6 @@
 (require
- "../aligned-editor-container.ss"
- "../aligned-pasteboard.ss")
+ "../aligned-editor-container.rkt"
+ "../aligned-pasteboard.rkt")
 
 (define pb (new horizontal-pasteboard%))
 (send* pb
@@ -15,7 +15,7 @@
 
 ;;;;;;;;;;
 ;; exploration
-(require "../snip-lib.ss")
+(require "../snip-lib.rkt")
 (define (margin snip)
   (let ([left (box 0)]
         [top (box 0)]
diff --git a/collects/mrlib/private/aligned-pasteboard/tests/more-tests-margin.rkt b/collects/mrlib/private/aligned-pasteboard/tests/more-tests-margin.rkt
index 6e094568a2..d4e0de58dd 100644
--- a/collects/mrlib/private/aligned-pasteboard/tests/more-tests-margin.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/tests/more-tests-margin.rkt
@@ -1,6 +1,6 @@
 (require
- "../aligned-editor-container.ss"
- "../aligned-pasteboard.ss")
+ "../aligned-editor-container.rkt"
+ "../aligned-pasteboard.rkt")
 
 (define pb (new horizontal-pasteboard%))
 (send* pb
@@ -15,7 +15,7 @@
 
 ;;;;;;;;;;
 ;; exploration
-(require "../snip-lib.ss")
+(require "../snip-lib.rkt")
 (define (margin snip)
   (let ([left (box 0)]
         [top (box 0)]
diff --git a/collects/mrlib/private/aligned-pasteboard/tests/more-tests-min-stretchable.rkt b/collects/mrlib/private/aligned-pasteboard/tests/more-tests-min-stretchable.rkt
index 0e61f76ad7..65b97c7dd4 100644
--- a/collects/mrlib/private/aligned-pasteboard/tests/more-tests-min-stretchable.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/tests/more-tests-min-stretchable.rkt
@@ -1,6 +1,6 @@
 (require
- "../aligned-editor-container.ss"
- "../aligned-pasteboard.ss")
+ "../aligned-editor-container.rkt"
+ "../aligned-pasteboard.rkt")
 
 (define editor (new vertical-pasteboard%))
 (define pb (new horizontal-pasteboard%))
@@ -18,7 +18,7 @@
 
 ;;;;;;;;;;
 ;; exploration
-(require "../snip-lib.ss")
+(require "../snip-lib.rkt")
 (define t-e (send t get-editor))
 (send t-e get-aligned-min-width)
 (send t get-aligned-min-width)
diff --git a/collects/mrlib/private/aligned-pasteboard/tests/more-tests-min.rkt b/collects/mrlib/private/aligned-pasteboard/tests/more-tests-min.rkt
index a0499e2a3a..9f0bbaf019 100644
--- a/collects/mrlib/private/aligned-pasteboard/tests/more-tests-min.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/tests/more-tests-min.rkt
@@ -1,6 +1,6 @@
 (require
- "../aligned-editor-container.ss"
- "../aligned-pasteboard.ss")
+ "../aligned-editor-container.rkt"
+ "../aligned-pasteboard.rkt")
 
 (define editor (new vertical-pasteboard%))
 (define pb (new horizontal-pasteboard%))
@@ -20,7 +20,7 @@
 
 ;;;;;;;;;;
 ;; exploration
-(require "../snip-lib.ss")
+(require "../snip-lib.rkt")
 (define t-e (send t get-editor))
 (send t-e get-aligned-min-width)
 (send t get-aligned-min-width)
diff --git a/collects/mrlib/private/aligned-pasteboard/tests/more-tests-text.rkt b/collects/mrlib/private/aligned-pasteboard/tests/more-tests-text.rkt
index 0d6ff68702..3f6cea5b64 100644
--- a/collects/mrlib/private/aligned-pasteboard/tests/more-tests-text.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/tests/more-tests-text.rkt
@@ -1,8 +1,8 @@
 ;; Note this test case fails when the snip 'y' is stretchable. There is lots of extra space. Finding out
 ;; why will probably fix the test case's extra space.
 (require
- "../aligned-editor-container.ss"
- "../aligned-pasteboard.ss")
+ "../aligned-editor-container.rkt"
+ "../aligned-pasteboard.rkt")
 
 (define editor (new vertical-pasteboard%))
 (define pb (new horizontal-pasteboard%))
@@ -29,7 +29,7 @@
 ;; exploration
 (eq-hash-code y)
 (eq-hash-code t)
-(require "../snip-lib.ss")
+(require "../snip-lib.rkt")
 (define (margin snip)
   (let ([left (box 0)]
         [top (box 0)]
diff --git a/collects/mrlib/private/aligned-pasteboard/tests/more-tests.rkt b/collects/mrlib/private/aligned-pasteboard/tests/more-tests.rkt
index f00928a031..2514fae1f4 100644
--- a/collects/mrlib/private/aligned-pasteboard/tests/more-tests.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/tests/more-tests.rkt
@@ -4,8 +4,8 @@
  mzlib/class
  mred
  mzlib/etc
- "../aligned-editor-container.ss"
- "../aligned-pasteboard.ss")
+ "../aligned-editor-container.rkt"
+ "../aligned-pasteboard.rkt")
 
 ;; a text-case snip
 (define test-case-box%
diff --git a/collects/mrlib/private/aligned-pasteboard/tests/stretchable-editor-snip-test-min.rkt b/collects/mrlib/private/aligned-pasteboard/tests/stretchable-editor-snip-test-min.rkt
index 6632278971..fa2b1a46a9 100644
--- a/collects/mrlib/private/aligned-pasteboard/tests/stretchable-editor-snip-test-min.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/tests/stretchable-editor-snip-test-min.rkt
@@ -1,8 +1,8 @@
 (require
- "../aligned-pasteboard.ss"
- "../aligned-editor-container.ss"
- "../stretchable-editor-snip.ss"
- "../snip-lib.ss")
+ "../aligned-pasteboard.rkt"
+ "../aligned-editor-container.rkt"
+ "../stretchable-editor-snip.rkt"
+ "../snip-lib.rkt")
 
 (define f (new frame% (label "") (width 500) (height 500)))
 (define e (new vertical-pasteboard%))
diff --git a/collects/mrlib/private/aligned-pasteboard/tests/stretchable-editor-snip-test.rkt b/collects/mrlib/private/aligned-pasteboard/tests/stretchable-editor-snip-test.rkt
index cf626ec2da..4489c1d0a7 100644
--- a/collects/mrlib/private/aligned-pasteboard/tests/stretchable-editor-snip-test.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/tests/stretchable-editor-snip-test.rkt
@@ -1,8 +1,8 @@
 (require
- "../aligned-pasteboard.ss"
- "../aligned-editor-container.ss"
- "../stretchable-editor-snip.ss"
- "../snip-lib.ss")
+ "../aligned-pasteboard.rkt"
+ "../aligned-editor-container.rkt"
+ "../stretchable-editor-snip.rkt"
+ "../snip-lib.rkt")
 
 (define f (new frame% (label "") (width 500) (height 500)))
 (define e (new vertical-pasteboard%))
diff --git a/collects/mrlib/private/aligned-pasteboard/tests/test-locked-pasteboard.rkt b/collects/mrlib/private/aligned-pasteboard/tests/test-locked-pasteboard.rkt
index 3ee53399a7..5e37448fcf 100644
--- a/collects/mrlib/private/aligned-pasteboard/tests/test-locked-pasteboard.rkt
+++ b/collects/mrlib/private/aligned-pasteboard/tests/test-locked-pasteboard.rkt
@@ -1,5 +1,5 @@
 (require
- "../locked-pasteboard.ss"
+ "../locked-pasteboard.rkt"
  mrlib/click-forwarding-editor)
 
 (define f (new frame% (width 400) (height 500) (label "test")))
diff --git a/collects/mrlib/scribblings/aligned-pasteboard/common.rkt b/collects/mrlib/scribblings/aligned-pasteboard/common.rkt
index 9f62762a2a..6ab5821430 100644
--- a/collects/mrlib/scribblings/aligned-pasteboard/common.rkt
+++ b/collects/mrlib/scribblings/aligned-pasteboard/common.rkt
@@ -1,8 +1,7 @@
 #lang scheme/base
 
-(require "../common.ss"
+(require "../common.rkt"
          (for-label mrlib/aligned-pasteboard))
 
-(provide (all-from-out "../common.ss")
+(provide (all-from-out "../common.rkt")
          (for-label (all-from-out mrlib/aligned-pasteboard)))
-
diff --git a/collects/mrlib/scribblings/graph/common.rkt b/collects/mrlib/scribblings/graph/common.rkt
index 94dac0ffc1..5a5fdd64c9 100644
--- a/collects/mrlib/scribblings/graph/common.rkt
+++ b/collects/mrlib/scribblings/graph/common.rkt
@@ -1,8 +1,7 @@
 #lang scheme/base
 
-(require "../common.ss"
+(require "../common.rkt"
          (for-label mrlib/graph))
 
-(provide (all-from-out "../common.ss")
+(provide (all-from-out "../common.rkt")
          (for-label (all-from-out mrlib/graph)))
-
diff --git a/collects/mrlib/syntax-browser.rkt b/collects/mrlib/syntax-browser.rkt
index dc01c9e02f..937a331fb6 100644
--- a/collects/mrlib/syntax-browser.rkt
+++ b/collects/mrlib/syntax-browser.rkt
@@ -13,7 +13,7 @@ needed to really make this work:
            mred
            mzlib/match
            mzlib/string
-	   "include-bitmap.ss")
+           "include-bitmap.rkt")
 
   (define orig-output-port (current-output-port))
   (define (oprintf . args) (apply fprintf orig-output-port args))
diff --git a/collects/mysterx/main.rkt b/collects/mysterx/main.rkt
index b0bbe9def5..23186775b4 100644
--- a/collects/mysterx/main.rkt
+++ b/collects/mysterx/main.rkt
@@ -1,4 +1,4 @@
 #lang scheme/base
 
-(require "mysterx.ss")
-(provide (all-from-out "mysterx.ss"))
+(require "mysterx.rkt")
+(provide (all-from-out "mysterx.rkt"))
diff --git a/collects/mysterx/mxdemo.rkt b/collects/mysterx/mxdemo.rkt
index cf07b3ad73..87194753c1 100644
--- a/collects/mysterx/mxdemo.rkt
+++ b/collects/mysterx/mxdemo.rkt
@@ -1,4 +1,4 @@
-;;; mxdemo.ss -- demo program for MysterX
+;;; mxdemo.rkt -- demo program for MysterX
 
 ;;; Requires the MSCal Calendar control.
 ;;; The calendar control is normally installed with
diff --git a/collects/mysterx/mysterx.rkt b/collects/mysterx/mysterx.rkt
index d3b703fe01..7ec6e629b6 100644
--- a/collects/mysterx/mysterx.rkt
+++ b/collects/mysterx/mysterx.rkt
@@ -1,14 +1,14 @@
-;; mysterx.ss
+;; mysterx.rkt
 
 (module mysterx mzscheme
 
   ; private mysterx modules
 
-  (require (prefix mxprims: "private/mxmain.ss"))
-  (require (prefix style: "private/style.ss"))
-  (require "private/filter.ss")
-  (require "private/properties.ss")
-  (require "private/util.ss")
+  (require (prefix mxprims: "private/mxmain.rkt")
+           (prefix style: "private/style.rkt")
+           "private/filter.rkt"
+           "private/properties.rkt"
+           "private/util.rkt")
 
   ; mzlib
 
diff --git a/collects/mysterx/private/filter.rkt b/collects/mysterx/private/filter.rkt
index 6adb56c8b1..d70db0cbf6 100644
--- a/collects/mysterx/private/filter.rkt
+++ b/collects/mysterx/private/filter.rkt
@@ -1,9 +1,9 @@
-;;; filter.ss
+;;; filter.rkt
 
 (module filter mzscheme
-  (require mzlib/string)
-  (require "properties.ss")
-  (require "util.ss")
+  (require mzlib/string
+           "properties.rkt"
+           "util.rkt")
 
   (provide
    string->filter
diff --git a/collects/mysterx/private/mxmain.rkt b/collects/mysterx/private/mxmain.rkt
index 155cb3c006..382a7af6a7 100644
--- a/collects/mysterx/private/mxmain.rkt
+++ b/collects/mysterx/private/mxmain.rkt
@@ -288,7 +288,7 @@
    com-omit
    %%initialize-dotnet-runtime)
 
-  (error "mxmain.ss: you seem to be missing mxmain.dll; you need to build MysterX in plt\\src\\mysterx\\")
+  (error "mxmain.rkt: you seem to be missing mxmain.dll; you need to build MysterX in plt\\src\\mysterx\\")
 
   (define mx-version #f)
   (define block-while-browsers #f)
diff --git a/collects/mysterx/private/prims.rkt b/collects/mysterx/private/prims.rkt
index b2b4fdfba1..2b63381daf 100644
--- a/collects/mysterx/private/prims.rkt
+++ b/collects/mysterx/private/prims.rkt
@@ -1,7 +1,7 @@
-;; prims.ss
+;; prims.rkt
 
 (module prims mzscheme
-  (require "mxmain.ss")
+  (require "mxmain.rkt")
 
   (provide 
    mx-version
diff --git a/collects/mysterx/private/properties.rkt b/collects/mysterx/private/properties.rkt
index d67e931518..103c85f5e2 100644
--- a/collects/mysterx/private/properties.rkt
+++ b/collects/mysterx/private/properties.rkt
@@ -1,4 +1,4 @@
-;; properties.ss
+;; properties.rkt
 
 (module properties mzscheme
   (require mzlib/list)	
diff --git a/collects/mysterx/private/style.rkt b/collects/mysterx/private/style.rkt
index d4a3e9bb95..92912cd455 100644
--- a/collects/mysterx/private/style.rkt
+++ b/collects/mysterx/private/style.rkt
@@ -1,9 +1,9 @@
-;;; style.ss 
+;;; style.rkt
 
 (module style mzscheme
   (require mzlib/string)
-  (require "util.ss")
-  (require "properties.ss")
+  (require "util.rkt")
+  (require "properties.rkt")
 
   (provide
    make-css-percentage
diff --git a/collects/mysterx/private/util.rkt b/collects/mysterx/private/util.rkt
index f7551c8476..e838d767df 100644
--- a/collects/mysterx/private/util.rkt
+++ b/collects/mysterx/private/util.rkt
@@ -1,4 +1,4 @@
-;;; util.ss -- utility procedures for MysterX
+;;; util.rkt -- utility procedures for MysterX
 #lang scheme/base
 
 (require scheme/string)
diff --git a/collects/mzlib/class-traced.rkt b/collects/mzlib/class-traced.rkt
index cb26623a2f..3105f658e4 100644
--- a/collects/mzlib/class-traced.rkt
+++ b/collects/mzlib/class-traced.rkt
@@ -1,7 +1,7 @@
 (module class-traced mzscheme
   
-  ;; All of the implementation is actually in private/class-internal.ss,
-  ;;  which provides extra (private) functionality to contract.ss.
+  ;; All of the implementation is actually in private/class-internal.rkt,
+  ;;  which provides extra (private) functionality to contract.rkt.
   (require racket/private/class-internal)
   
   (provide (rename class-traced class)
diff --git a/collects/mzlib/pregexp.rkt b/collects/mzlib/pregexp.rkt
index fe41060bf3..5d2c4940ee 100644
--- a/collects/mzlib/pregexp.rkt
+++ b/collects/mzlib/pregexp.rkt
@@ -1,4 +1,4 @@
-;pregexp.ss
+;; pregexp.rkt
 ;; Originally:
 ;;   ;Portable regular expressions for Scheme
 ;;   ;Dorai Sitaram
diff --git a/collects/mzlib/private/port.rkt b/collects/mzlib/private/port.rkt
index 33cde9a312..d7f4892bfb 100644
--- a/collects/mzlib/private/port.rkt
+++ b/collects/mzlib/private/port.rkt
@@ -1,6 +1,5 @@
-
-;; A few simple port functions are needed in pretty.ss, which is
-;;  used by contract.ss, which is used by port.ss --- so we
+;; A few simple port functions are needed in pretty.rkt, which is
+;;  used by contract.rkt, which is used by port.rkt --- so we
 ;;  break the cycle with this module.
 
 (module port racket/base
diff --git a/collects/mzlib/private/sigmatch.rkt b/collects/mzlib/private/sigmatch.rkt
index 84d0fc4411..2122e79bb4 100644
--- a/collects/mzlib/private/sigmatch.rkt
+++ b/collects/mzlib/private/sigmatch.rkt
@@ -1,7 +1,6 @@
-
 (module sigmatch mzscheme
 
-  (require "../unit200.ss")
+  (require "../unit200.rkt")
 
   (define (hash-sig src-sig table)
     (and (pair? src-sig)
diff --git a/collects/mzlib/shared.rkt b/collects/mzlib/shared.rkt
index bb6e262e8e..05829979ca 100644
--- a/collects/mzlib/shared.rkt
+++ b/collects/mzlib/shared.rkt
@@ -16,5 +16,5 @@
   (lambda (stx)
     (define make-check-cdr #f)
     ;; Include the implementation.
-    ;; See private/shared-body.ss.
+    ;; See private/shared-body.rkt.
     (include "private/shared-body.rkt")))
diff --git a/collects/mzscheme/examples/curses-demo.rkt b/collects/mzscheme/examples/curses-demo.rkt
index e016682802..671108abcf 100644
--- a/collects/mzscheme/examples/curses-demo.rkt
+++ b/collects/mzscheme/examples/curses-demo.rkt
@@ -1,5 +1,5 @@
 ; Uses the curses.so extension. Run with
-;    mzscheme -r curses-demo.ss
+;    racket -r curses-demo.rkt
 
 ; To get append-extension-suffix, which adds .so or .dll as
 ; approrpiate for the current platform:
diff --git a/collects/mzscheme/examples/msgbox.rkt b/collects/mzscheme/examples/msgbox.rkt
index 18caceac61..84a88cb55c 100644
--- a/collects/mzscheme/examples/msgbox.rkt
+++ b/collects/mzscheme/examples/msgbox.rkt
@@ -1,5 +1,5 @@
 ;; Build with
-;;   mzc ++ldf user32.lib msgbox.ss
+;;   mzc ++ldf user32.lib msgbox.rkt
 ;; so that MessageBox() is linked in.
 
 (module msgbox mzscheme
diff --git a/collects/openssl/main.rkt b/collects/openssl/main.rkt
index ddf2f3c8d5..50234b1a8b 100644
--- a/collects/openssl/main.rkt
+++ b/collects/openssl/main.rkt
@@ -1,4 +1,4 @@
 #lang scheme/base
 
-(require "mzssl.ss")
-(provide (all-from-out "mzssl.ss"))
+(require "mzssl.rkt")
+(provide (all-from-out "mzssl.rkt"))
diff --git a/collects/openssl/openssl.rkt b/collects/openssl/openssl.rkt
index a65c3b3832..0fb1348221 100644
--- a/collects/openssl/openssl.rkt
+++ b/collects/openssl/openssl.rkt
@@ -1,4 +1,4 @@
 (module openssl mzscheme
-  (require "mzssl.ss")
+  (require "mzssl.rkt")
 
   (provide ssl-connect))
diff --git a/collects/parser-tools/examples/read.rkt b/collects/parser-tools/examples/read.rkt
index a07d537e53..842eff7cd1 100644
--- a/collects/parser-tools/examples/read.rkt
+++ b/collects/parser-tools/examples/read.rkt
@@ -59,7 +59,7 @@
    [comment (:: #\; (:* (:~ #\newline)) #\newline)]
    
    
-   ;; See ${PLTHOME}/collects/syntax-color/scheme-lexer.ss for an example of
+   ;; See ${PLTHOME}/collects/syntax-color/scheme-lexer.rkt for an example of
    ;; using regexp macros to avoid the cut and paste.
    ;   [numR (:: prefixR complexR)]
    ;   [complexR (:or realR
diff --git a/collects/parser-tools/lex.rkt b/collects/parser-tools/lex.rkt
index f495f10c09..e71f634bab 100644
--- a/collects/parser-tools/lex.rkt
+++ b/collects/parser-tools/lex.rkt
@@ -2,19 +2,19 @@
 
   ;; Provides the syntax used to create lexers and the functions needed to
   ;; create and use the buffer that the lexer reads from.  See docs.
-	
+
   (require-for-syntax mzlib/list
                       syntax/stx
                       syntax/define
                       syntax/boundmap
-                      "private-lex/util.ss"
-                      "private-lex/actions.ss"
-                      "private-lex/front.ss"
-                      "private-lex/unicode-chars.ss")
+                      "private-lex/util.rkt"
+                      "private-lex/actions.rkt"
+                      "private-lex/front.rkt"
+                      "private-lex/unicode-chars.rkt")
 
   (require mzlib/stxparam
            syntax/readerr
-           "private-lex/token.ss")
+           "private-lex/token.rkt")
 
   (provide lexer lexer-src-pos define-lex-abbrev define-lex-abbrevs define-lex-trans
            
diff --git a/collects/parser-tools/private-lex/deriv.rkt b/collects/parser-tools/private-lex/deriv.rkt
index e398d4fdc4..28919a3261 100644
--- a/collects/parser-tools/private-lex/deriv.rkt
+++ b/collects/parser-tools/private-lex/deriv.rkt
@@ -2,8 +2,8 @@
   
   (require mzlib/list
            (prefix is: mzlib/integer-set)
-           "re.ss"
-           "util.ss")
+           "re.rkt"
+           "util.rkt")
 
   (provide build-dfa print-dfa (struct dfa (num-states start-state final-states/actions transitions)))
 
diff --git a/collects/parser-tools/private-lex/error-tests.rkt b/collects/parser-tools/private-lex/error-tests.rkt
index 0c976601c0..c4afaee621 100644
--- a/collects/parser-tools/private-lex/error-tests.rkt
+++ b/collects/parser-tools/private-lex/error-tests.rkt
@@ -1,6 +1,6 @@
 #lang scheme/base
 (require (for-syntax scheme/base)
-         "../lex.ss"
+         "../lex.rkt"
          rackunit)
 
 (define-syntax (catch-syn-error stx)
diff --git a/collects/parser-tools/private-lex/front.rkt b/collects/parser-tools/private-lex/front.rkt
index da190e10c2..f74c0030ff 100644
--- a/collects/parser-tools/private-lex/front.rkt
+++ b/collects/parser-tools/private-lex/front.rkt
@@ -1,11 +1,11 @@
 (module front mzscheme
   (require (prefix is: mzlib/integer-set)
            mzlib/list
-	   syntax/stx
-           "util.ss"
-           "stx.ss"
-           "re.ss"
-           "deriv.ss")
+           syntax/stx
+           "util.rkt"
+           "stx.rkt"
+           "re.rkt"
+           "deriv.rkt")
   
   (provide build-lexer)
   
diff --git a/collects/parser-tools/private-lex/re.rkt b/collects/parser-tools/private-lex/re.rkt
index 3eaf3a73fe..9da62de83a 100644
--- a/collects/parser-tools/private-lex/re.rkt
+++ b/collects/parser-tools/private-lex/re.rkt
@@ -2,7 +2,7 @@
   (require mzlib/list
            scheme/match
            (prefix is: mzlib/integer-set)
-           "util.ss")
+           "util.rkt")
   
   (provide ->re build-epsilon build-zero build-char-set build-concat
            build-repeat build-or build-and build-neg
diff --git a/collects/parser-tools/private-lex/stx.rkt b/collects/parser-tools/private-lex/stx.rkt
index 37c6bc51c6..83d610ad21 100644
--- a/collects/parser-tools/private-lex/stx.rkt
+++ b/collects/parser-tools/private-lex/stx.rkt
@@ -1,6 +1,6 @@
 (module stx mzscheme
   (require syntax/boundmap
-           "util.ss")
+           "util.rkt")
   
   (provide parse)
 
@@ -32,7 +32,7 @@
   (define (disarm stx)
     (syntax-disarm stx orig-insp))
 
-  ;; parse : syntax-object (box (list-of syntax-object)) -> s-re (see re.ss)
+  ;; parse : syntax-object (box (list-of syntax-object)) -> s-re (see re.rkt)
   ;; checks for errors and generates the plain s-exp form for s
   ;; Expands lex-abbrevs and applies lex-trans.
   (define (parse stx disappeared-uses)
diff --git a/collects/parser-tools/private-lex/token.rkt b/collects/parser-tools/private-lex/token.rkt
index e78467a5e4..1d2dc0d60a 100644
--- a/collects/parser-tools/private-lex/token.rkt
+++ b/collects/parser-tools/private-lex/token.rkt
@@ -1,6 +1,6 @@
 (module token mzscheme
 
-  (require-for-syntax "token-syntax.ss")
+  (require-for-syntax "token-syntax.rkt")
   
   ;; Defining tokens
   
diff --git a/collects/parser-tools/private-lex/unicode-chars.rkt b/collects/parser-tools/private-lex/unicode-chars.rkt
index fb4a134d0f..3177bb5c64 100644
--- a/collects/parser-tools/private-lex/unicode-chars.rkt
+++ b/collects/parser-tools/private-lex/unicode-chars.rkt
@@ -1,5 +1,5 @@
 (module unicode-chars mzscheme
-  (require "util.ss")
+  (require "util.rkt")
   
   (provide (all-defined))
   
diff --git a/collects/parser-tools/private-yacc/grammar.rkt b/collects/parser-tools/private-yacc/grammar.rkt
index fe20c5a361..5b27699093 100644
--- a/collects/parser-tools/private-yacc/grammar.rkt
+++ b/collects/parser-tools/private-yacc/grammar.rkt
@@ -5,7 +5,7 @@
   
   (require mzlib/class
            mzlib/list
-           "yacc-helper.ss"
+           "yacc-helper.rkt"
            mzlib/contract)
   
   ;; Each production has a unique index 0 <= index <= number of productions
diff --git a/collects/parser-tools/private-yacc/input-file-parser.rkt b/collects/parser-tools/private-yacc/input-file-parser.rkt
index 5c6771c94e..68accf4dff 100644
--- a/collects/parser-tools/private-yacc/input-file-parser.rkt
+++ b/collects/parser-tools/private-yacc/input-file-parser.rkt
@@ -1,11 +1,11 @@
 (module input-file-parser mzscheme
 
   ;; routines for parsing the input to the parser generator and producing a
-  ;; grammar (See grammar.ss)
+  ;; grammar (See grammar.rkt)
   
-  (require "yacc-helper.ss"
-           "../private-lex/token-syntax.ss"
-           "grammar.ss"
+  (require "yacc-helper.rkt"
+           "../private-lex/token-syntax.rkt"
+           "grammar.rkt"
            mzlib/class
            mzlib/contract)
   (require-for-template mzscheme)
@@ -57,7 +57,7 @@
         (values args biggest-pos))))
     
   ;; Given the list of terminal symbols and the precedence/associativity definitions,
-  ;; builds terminal structures (See grammar.ss)
+  ;; builds terminal structures (See grammar.rkt)
   ;; build-terms: symbol list * symbol list list -> term list
   (define (build-terms term-list precs)
     (let ((counter 0)
@@ -87,7 +87,7 @@
                     (hash-table-get prec-table term-sym (lambda () #f))))
        term-list)))
   
-  ;; Retrieves the terminal symbols from a terminals-def (See terminal-syntax.ss)
+  ;; Retrieves the terminal symbols from a terminals-def (See terminal-syntax.rkt)
   ;; get-terms-from-def: identifier? -> (listof identifier?)
   (define (get-terms-from-def term-syn)
     (let ((t (syntax-local-value term-syn (lambda () #f))))
diff --git a/collects/parser-tools/private-yacc/lalr.rkt b/collects/parser-tools/private-yacc/lalr.rkt
index 4585c56aef..3fb195334a 100644
--- a/collects/parser-tools/private-yacc/lalr.rkt
+++ b/collects/parser-tools/private-yacc/lalr.rkt
@@ -1,11 +1,11 @@
 (module lalr mzscheme
-  
+
   ;; Compute LALR lookaheads from DeRemer and Pennello 1982
-  
-  (require "lr0.ss"
-	   "grammar.ss"
-	   mzlib/list
-	   mzlib/class)
+
+  (require "lr0.rkt"
+           "grammar.rkt"
+           mzlib/list
+           mzlib/class)
 
   (provide compute-LA)
   
@@ -228,7 +228,7 @@
   ;;     -> (trans-key -> term list)
   ;; DeRemer and Pennello 1982
   ;; Computes (f x) = (f- x) union Union{(f y) | y in (edges x)}
-  ;; A specialization of digraph in the file graph.ss
+  ;; A specialization of digraph in the file graph.rkt
   (define (digraph-tk->terml nodes edges f- num-states)
     (letrec (
 	     ;; Will map elements of trans-key to term sets represented as bit vectors
diff --git a/collects/parser-tools/private-yacc/lr0.rkt b/collects/parser-tools/private-yacc/lr0.rkt
index 6cc5460e2a..ac359ac912 100644
--- a/collects/parser-tools/private-yacc/lr0.rkt
+++ b/collects/parser-tools/private-yacc/lr0.rkt
@@ -2,14 +2,14 @@
 
   ;; Handle the LR0 automaton
   
-  (require "grammar.ss"
-	   "graph.ss"
-	   mzlib/list
-	   mzlib/class)
+  (require "grammar.rkt"
+           "graph.rkt"
+           mzlib/list
+           mzlib/class)
   
   (provide build-lr0-automaton lr0%
-	   (struct trans-key (st gs)) trans-key-list-remove-dups
-	   kernel-items kernel-index)
+           (struct trans-key (st gs)) trans-key-list-remove-dups
+           kernel-items kernel-index)
 
   ;; kernel = (make-kernel (LR1-item list) index)
   ;;   the list must be kept sorted according to item<? so that equal? can
diff --git a/collects/parser-tools/private-yacc/parser-actions.rkt b/collects/parser-tools/private-yacc/parser-actions.rkt
index b06a4e4719..2a39b3617d 100644
--- a/collects/parser-tools/private-yacc/parser-actions.rkt
+++ b/collects/parser-tools/private-yacc/parser-actions.rkt
@@ -1,5 +1,5 @@
 (module parser-actions mzscheme
-  (require "grammar.ss")
+  (require "grammar.rkt")
   (provide (all-defined-except make-reduce make-reduce*)
            (rename make-reduce* make-reduce))
 
diff --git a/collects/parser-tools/private-yacc/parser-builder.rkt b/collects/parser-tools/private-yacc/parser-builder.rkt
index 3b0c09600d..41ebcc297f 100644
--- a/collects/parser-tools/private-yacc/parser-builder.rkt
+++ b/collects/parser-tools/private-yacc/parser-builder.rkt
@@ -1,8 +1,8 @@
 (module parser-builder mzscheme
   
-  (require "input-file-parser.ss"
-           "grammar.ss"
-           "table.ss"
+  (require "input-file-parser.rkt"
+           "grammar.rkt"
+           "table.rkt"
            mzlib/class
            mzlib/contract)
   (require-for-template mzscheme)
@@ -69,7 +69,7 @@
         #`(when #f
             (let ((bind void) ... (tmp void) ...)
               (void bound ... ... term-group ... start ... end ... prec ...))))))
-  (require mzlib/list "parser-actions.ss")
+  (require mzlib/list "parser-actions.rkt")
   (define (build-parser filename src-pos suppress input-terms start end assocs prods)
     (let* ((grammar (parse-input input-terms start end assocs prods src-pos))
            (table (build-table grammar filename suppress))
diff --git a/collects/parser-tools/private-yacc/table.rkt b/collects/parser-tools/private-yacc/table.rkt
index c706db16a3..f3df04181d 100644
--- a/collects/parser-tools/private-yacc/table.rkt
+++ b/collects/parser-tools/private-yacc/table.rkt
@@ -1,14 +1,14 @@
 #lang scheme/base
 
   ;; Routine to build the LALR table
-  
-  (require "grammar.ss"
-	   "lr0.ss"
-	   "lalr.ss"
-	   "parser-actions.ss"
-	   mzlib/contract
+
+  (require "grammar.rkt"
+           "lr0.rkt"
+           "lalr.rkt"
+           "parser-actions.rkt"
+           mzlib/contract
            mzlib/list
-	   mzlib/class)
+           mzlib/class)
 
   (provide/contract 
    (build-table ((is-a?/c grammar%) string? any/c . -> .
diff --git a/collects/parser-tools/private-yacc/yacc-helper.rkt b/collects/parser-tools/private-yacc/yacc-helper.rkt
index 128968e820..31b3cc62ea 100644
--- a/collects/parser-tools/private-yacc/yacc-helper.rkt
+++ b/collects/parser-tools/private-yacc/yacc-helper.rkt
@@ -1,8 +1,8 @@
 (module yacc-helper mzscheme
 
   (require mzlib/list
-           "../private-lex/token-syntax.ss")
-  
+           "../private-lex/token-syntax.rkt")
+
   ;; General helper routines
   
   (provide duplicate-list? remove-duplicates overlap? vector-andmap display-yacc)
diff --git a/collects/parser-tools/yacc.rkt b/collects/parser-tools/yacc.rkt
index b26c711ce2..9a3cc3c649 100644
--- a/collects/parser-tools/yacc.rkt
+++ b/collects/parser-tools/yacc.rkt
@@ -1,19 +1,19 @@
 #lang scheme/base
 
 (require (for-syntax scheme/base
-                     "private-yacc/parser-builder.ss"
-                     "private-yacc/grammar.ss"
-                     "private-yacc/yacc-helper.ss"
-                     "private-yacc/parser-actions.ss"))
-  (require "private-lex/token.ss"
-           "private-yacc/parser-actions.ss"
-           mzlib/etc
-           mzlib/pretty
-	   syntax/readerr)
-  
-  (provide parser)
-  
-    
+                     "private-yacc/parser-builder.rkt"
+                     "private-yacc/grammar.rkt"
+                     "private-yacc/yacc-helper.rkt"
+                     "private-yacc/parser-actions.rkt"))
+(require "private-lex/token.rkt"
+         "private-yacc/parser-actions.rkt"
+         mzlib/etc
+         mzlib/pretty
+         syntax/readerr)
+
+(provide parser)
+
+
   ;; convert-parse-table : (vectorof (listof (cons/c gram-sym? action?))) ->
   ;;                       (vectorof (symbol runtime-action hashtable))
   (define-for-syntax (convert-parse-table table)
@@ -255,7 +255,7 @@
   ;; The table is a vector that maps each state to a hash-table that maps a
   ;; terminal symbol to either an accept, shift, reduce, or goto structure.
   ;  We encode the structures according to the runtime-action data definition in
-  ;; parser-actions.ss
+  ;; parser-actions.rkt
   (define (parser-body debug? err starts ends table all-term-syms actions src-pos)
     (local ((define extract
               (if src-pos
diff --git a/collects/plai/info.rkt b/collects/plai/info.rkt
index 4ba0ff0995..baddcbafed 100644
--- a/collects/plai/info.rkt
+++ b/collects/plai/info.rkt
@@ -2,6 +2,6 @@
 
 (define blurb '("Language levels for the Programming Languages: Application and Interpretation textbook"))
 (define homepage "http://www.cs.brown.edu/~sk/Publications/Books/ProgLangs/")
-(define primary-file "main.ss")
-  
+(define primary-file "main.rkt")
+
 (define scribblings '(("scribblings/plai.scrbl" (multi-page) (teaching -20))))
diff --git a/collects/plai/private/gc-gui.rkt b/collects/plai/private/gc-gui.rkt
index 7248d6951a..61100a8cd8 100644
--- a/collects/plai/private/gc-gui.rkt
+++ b/collects/plai/private/gc-gui.rkt
@@ -1,5 +1,5 @@
 #lang scheme/gui
-(require "gc-core.ss")
+(require "gc-core.rkt")
 (provide heap-viz%)
 
 (define row-size 10)
diff --git a/collects/plai/private/random-mutator.rkt b/collects/plai/private/random-mutator.rkt
index f588d97a63..f888ac54b2 100644
--- a/collects/plai/private/random-mutator.rkt
+++ b/collects/plai/private/random-mutator.rkt
@@ -1,8 +1,8 @@
 #lang scheme/base
-(require scheme/pretty 
-         scheme/match 
+(require scheme/pretty
+         scheme/match
          scheme/contract
-         "gc-core.ss")
+         "gc-core.rkt")
 
 (provide save-random-mutator 
          find-heap-values
diff --git a/collects/plai/random-mutator.rkt b/collects/plai/random-mutator.rkt
index fffbe8c9c6..f3ea2622d4 100644
--- a/collects/plai/random-mutator.rkt
+++ b/collects/plai/random-mutator.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
-(require "private/random-mutator.ss"
+(require "private/random-mutator.rkt"
          scheme/contract
-         "private/gc-core.ss")
+         "private/gc-core.rkt")
 
 (provide/contract
  [save-random-mutator 
diff --git a/collects/planet/config.rkt b/collects/planet/config.rkt
index 7ed18eb660..ec1e2e2a30 100644
--- a/collects/planet/config.rkt
+++ b/collects/planet/config.rkt
@@ -1,5 +1,5 @@
 (module config racket/base
-  (require "private/define-config.ss") 
+  (require "private/define-config.rkt")
   (define-parameters
     (PLANET-SERVER-NAME       "planet.racket-lang.org")
     (PLANET-SERVER-PORT       270)
diff --git a/collects/planet/lang/reader.rkt b/collects/planet/lang/reader.rkt
index 05999916f8..847f560368 100644
--- a/collects/planet/lang/reader.rkt
+++ b/collects/planet/lang/reader.rkt
@@ -1,6 +1,6 @@
 #lang racket/base
 (require syntax/module-reader
-         "../resolver.ss")
+         "../resolver.rkt")
 
 (provide (rename-out [planet-read read]
                      [planet-read-syntax read-syntax]
diff --git a/collects/planet/parsereq.rkt b/collects/planet/parsereq.rkt
index 51419537c0..345d7605cd 100644
--- a/collects/planet/parsereq.rkt
+++ b/collects/planet/parsereq.rkt
@@ -1,8 +1,8 @@
 #lang racket/base
 
 (require mzlib/match
-         "private/short-syntax-helpers.ss"
-         "private/data.ss")
+         "private/short-syntax-helpers.rkt"
+         "private/data.rkt")
 
 (provide (struct-out request)
          parse-package-string
@@ -71,7 +71,7 @@
               [tail (cadr pkg-spec/tail)]
               [fullspec (pkg-spec->full-pkg-spec pkg-spec stx)]
               [final-path (if (string=? tail "")
-                              "main.ss"
+                              "main.rkt"
                               (if (regexp-match #rx"[.]" tail)
                                   tail
                                   (string-append tail ".ss")))])
diff --git a/collects/planet/planet-archives.rkt b/collects/planet/planet-archives.rkt
index dcdfa0c380..69d226da85 100644
--- a/collects/planet/planet-archives.rkt
+++ b/collects/planet/planet-archives.rkt
@@ -1,7 +1,7 @@
 #lang racket/base
-(require "private/planet-shared.ss"
-         "config.ss"
-         "cachepath.ss")
+(require "private/planet-shared.rkt"
+         "config.rkt"
+         "cachepath.rkt")
 
 (provide repository-tree 
          get-installed-planet-archives
diff --git a/collects/planet/private/command.rkt b/collects/planet/private/command.rkt
index b2edbc450c..e41386552c 100644
--- a/collects/planet/private/command.rkt
+++ b/collects/planet/private/command.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-(require "prefix-dispatcher.ss"
+(require "prefix-dispatcher.rkt"
          racket/cmdline
          (for-syntax racket/base))
 
diff --git a/collects/planet/private/linkage.rkt b/collects/planet/private/linkage.rkt
index 8acf97ded8..0be421b9ba 100644
--- a/collects/planet/private/linkage.rkt
+++ b/collects/planet/private/linkage.rkt
@@ -1,7 +1,7 @@
 (module linkage mzscheme
-  
-  (require "planet-shared.ss"
-           "../config.ss"
+
+  (require "planet-shared.rkt"
+           "../config.rkt"
            mzlib/match)
 
   (provide get/linkage
@@ -16,7 +16,7 @@
   ; The first check is to see if there is a valid linkage for the module.
   ; ==========================================================================================
 
-  ;; get/linkage : pkg-getter [see ../resolver.ss]
+  ;; get/linkage : pkg-getter [see ../resolver.rkt]
   ;; getter for the linkage table
   (define (get/linkage rmp pkg-specifier success-k failure-k)
     (let ([linked-pkg (get-linkage rmp pkg-specifier)])
diff --git a/collects/planet/private/planet-shared.rkt b/collects/planet/private/planet-shared.rkt
index 5d3e3f2a81..eabef0f91a 100644
--- a/collects/planet/private/planet-shared.rkt
+++ b/collects/planet/private/planet-shared.rkt
@@ -1,20 +1,20 @@
 #lang racket/base
-#| planet-shared.ss -- shared client/server utility functions
+#| planet-shared.rkt -- shared client/server utility functions
 
 Various common pieces of code that both the client and server need to access
 ==========================================================================================
 |#
   
   (require (only-in mzlib/file path-only)
-	   mzlib/port
+           mzlib/port
            racket/file
            setup/getinfo
            (prefix-in srfi1: srfi/1)
-           "../config.ss"
-           "data.ss")
+           "../config.rkt"
+           "data.rkt")
   
   (provide (all-defined-out)
-           (all-from-out "data.ss")) 
+           (all-from-out "data.rkt"))
   
   ; ==========================================================================================
   ; CACHE LOGIC
@@ -529,7 +529,7 @@ Various common pieces of code that both the client and server need to access
         (close-output-port out))))
   
   ;; pkg->info : PKG -> (symbol (-> TST) -> TST)
-  ;; get an info.ss thunk for the given package
+  ;; get an info.rkt thunk for the given package
   (define (pkg->info p)
     (or
      (with-handlers ([exn:fail? (lambda (e) #f)])
diff --git a/collects/planet/resolver.rkt b/collects/planet/resolver.rkt
index 0166e3f842..b51d4e98d4 100644
--- a/collects/planet/resolver.rkt
+++ b/collects/planet/resolver.rkt
@@ -1,6 +1,6 @@
 #lang mzscheme
 
-#| resolver.ss -- PLaneT client
+#| resolver.rkt -- PLaneT client
 
 1. Introduction
 
@@ -194,13 +194,13 @@ subdirectory.
          net/head
          mzlib/struct
 
-         "config.ss"
-         "private/planet-shared.ss"
-         "private/linkage.ss"
-         "parsereq.ss"
-         
-         "terse-info.ss"
-         compiler/cm) 
+         "config.rkt"
+         "private/planet-shared.rkt"
+         "private/linkage.rkt"
+         "parsereq.rkt"
+
+         "terse-info.rkt"
+         compiler/cm)
 
 (provide (rename resolver planet-module-name-resolver)
          resolve-planet-path
diff --git a/collects/plot/extend.rkt b/collects/plot/extend.rkt
index e4c4ec113e..ab0c053c65 100644
--- a/collects/plot/extend.rkt
+++ b/collects/plot/extend.rkt
@@ -1,10 +1,10 @@
 #lang scheme/base
 
-(require "plot-extend.ss"
-         "renderer-helpers.ss"
-         "view.ss")
+(require "plot-extend.rkt"
+         "renderer-helpers.rkt"
+         "view.rkt")
 
-(provide (except-out (all-from-out "plot-extend.ss")
+(provide (except-out (all-from-out "plot-extend.rkt")
                      define-plot-type)
          plot-view%
 
diff --git a/collects/plot/main.rkt b/collects/plot/main.rkt
index 0652eee6d3..7f14bef620 100644
--- a/collects/plot/main.rkt
+++ b/collects/plot/main.rkt
@@ -1,16 +1,16 @@
 #lang scheme/base
 
-(require (prefix-in orig: 
-                    (only-in "plot.ss"
+(require (prefix-in orig:
+                    (only-in "plot.rkt"
                              plot plot3d
                              points line error-bars
                              vector-field contour
                              shade surface))
-         (only-in "plot.ss"
+         (only-in "plot.rkt"
                   mix
                   derivative gradient make-vec
                   mesh3d)
-         (only-in "fit.ss" fit-int))
+         (only-in "fit.rkt" fit-int))
 
 (provide plot
          plot3d
@@ -31,7 +31,7 @@
 
 (define-syntax-rule (out-fit-struct)
   (begin
-    (require "plot.ss")
+    (require "plot.rkt")
     (provide (struct-out fit-result))))
 
 (out-fit-struct)
diff --git a/collects/plot/plot.rkt b/collects/plot/plot.rkt
index 87250389bf..81410a9d74 100644
--- a/collects/plot/plot.rkt
+++ b/collects/plot/plot.rkt
@@ -1,7 +1,7 @@
 #lang mzscheme
 
 (require mzlib/list mzlib/etc mzlib/class
-         "math.ss" "view.ss" "renderer-helpers.ss" "renderers.ss" "fit.ss")
+         "math.rkt" "view.rkt" "renderer-helpers.rkt" "renderers.rkt" "fit.rkt")
 
 ;; plot : plottable (option value)*
 (define-syntax plot
diff --git a/collects/preprocessor/info.rkt b/collects/preprocessor/info.rkt
index 3d9b3f1e18..91dd7a2fed 100644
--- a/collects/preprocessor/info.rkt
+++ b/collects/preprocessor/info.rkt
@@ -1,6 +1,6 @@
 #lang setup/infotab
 
-(define mzscheme-launcher-names     '("mzpp"        "mztext"))
-(define mzscheme-launcher-libraries '("mzpp-run.ss" "mztext-run.ss"))
+(define mzscheme-launcher-names     '("mzpp"         "mztext"))
+(define mzscheme-launcher-libraries '("mzpp-run.rkt" "mztext-run.rkt"))
 
 (define scribblings '(("scribblings/preprocessor.scrbl" (multi-page) (legacy))))
diff --git a/collects/profile/analyzer.rkt b/collects/profile/analyzer.rkt
index 664aee7f55..e114c4e369 100644
--- a/collects/profile/analyzer.rkt
+++ b/collects/profile/analyzer.rkt
@@ -4,7 +4,7 @@
 
 (provide analyze-samples)
 
-(require "structs.ss" "utils.ss" scheme/list)
+(require "structs.rkt" "utils.rkt" scheme/list)
 
 (define-syntax-rule (with-hash <hash> <key> <expr>)
   (hash-ref! <hash> <key> (lambda () <expr>)))
diff --git a/collects/profile/main.rkt b/collects/profile/main.rkt
index 3c29bf0b3d..af103813fb 100644
--- a/collects/profile/main.rkt
+++ b/collects/profile/main.rkt
@@ -2,8 +2,8 @@
 
 (provide profile-thunk profile)
 
-(require "sampler.ss" "analyzer.ss"
-         (prefix-in text: "render-text.ss")
+(require "sampler.rkt" "analyzer.rkt"
+         (prefix-in text: "render-text.rkt")
          (for-syntax scheme/base))
 
 (define (profile-thunk thunk
@@ -74,7 +74,7 @@
   (thread bg-fib)
   (list (fibs n) (channel-get ch)))
 
-(require "render-graphviz.ss")
+(require "render-graphviz.rkt")
 
 (profile ;(fibs 40)
          ;(dynamic-require '(lib "scribblings/reference/reference.scrbl") #f)
diff --git a/collects/profile/render-graphviz.rkt b/collects/profile/render-graphviz.rkt
index 946a15f0d9..1aba7cea6c 100644
--- a/collects/profile/render-graphviz.rkt
+++ b/collects/profile/render-graphviz.rkt
@@ -2,7 +2,7 @@
 
 (provide render)
 
-(require "structs.ss" "analyzer.ss" "utils.ss")
+(require "structs.rkt" "analyzer.rkt" "utils.rkt")
 
 (define (render profile
                 #:hide-self [hide-self% 1/100]
diff --git a/collects/profile/render-text.rkt b/collects/profile/render-text.rkt
index 8cda73accb..a0952fcf0d 100644
--- a/collects/profile/render-text.rkt
+++ b/collects/profile/render-text.rkt
@@ -2,7 +2,7 @@
 
 (provide render)
 
-(require "structs.ss" "analyzer.ss" "utils.ss" scheme/list)
+(require "structs.rkt" "analyzer.rkt" "utils.rkt" scheme/list)
 
 (define (f:msec msec)
   (number->string (round (inexact->exact msec))))
diff --git a/collects/profile/utils.rkt b/collects/profile/utils.rkt
index f355340442..7486ce3b30 100644
--- a/collects/profile/utils.rkt
+++ b/collects/profile/utils.rkt
@@ -1,6 +1,6 @@
 #lang scheme/base
 
-(require "structs.ss" scheme/list scheme/nest)
+(require "structs.rkt" scheme/list scheme/nest)
 
 ;; Format a percent number, possibly doing the division too.  If we do the
 ;; division, then be careful: if we're dividing by zero, then make the result
diff --git a/collects/r5rs/info.rkt b/collects/r5rs/info.rkt
index 70e304f32d..85e66891a5 100644
--- a/collects/r5rs/info.rkt
+++ b/collects/r5rs/info.rkt
@@ -3,4 +3,4 @@
 (define scribblings '(("r5rs.scrbl" (multi-page) (legacy 50))))
 
 (define mzscheme-launcher-names '("PLT R5RS"))
-(define mzscheme-launcher-libraries '("run.ss"))
+(define mzscheme-launcher-libraries '("run.rkt"))
diff --git a/collects/r5rs/init.rkt b/collects/r5rs/init.rkt
index 6ecb157a4e..cb98484197 100644
--- a/collects/r5rs/init.rkt
+++ b/collects/r5rs/init.rkt
@@ -12,6 +12,6 @@
 (define-syntax out
   (syntax-rules ()
     [(_) (begin
-           (require "main.ss")
-           (provide (all-from-out "main.ss")))]))
+           (require "main.rkt")
+           (provide (all-from-out "main.rkt")))]))
 (out)
diff --git a/collects/r5rs/lang.rkt b/collects/r5rs/lang.rkt
index 9cd805154e..eee7f80c00 100644
--- a/collects/r5rs/lang.rkt
+++ b/collects/r5rs/lang.rkt
@@ -1,5 +1,4 @@
-
-;; For backward compatibility. Use "main.ss", instead.
+;; For backward compatibility. Use "main.rkt", instead.
 
 (module lang r5rs
   (#%provide (all-from r5rs)))
diff --git a/collects/r5rs/main.rkt b/collects/r5rs/main.rkt
index e0650d87dd..c7f175edfa 100644
--- a/collects/r5rs/main.rkt
+++ b/collects/r5rs/main.rkt
@@ -1,8 +1,7 @@
-
 (module main scheme/base
   (require scheme/mpair
            (for-syntax scheme/base syntax/kerncase
-                       "private/r5rs-trans.ss")
+                       "private/r5rs-trans.rkt")
            (only-in mzscheme transcript-on transcript-off))
 
   (provide (for-syntax syntax-rules ...
diff --git a/collects/r5rs/r5rs.rkt b/collects/r5rs/r5rs.rkt
index f823bf7941..39b322bcab 100644
--- a/collects/r5rs/r5rs.rkt
+++ b/collects/r5rs/r5rs.rkt
@@ -1,3 +1,3 @@
-(module r5rs "main.ss"
+(module r5rs "main.rkt"
   (#%require (only scheme/base provide all-from-out))
-  (provide (all-from-out "main.ss")))
+  (provide (all-from-out "main.rkt")))
diff --git a/collects/r6rs/info.rkt b/collects/r6rs/info.rkt
index e4b1143ab2..eb48bbe24b 100644
--- a/collects/r6rs/info.rkt
+++ b/collects/r6rs/info.rkt
@@ -3,4 +3,4 @@
 (define scribblings '(("scribblings/r6rs.scrbl" (multi-page) (language 1))))
 
 (define mzscheme-launcher-names '("PLT R6RS"))
-(define mzscheme-launcher-libraries '("run.ss"))
+(define mzscheme-launcher-libraries '("run.rkt"))
diff --git a/collects/r6rs/lang/reader.rkt b/collects/r6rs/lang/reader.rkt
index 559dfe7c5e..06222a0f24 100644
--- a/collects/r6rs/lang/reader.rkt
+++ b/collects/r6rs/lang/reader.rkt
@@ -5,4 +5,4 @@ r6rs
 #:wrapper1 with-r6rs-reader-parameters
 #:language-info '#(scheme/language-info get-info #f)
 
-(require "../private/readtable.ss")
+(require "../private/readtable.rkt")
diff --git a/collects/r6rs/main.rkt b/collects/r6rs/main.rkt
index 885fb7dc50..d4dd0dcb13 100644
--- a/collects/r6rs/main.rkt
+++ b/collects/r6rs/main.rkt
@@ -8,9 +8,9 @@ FIXME:
 
 (require (for-syntax scheme/base
                      syntax/kerncase
-                     "private/parse-ref.ss"
+                     "private/parse-ref.rkt"
                      scheme/provide-transform)
-         "private/no-set.ss")
+         "private/no-set.rkt")
 
 (provide (rename-out [module-begin #%module-begin]))
 
diff --git a/collects/r6rs/private/base-for-syntax.rkt b/collects/r6rs/private/base-for-syntax.rkt
index 58883de1cc..1708e4d41c 100644
--- a/collects/r6rs/private/base-for-syntax.rkt
+++ b/collects/r6rs/private/base-for-syntax.rkt
@@ -6,7 +6,7 @@
 
 (require r6rs/private/identifier-syntax
          (for-syntax scheme/base
-                     "check-pattern.ss"))
+                     "check-pattern.rkt"))
 
 (provide (rename-out [r6rs:syntax-rules syntax-rules])
          identifier-syntax
diff --git a/collects/r6rs/private/conds.rkt b/collects/r6rs/private/conds.rkt
index 059b63cf16..c2ef7a3244 100644
--- a/collects/r6rs/private/conds.rkt
+++ b/collects/r6rs/private/conds.rkt
@@ -3,7 +3,7 @@
 (require rnrs/records/syntactic-6
          rnrs/records/procedural-6
          scheme/mpair
-         "exns.ss"
+         "exns.rkt"
          (for-syntax scheme/base))
 
 (provide &condition
diff --git a/collects/r6rs/private/identifier-syntax.rkt b/collects/r6rs/private/identifier-syntax.rkt
index dfc87c79e3..8680c30adb 100644
--- a/collects/r6rs/private/identifier-syntax.rkt
+++ b/collects/r6rs/private/identifier-syntax.rkt
@@ -1,6 +1,6 @@
 #lang scheme/base
 (require (for-syntax scheme/base)
-         (for-template "no-set.ss"
+         (for-template "no-set.rkt"
                        (only-in scheme/base #%app set!)))
 
 (provide identifier-syntax)
diff --git a/collects/r6rs/private/parse-ref.rkt b/collects/r6rs/private/parse-ref.rkt
index 47841d4a86..67ac578800 100644
--- a/collects/r6rs/private/parse-ref.rkt
+++ b/collects/r6rs/private/parse-ref.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 
-(require "find-version.ss"
-         "encode-name.ss"
+(require "find-version.rkt"
+         "encode-name.rkt"
          (for-template scheme/base))
 
 (provide parse-import)
diff --git a/collects/r6rs/run.rkt b/collects/r6rs/run.rkt
index 2b3b7c330e..d7cb285300 100644
--- a/collects/r6rs/run.rkt
+++ b/collects/r6rs/run.rkt
@@ -1,13 +1,13 @@
 #lang scheme/base
 (require scheme/cmdline
          compiler/cm
-         (prefix-in r6rs: "lang/reader.ss")
+         (prefix-in r6rs: "lang/reader.rkt")
          syntax/modcode
          setup/dirs
          scheme/port
          scheme/file
-         "private/readtable.ss"
-         "private/encode-name.ss")
+         "private/readtable.rkt"
+         "private/encode-name.rkt")
 
 (define install-mode (make-parameter #f))
 (define compile-mode (make-parameter #f))
diff --git a/collects/racket/contract/private/vector.rkt b/collects/racket/contract/private/vector.rkt
index 0f30b4d1bb..94f8c3334c 100644
--- a/collects/racket/contract/private/vector.rkt
+++ b/collects/racket/contract/private/vector.rkt
@@ -1,7 +1,7 @@
 #lang racket/base
 
 (require (for-syntax racket/base)
-         "guts.ss"
+         "guts.rkt"
          "prop.rkt"
          "blame.rkt"
          "misc.rkt")
diff --git a/collects/racket/draw/private/brush.rkt b/collects/racket/draw/private/brush.rkt
index 84dabf402d..a57d3b8ba9 100644
--- a/collects/racket/draw/private/brush.rkt
+++ b/collects/racket/draw/private/brush.rkt
@@ -1,10 +1,10 @@
 #lang scheme/base
 (require scheme/class
          ffi/unsafe/atomic
-         "color.ss"
-         "syntax.ss"
-         "local.ss"
-         "bitmap.ss"
+         "color.rkt"
+         "syntax.rkt"
+         "local.rkt"
+         "bitmap.rkt"
          "gradient.rkt")
 
 (provide brush%
diff --git a/collects/racket/draw/private/color.rkt b/collects/racket/draw/private/color.rkt
index e92af55784..1142660d1f 100644
--- a/collects/racket/draw/private/color.rkt
+++ b/collects/racket/draw/private/color.rkt
@@ -1,6 +1,6 @@
 #lang scheme/base
 (require scheme/class
-         "syntax.ss")
+         "syntax.rkt")
 
 (provide color%
          color-red
diff --git a/collects/racket/draw/private/dc-intf.rkt b/collects/racket/draw/private/dc-intf.rkt
index 2af154f8a0..d2583b85cb 100644
--- a/collects/racket/draw/private/dc-intf.rkt
+++ b/collects/racket/draw/private/dc-intf.rkt
@@ -1,6 +1,6 @@
 #lang scheme/base
 (require scheme/class
-         "font.ss")
+         "font.rkt")
 
 (provide dc<%>)
 
diff --git a/collects/racket/draw/private/dc-path.rkt b/collects/racket/draw/private/dc-path.rkt
index 44071329ee..65f126f9bf 100644
--- a/collects/racket/draw/private/dc-path.rkt
+++ b/collects/racket/draw/private/dc-path.rkt
@@ -3,9 +3,9 @@
 (require "syntax.rkt"
          scheme/math
          scheme/class
-         "../unsafe/cairo.ss"
-         "fmod.ss"
-         "point.ss"
+         "../unsafe/cairo.rkt"
+         "fmod.rkt"
+         "point.rkt"
          (only-in scheme/base 
                   [append s:append]
                   [reverse s:reverse]))
diff --git a/collects/racket/draw/private/dc.rkt b/collects/racket/draw/private/dc.rkt
index c1ae0c7726..abd5bb7750 100644
--- a/collects/racket/draw/private/dc.rkt
+++ b/collects/racket/draw/private/dc.rkt
@@ -7,21 +7,21 @@
          ffi/unsafe/atomic
          racket/math
          racket/class
-         "hold.ss"
-         "local.ss"
-         "../unsafe/cairo.ss"
-         "../unsafe/pango.ss"
-         "color.ss"
-         "pen.ss"
-         "brush.ss"
-         "gradient.ss"
-         "font.ss"
-         "bitmap.ss"
-         "region.ss"
-         "dc-intf.ss"
-         "dc-path.ss"
-         "point.ss"
-         "local.ss"
+         "hold.rkt"
+         "local.rkt"
+         "../unsafe/cairo.rkt"
+         "../unsafe/pango.rkt"
+         "color.rkt"
+         "pen.rkt"
+         "brush.rkt"
+         "gradient.rkt"
+         "font.rkt"
+         "bitmap.rkt"
+         "region.rkt"
+         "dc-intf.rkt"
+         "dc-path.rkt"
+         "point.rkt"
+         "local.rkt"
          "../unsafe/bstr.rkt")
 
 (provide dc-mixin
diff --git a/collects/racket/draw/private/font.rkt b/collects/racket/draw/private/font.rkt
index 2f88185e30..c0a92d8e4a 100644
--- a/collects/racket/draw/private/font.rkt
+++ b/collects/racket/draw/private/font.rkt
@@ -2,13 +2,13 @@
 (require scheme/class
          ffi/unsafe
          ffi/unsafe/atomic
-         "syntax.ss"
-         "../unsafe/pango.ss"
-         "../unsafe/cairo.ss"
-         "font-syms.ss"
-         "font-dir.ss"
-         "local.ss"
-	 "xp.rkt")
+         "syntax.rkt"
+         "../unsafe/pango.rkt"
+         "../unsafe/cairo.rkt"
+         "font-syms.rkt"
+         "font-dir.rkt"
+         "local.rkt"
+         "xp.rkt")
 
 (provide font%
          font-list% the-font-list
diff --git a/collects/racket/draw/private/pen.rkt b/collects/racket/draw/private/pen.rkt
index 7539c4a3b1..e9fea0cc4d 100644
--- a/collects/racket/draw/private/pen.rkt
+++ b/collects/racket/draw/private/pen.rkt
@@ -1,10 +1,10 @@
 #lang scheme/base
 (require scheme/class
          ffi/unsafe/atomic
-         "color.ss"
-         "syntax.ss"
-         "local.ss"
-         "bitmap.ss")
+         "color.rkt"
+         "syntax.rkt"
+         "local.rkt"
+         "bitmap.rkt")
 
 (provide pen%
          pen-list% the-pen-list
diff --git a/collects/racket/draw/private/post-script-dc.rkt b/collects/racket/draw/private/post-script-dc.rkt
index 9a73850c42..d1e53b3316 100644
--- a/collects/racket/draw/private/post-script-dc.rkt
+++ b/collects/racket/draw/private/post-script-dc.rkt
@@ -6,11 +6,11 @@
          "syntax.rkt"
          racket/gui/dynamic
          ffi/unsafe
-         "../unsafe/cairo.ss"
-	 "dc.ss"
-         "font.ss"
-         "local.ss"
-         "ps-setup.ss"
+         "../unsafe/cairo.rkt"
+         "dc.rkt"
+         "font.rkt"
+         "local.rkt"
+         "ps-setup.rkt"
          "page-dc.rkt"
          "write-bytes.rkt")
 
diff --git a/collects/racket/draw/private/record-dc.rkt b/collects/racket/draw/private/record-dc.rkt
index 45b164f2ee..8ab577778d 100644
--- a/collects/racket/draw/private/record-dc.rkt
+++ b/collects/racket/draw/private/record-dc.rkt
@@ -11,7 +11,7 @@
          "brush.rkt"
          "region.rkt"
          "dc-path.rkt"
-         "local.ss")
+         "local.rkt")
 
 (provide record-dc-mixin
          get-recorded-command
diff --git a/collects/racket/draw/private/region.rkt b/collects/racket/draw/private/region.rkt
index c4d4a3f363..f4bc18c0f9 100644
--- a/collects/racket/draw/private/region.rkt
+++ b/collects/racket/draw/private/region.rkt
@@ -1,12 +1,12 @@
 #lang scheme/base
 (require scheme/class
          ffi/unsafe/atomic
-         "syntax.ss"
-         "local.ss"
-         "../unsafe/cairo.ss"
-         "dc-path.ss"
-         "dc-intf.ss"
-         "point.ss")
+         "syntax.rkt"
+         "local.rkt"
+         "../unsafe/cairo.rkt"
+         "dc-path.rkt"
+         "dc-intf.rkt"
+         "point.rkt")
 
 (provide region%
 
diff --git a/collects/racket/draw/private/svg-dc.rkt b/collects/racket/draw/private/svg-dc.rkt
index 7feb052de8..33b96564c8 100644
--- a/collects/racket/draw/private/svg-dc.rkt
+++ b/collects/racket/draw/private/svg-dc.rkt
@@ -5,11 +5,11 @@
          racket/math
          "syntax.rkt"
          ffi/unsafe
-         "../unsafe/cairo.ss"
-	 "dc.ss"
-         "font.ss"
-         "local.ss"
-         "ps-setup.ss"
+         "../unsafe/cairo.rkt"
+         "dc.rkt"
+         "font.rkt"
+         "local.rkt"
+         "ps-setup.rkt"
          "page-dc.rkt"
          "write-bytes.rkt")
 
diff --git a/collects/racket/draw/private/write-bytes.rkt b/collects/racket/draw/private/write-bytes.rkt
index ee03ed5d8d..856668f4a1 100644
--- a/collects/racket/draw/private/write-bytes.rkt
+++ b/collects/racket/draw/private/write-bytes.rkt
@@ -1,8 +1,8 @@
 #lang racket/base
 (require ffi/unsafe
          ffi/unsafe/alloc
-         "../unsafe/cairo.ss"
-         "../unsafe/bstr.ss")
+         "../unsafe/cairo.rkt"
+         "../unsafe/bstr.rkt")
 
 (provide make-port-writer
          port-writer-wait)
diff --git a/collects/racket/math.rkt b/collects/racket/math.rkt
index 7b6c7a504d..5aa72bd4a3 100644
--- a/collects/racket/math.rkt
+++ b/collects/racket/math.rkt
@@ -1,6 +1,6 @@
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;
-;; math.ss: some extra math routines
+;; math.rkt: some extra math routines
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 #lang scheme/base
@@ -66,7 +66,7 @@
 
 ;;; Tests and timings of order-of-magnitude
 
-(require "order-of-magnitude.ss")
+(require "order-of-magnitude.rkt")
 (require (planet joskoot/planet-fmt:1:1/fmt))
 
 (define-syntax timer
diff --git a/collects/racket/private/class-internal.rkt b/collects/racket/private/class-internal.rkt
index 03eb956cdd..9c370bc30f 100644
--- a/collects/racket/private/class-internal.rkt
+++ b/collects/racket/private/class-internal.rkt
@@ -1262,7 +1262,7 @@
                                     [(plain-init-name-localized ...) (map lookup-localize plain-init-names)]
                                     [(local-plain-init-name ...) (generate-temporaries plain-init-names)])
                         (let ([mappings
-                               ;; make-XXX-map is supplied by private/classidmap.ss
+                               ;; make-XXX-map is supplied by private/classidmap.rkt
                                (with-syntax ([the-obj the-obj]
                                              [the-finder the-finder]
                                              [this-id this-id]
diff --git a/collects/racket/private/define-struct.rkt b/collects/racket/private/define-struct.rkt
index 981cd03909..03559b5ece 100644
--- a/collects/racket/private/define-struct.rkt
+++ b/collects/racket/private/define-struct.rkt
@@ -1,4 +1,3 @@
-
 ;; Based on
 ;;  (planet "struct.ss" ("ryanc" "macros.plt" 1 0)))
 
diff --git a/collects/racket/sandbox.rkt b/collects/racket/sandbox.rkt
index 9a3d7069e0..30520357d5 100644
--- a/collects/racket/sandbox.rkt
+++ b/collects/racket/sandbox.rkt
@@ -529,9 +529,9 @@
               (= 2 (length language))
               (eq? (car language) 'special)
               (memq (cadr language) teaching-langs))
-         `(lib ,(format "htdp-~a.ss" (cadr language)) "lang")]
+         `(lib ,(format "htdp-~a.rkt" (cadr language)) "lang")]
         [(equal? language '(special r5rs))
-         `(lib "lang.ss" "r5rs")]
+         `(lib "lang.rkt" "r5rs")]
         [else #f]))
 
 ;; Like a toplevel (eval `(begin ,@exprs)), but the language that is used may
@@ -553,9 +553,9 @@
 
 ;; We need a powerful enough code inspector to invoke the errortrace library
 ;; (indirectly through private/sandbox-coverage).  But there is a small problem
-;; here -- errortrace/stacktrace.ss will grab the global code inspector value
+;; here -- errortrace/stacktrace.rkt will grab the global code inspector value
 ;; at the time it is invoked.  So we grab it here too, and use it to wrap the
-;; code that invokes errortrace.  If errortrace/stacktrace.ss is changed to
+;; code that invokes errortrace.  If errortrace/stacktrace.rkt is changed to
 ;; grab the current inspector, then it would be better to avoid this here, and
 ;; pass `evaluate-program' the inspector that was in effect when the sandbox
 ;; was created.
diff --git a/collects/racket/snip/private/snip-admin.rkt b/collects/racket/snip/private/snip-admin.rkt
index 87dda1561d..64a33f0fcd 100644
--- a/collects/racket/snip/private/snip-admin.rkt
+++ b/collects/racket/snip/private/snip-admin.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 (require scheme/class
          racket/draw/private/syntax
-         "snip.ss")
+         "snip.rkt")
 
 (provide snip-admin%)
 
diff --git a/collects/racket/snip/private/snip.rkt b/collects/racket/snip/private/snip.rkt
index 1bcd4f27dc..839111f080 100644
--- a/collects/racket/snip/private/snip.rkt
+++ b/collects/racket/snip/private/snip.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 (require scheme/class
          scheme/file file/convertible
-         "snip-flags.ss"
+         "snip-flags.rkt"
          "load-one.rkt"
          "style.rkt"
          "private.rkt"
diff --git a/collects/raco/main.rkt b/collects/raco/main.rkt
index 335ed7c379..fe31bb59b8 100644
--- a/collects/raco/main.rkt
+++ b/collects/raco/main.rkt
@@ -1,9 +1,8 @@
-
 ;; Because `raco setup' is used to rebuild .zos, check for "setup"
 ;; directly.
 
-;; Note that this file is listed in "info.ss" so that it never gets a
-;; .zo file. Do not `require' this module from anywhere, not even 
+;; Note that this file is listed in "info.rkt" so that it never gets a
+;; .zo file. Do not `require' this module from anywhere, not even
 ;; `for-label', otherwise it could get a .zo anyway.
 
 (module main '#%kernel
diff --git a/collects/raco/raco.rkt b/collects/raco/raco.rkt
index ac2a63636d..9b313155ee 100644
--- a/collects/raco/raco.rkt
+++ b/collects/raco/raco.rkt
@@ -1,6 +1,6 @@
 #lang scheme/base
-(require "command-name.ss"
-         "all-tools.ss")
+(require "command-name.rkt"
+         "all-tools.rkt")
 
 (define (find-by-prefix hash str)
   (let ([trie (make-hash)])
diff --git a/collects/readline/main.rkt b/collects/readline/main.rkt
index 2c2221189c..fd2b15978e 100644
--- a/collects/readline/main.rkt
+++ b/collects/readline/main.rkt
@@ -1,4 +1,4 @@
 #lang scheme
 
-(require "rep.ss")
-(provide (all-from-out "rep.ss"))
+(require "rep.rkt")
+(provide (all-from-out "rep.rkt"))
diff --git a/collects/readline/pread.rkt b/collects/readline/pread.rkt
index 1ceb1752cd..a30a6d8765 100644
--- a/collects/readline/pread.rkt
+++ b/collects/readline/pread.rkt
@@ -1,6 +1,6 @@
 #lang scheme/base
 
-(require "mzrl.ss" scheme/list scheme/file)
+(require "mzrl.rkt" scheme/list scheme/file)
 
 ;; --------------------------------------------------------------------------
 ;; Configuration
diff --git a/collects/readline/readline.rkt b/collects/readline/readline.rkt
index 54e6677bc9..7fb2e6c92c 100644
--- a/collects/readline/readline.rkt
+++ b/collects/readline/readline.rkt
@@ -1,4 +1,3 @@
-
 (module readline mzscheme
-  (require "mzrl.ss")
-  (provide (all-from "mzrl.ss")))
+  (require "mzrl.rkt")
+  (provide (all-from "mzrl.rkt")))
diff --git a/collects/readline/rep-start.rkt b/collects/readline/rep-start.rkt
index e32e0e125e..1bc6ba2f4a 100644
--- a/collects/readline/rep-start.rkt
+++ b/collects/readline/rep-start.rkt
@@ -1,9 +1,9 @@
-;; This module initializes readline unconditionally, "rep.ss" uses it if we're
+;; This module initializes readline unconditionally, "rep.rkt" uses it if we're
 ;; using a `terminal-port?' for input.
 
 #lang scheme/base
 
-(require "pread.ss")
+(require "pread.rkt")
 
 ;; Change the input port and readline-prompt hook
 (current-input-port readline-input)
diff --git a/collects/readline/rep.rkt b/collects/readline/rep.rkt
index aadeb5e91d..e915b320e0 100644
--- a/collects/readline/rep.rkt
+++ b/collects/readline/rep.rkt
@@ -1,9 +1,9 @@
-;; This is a wrapper around "rep-start.ss" -- use it if we're using a terminal
+;; This is a wrapper around "rep-start.rkt" -- use it if we're using a terminal
 #lang scheme/base
 
 (require scheme/runtime-path scheme/file)
 
-(define-runtime-path rep-start "rep-start.ss")
+(define-runtime-path rep-start "rep-start.rkt")
 
 (provide install-readline!)
 
diff --git a/collects/redex/examples/delim-cont/meta.rkt b/collects/redex/examples/delim-cont/meta.rkt
index 569c2ef592..3a1eb49d6d 100644
--- a/collects/redex/examples/delim-cont/meta.rkt
+++ b/collects/redex/examples/delim-cont/meta.rkt
@@ -1,7 +1,7 @@
 #lang racket
 
 (require redex/reduction-semantics
-         "grammar.ss")
+         "grammar.rkt")
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Substitution:
diff --git a/collects/redex/examples/delim-cont/randomized-tests.rkt b/collects/redex/examples/delim-cont/randomized-tests.rkt
index ae91bb4f93..2e71d36b19 100644
--- a/collects/redex/examples/delim-cont/randomized-tests.rkt
+++ b/collects/redex/examples/delim-cont/randomized-tests.rkt
@@ -1,6 +1,6 @@
 #lang racket
 
-(require "grammar.ss" 
+(require "grammar.rkt"
          "reduce.rkt"
          (except-in redex/reduction-semantics plug)
          racket/runtime-path)
diff --git a/collects/redex/examples/delim-cont/reduce.rkt b/collects/redex/examples/delim-cont/reduce.rkt
index 5628c2add1..4ef453e5b0 100644
--- a/collects/redex/examples/delim-cont/reduce.rkt
+++ b/collects/redex/examples/delim-cont/reduce.rkt
@@ -1,8 +1,8 @@
 #lang racket
 
 (require redex/reduction-semantics
-         "grammar.ss"
-         "meta.ss")
+         "grammar.rkt"
+         "meta.rkt")
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Reductions:
diff --git a/collects/redex/examples/delim-cont/test.rkt b/collects/redex/examples/delim-cont/test.rkt
index be2f9bcdf5..786a15a835 100644
--- a/collects/redex/examples/delim-cont/test.rkt
+++ b/collects/redex/examples/delim-cont/test.rkt
@@ -1,9 +1,9 @@
 #lang racket
 
 (require redex
-         "grammar.ss"
-         "meta.ss"
-         "reduce.ss")
+         "grammar.rkt"
+         "meta.rkt"
+         "reduce.rkt")
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Abbreviations:
diff --git a/collects/redex/examples/letrec.rkt b/collects/redex/examples/letrec.rkt
index 40ea593ab7..afc91faacf 100644
--- a/collects/redex/examples/letrec.rkt
+++ b/collects/redex/examples/letrec.rkt
@@ -6,7 +6,7 @@ BUG: letrec & let are not handled properly by substitution
 
 |#
 
-(require redex "subst.ss")
+(require redex "subst.rkt")
 
 (reduction-steps-cutoff 20)
 
diff --git a/collects/redex/examples/omega.rkt b/collects/redex/examples/omega.rkt
index 63e5967324..0164b88d4e 100644
--- a/collects/redex/examples/omega.rkt
+++ b/collects/redex/examples/omega.rkt
@@ -1,5 +1,5 @@
 #lang racket
-(require redex "subst.ss")
+(require redex "subst.rkt")
 
 (reduction-steps-cutoff 10)
 
diff --git a/collects/redex/examples/r6rs/r6rs-tests.rkt b/collects/redex/examples/r6rs/r6rs-tests.rkt
index 54811effaf..d2738f2483 100644
--- a/collects/redex/examples/r6rs/r6rs-tests.rkt
+++ b/collects/redex/examples/r6rs/r6rs-tests.rkt
@@ -2,8 +2,8 @@
 (require racket/match
          redex/reduction-semantics
          (for-syntax racket/base)
-         "test.ss"
-         "r6rs.ss")
+         "test.rkt"
+         "r6rs.rkt")
 
 ;; ============================================================
 ;; TESTING APPARATUS
diff --git a/collects/redex/examples/r6rs/show-examples.rkt b/collects/redex/examples/r6rs/show-examples.rkt
index 00190352dc..5a13850afc 100644
--- a/collects/redex/examples/r6rs/show-examples.rkt
+++ b/collects/redex/examples/r6rs/show-examples.rkt
@@ -1,7 +1,7 @@
 #lang racket
 
 (require redex
-         "r6rs.ss")
+         "r6rs.rkt")
 (provide show show-expression
          step step-expression)
 
diff --git a/collects/redex/examples/racket-machine/reduction-test.rkt b/collects/redex/examples/racket-machine/reduction-test.rkt
index 5b38cf35d6..621c0dfc5a 100644
--- a/collects/redex/examples/racket-machine/reduction-test.rkt
+++ b/collects/redex/examples/racket-machine/reduction-test.rkt
@@ -1,7 +1,7 @@
 #lang racket
 
 (require redex/reduction-semantics
-         "reduction.ss")
+         "reduction.rkt")
 
 ;                                                                                             
 ;                                                                                             
diff --git a/collects/redex/examples/racket-machine/reduction.rkt b/collects/redex/examples/racket-machine/reduction.rkt
index f90bab776e..17d0303dd4 100644
--- a/collects/redex/examples/racket-machine/reduction.rkt
+++ b/collects/redex/examples/racket-machine/reduction.rkt
@@ -1,7 +1,7 @@
 #lang racket
 
 (require redex/reduction-semantics)
-(require "grammar.ss" "util.ss")
+(require "grammar.rkt" "util.rkt")
 
 (define-extended-language runtime bytecode
   (p (V S H T C) error)
diff --git a/collects/redex/examples/racket-machine/util.rkt b/collects/redex/examples/racket-machine/util.rkt
index 8f4a51f6e2..a582c5e630 100644
--- a/collects/redex/examples/racket-machine/util.rkt
+++ b/collects/redex/examples/racket-machine/util.rkt
@@ -1,6 +1,6 @@
 #lang racket
 
-(require "grammar.ss"
+(require "grammar.rkt"
          redex/reduction-semantics)
 
 (provide (all-defined-out))
diff --git a/collects/redex/examples/racket-machine/verification-test.rkt b/collects/redex/examples/racket-machine/verification-test.rkt
index 5f79e5bfb7..ebabc33d81 100644
--- a/collects/redex/examples/racket-machine/verification-test.rkt
+++ b/collects/redex/examples/racket-machine/verification-test.rkt
@@ -1,7 +1,7 @@
 #lang racket
 
 (require redex/reduction-semantics)
-(require "grammar.ss" "verification.ss")
+(require "grammar.rkt" "verification.rkt")
 
 ;; localrefs
 (test-predicate
diff --git a/collects/redex/examples/racket-machine/verification.rkt b/collects/redex/examples/racket-machine/verification.rkt
index b6b305bd53..b852d96156 100644
--- a/collects/redex/examples/racket-machine/verification.rkt
+++ b/collects/redex/examples/racket-machine/verification.rkt
@@ -1,7 +1,7 @@
 #lang racket
 
 (require redex/reduction-semantics)
-(require "grammar.ss" "util.ss")
+(require "grammar.rkt" "util.rkt")
 
 (define (bytecode-ok? e)
   (not (eq? 'invalid (car (term (verify ,e () 0 #f () () ∅))))))
diff --git a/collects/redex/examples/types.rkt b/collects/redex/examples/types.rkt
index d3e1548ccf..9bbac06a7a 100644
--- a/collects/redex/examples/types.rkt
+++ b/collects/redex/examples/types.rkt
@@ -1,6 +1,6 @@
 #lang racket
 (require redex
-         "subst.ss")
+         "subst.rkt")
 
 (reduction-steps-cutoff 10)
 
diff --git a/collects/redex/gui.rkt b/collects/redex/gui.rkt
index 93b18b66a4..e30e919a4c 100644
--- a/collects/redex/gui.rkt
+++ b/collects/redex/gui.rkt
@@ -4,11 +4,11 @@
 
 #lang racket/base
 
-(require "private/stepper.ss"
-         "private/traces.ss"
-         "private/matcher.ss"
-         "private/reduction-semantics.ss"
-         "private/size-snip.ss"
+(require "private/stepper.rkt"
+         "private/traces.rkt"
+         "private/matcher.rkt"
+         "private/reduction-semantics.rkt"
+         "private/size-snip.rkt"
          mrlib/graph
          racket/contract
          racket/class
diff --git a/collects/redex/main.rkt b/collects/redex/main.rkt
index 9bfc2679f5..56abe68f18 100644
--- a/collects/redex/main.rkt
+++ b/collects/redex/main.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
-(require "reduction-semantics.ss"
-         "gui.ss"
-         "pict.ss")
-(provide (all-from-out "reduction-semantics.ss"
-                       "gui.ss" 
-                       "pict.ss"))
+(require "reduction-semantics.rkt"
+         "gui.rkt"
+         "pict.rkt")
+(provide (all-from-out "reduction-semantics.rkt"
+                       "gui.rkt"
+                       "pict.rkt"))
diff --git a/collects/redex/pict.rkt b/collects/redex/pict.rkt
index 9a749ff7ab..abb27d9d18 100644
--- a/collects/redex/pict.rkt
+++ b/collects/redex/pict.rkt
@@ -1,11 +1,11 @@
 #lang racket/base
 
 (require racket/contract
-         "private/pict.ss"
-         "private/core-layout.ss"
-         "private/loc-wrapper.ss"
-         "reduction-semantics.ss"
-         (lib "mrpict.ss" "texpict"))
+         "private/pict.rkt"
+         "private/core-layout.rkt"
+         "private/loc-wrapper.rkt"
+         "reduction-semantics.rkt"
+         texpict/mrpict)
 
 (define reduction-rule-style/c
   (symbols 'compact-vertical
diff --git a/collects/redex/private/compiler/redextomatrix.rkt b/collects/redex/private/compiler/redextomatrix.rkt
index 7277c26b86..dd1a2deac5 100644
--- a/collects/redex/private/compiler/redextomatrix.rkt
+++ b/collects/redex/private/compiler/redextomatrix.rkt
@@ -10,7 +10,7 @@
                   build-flat-context
                   the-hole
                   )
-         (lib "list.ss"))
+         racket/list)
 
 (define plug (λ (x y)
                (cond 
diff --git a/collects/redex/private/core-layout.rkt b/collects/redex/private/core-layout.rkt
index aea32a84fe..8b0f8d3ec3 100644
--- a/collects/redex/private/core-layout.rkt
+++ b/collects/redex/private/core-layout.rkt
@@ -1,8 +1,8 @@
 #lang scheme/base
 
-(require "loc-wrapper.ss"
-         "matcher.ss"
-         "reduction-semantics.ss"
+(require "loc-wrapper.rkt"
+         "matcher.rkt"
+         "reduction-semantics.rkt"
          
          texpict/utils
          texpict/mrpict
@@ -120,7 +120,7 @@
   (define-struct token (column span) #:inspector (make-inspector))
   
   ;; string : string
-  ;; style : valid third argument to mrpict.ss's `text' function
+  ;; style : valid third argument to mrpict.rkt's `text' function
   (define-struct (string-token token) (string style) #:inspector (make-inspector))
   
   ;; width : number
diff --git a/collects/redex/private/loc-wrapper-ct.rkt b/collects/redex/private/loc-wrapper-ct.rkt
index 51f28aae05..08c1a0245e 100644
--- a/collects/redex/private/loc-wrapper-ct.rkt
+++ b/collects/redex/private/loc-wrapper-ct.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 (require (for-template scheme/base)
-         (for-template "loc-wrapper-rt.ss")
-         "term-fn.ss")
+         (for-template "loc-wrapper-rt.rkt")
+         "term-fn.rkt")
 (provide to-lw/proc to-lw/uq/proc is-term-fn?)
 
 ;; this parameter allows define-metafunction to
diff --git a/collects/redex/private/loc-wrapper-rt.rkt b/collects/redex/private/loc-wrapper-rt.rkt
index f71b702764..e3f285e9a9 100644
--- a/collects/redex/private/loc-wrapper-rt.rkt
+++ b/collects/redex/private/loc-wrapper-rt.rkt
@@ -1,12 +1,12 @@
 #lang scheme/base
 
-;; this is the runtime code for loc-wrapper-ct.ss.
+;; this is the runtime code for loc-wrapper-ct.rkt.
 ;; it isn't really its own module, but separated
 ;; out in order to get the phases right.
 (provide (all-defined-out))
 
-(require (lib "etc.ss")
-         "term.ss")
+(require mzlib/etc
+         "term.rkt")
 
 (define (init-loc-wrapper e line column quoted?)
   (make-lw e line #f column #f (not quoted?) #f))
diff --git a/collects/redex/private/loc-wrapper.rkt b/collects/redex/private/loc-wrapper.rkt
index ac409abe47..7651dc5c6e 100644
--- a/collects/redex/private/loc-wrapper.rkt
+++ b/collects/redex/private/loc-wrapper.rkt
@@ -2,8 +2,8 @@
 
 (require scheme/contract
          (for-syntax scheme/base)
-         (for-syntax "loc-wrapper-ct.ss")
-         "loc-wrapper-rt.ss")
+         (for-syntax "loc-wrapper-ct.rkt")
+         "loc-wrapper-rt.rkt")
 
 (define-syntax (to-lw stx) 
   (syntax-case stx ()
diff --git a/collects/redex/private/matcher.rkt b/collects/redex/private/matcher.rkt
index 87c4ae1472..1470e8719c 100644
--- a/collects/redex/private/matcher.rkt
+++ b/collects/redex/private/matcher.rkt
@@ -14,7 +14,7 @@ before the pattern compiler is invoked.
 (require scheme/list
          scheme/match
          scheme/contract
-         "underscore-allowed.ss")
+         "underscore-allowed.rkt")
 
 (define-struct compiled-pattern (cp))
 
@@ -103,7 +103,7 @@ before the pattern compiler is invoked.
              (bind-exp rib)
              (loop (cdr ribs))))])))
 
-;; compile-language : language-pict-info[see pict.ss] (listof nt) (listof (listof sym)) -> compiled-lang
+;; compile-language : language-pict-info[see pict.rkt] (listof nt) (listof (listof sym)) -> compiled-lang
 (define (compile-language pict-info lang nt-map)
   (let* ([clang-ht (make-hasheq)]
          [clang-list-ht (make-hasheq)]
@@ -1150,7 +1150,7 @@ before the pattern compiler is invoked.
                        [hole-exp (mtch-hole mtch)]
                        [contractum-mtches (match-contractum hole-exp old-hole-info)])
                   (when (eq? none hole-exp)
-                    (error 'matcher.ss "found zero holes when matching a decomposition"))
+                    (error 'matcher.rkt "found zero holes when matching a decomposition"))
                   (if contractum-mtches
                       (let i-loop ([contractum-mtches contractum-mtches]
                                    [acc acc])
@@ -1318,7 +1318,7 @@ before the pattern compiler is invoked.
   (cond
     [(eq? none s1) s2]
     [(eq? none s2) s1]
-    [(error 'matcher.ss "found two holes")]))
+    [(error 'matcher.rkt "found two holes")]))
 
 ;; reverse-multiples : (listof mtch[to-lists]) -> (listof mtch[to-lists])
 ;; reverses the rhs of each rib in the bindings and reverses the context.
diff --git a/collects/redex/private/pict.rkt b/collects/redex/private/pict.rkt
index 3e061ce4d7..0efb8b15e1 100644
--- a/collects/redex/private/pict.rkt
+++ b/collects/redex/private/pict.rkt
@@ -8,7 +8,7 @@
          texpict/mrpict
          texpict/utils
          
-         "reduction-semantics.ss"
+         "reduction-semantics.rkt"
          "struct.rkt"
          "loc-wrapper.rkt"
          "matcher.rkt"
@@ -934,7 +934,7 @@
                     (list*
                      ;; the first loc wrapper is just there to make the
                      ;; shape of this line be one that the apply-rewrites
-                     ;; function (in core-layout.ss) recognizes as a metafunction
+                     ;; function (in core-layout.rkt) recognizes as a metafunction
                      (make-lw "("
                               (lw-line an-lw)
                               0
diff --git a/collects/redex/private/reduction-semantics.rkt b/collects/redex/private/reduction-semantics.rkt
index 771b331e9b..a7a4e779e8 100644
--- a/collects/redex/private/reduction-semantics.rkt
+++ b/collects/redex/private/reduction-semantics.rkt
@@ -1,22 +1,22 @@
 #lang racket/base
 
-(require "matcher.ss"
-         "struct.ss"
-         "term.ss"
-         "fresh.ss"
-         "loc-wrapper.ss"
-	 "error.ss"
+(require "matcher.rkt"
+         "struct.rkt"
+         "term.rkt"
+         "fresh.rkt"
+         "loc-wrapper.rkt"
+         "error.rkt"
          racket/trace
          racket/contract
          racket/list
-         (lib "etc.ss"))
+         mzlib/etc)
 
-(require (for-syntax (lib "name.ss" "syntax")
-                     "loc-wrapper-ct.ss"
-                     "rewrite-side-conditions.ss"
-                     "term-fn.ss"
-                     "underscore-allowed.ss"
-                     (lib "boundmap.ss" "syntax")
+(require (for-syntax syntax/name
+                     "loc-wrapper-ct.rkt"
+                     "rewrite-side-conditions.rkt"
+                     "term-fn.rkt"
+                     "underscore-allowed.rkt"
+                     syntax/boundmap
                      scheme/base
                      (prefix-in pattern- scheme/match)
                      syntax/parse
diff --git a/collects/redex/private/rewrite-side-conditions.rkt b/collects/redex/private/rewrite-side-conditions.rkt
index 6adf0b6f0f..74d6e73b9a 100644
--- a/collects/redex/private/rewrite-side-conditions.rkt
+++ b/collects/redex/private/rewrite-side-conditions.rkt
@@ -1,10 +1,10 @@
 (module rewrite-side-conditions scheme
-  (require (lib "list.ss")
-           "underscore-allowed.ss")
+  (require mzlib/list
+           "underscore-allowed.rkt")
   (require (for-template
             mzscheme
-            "term.ss"
-            "matcher.ss"))
+            "term.rkt"
+            "matcher.rkt"))
   
   (provide rewrite-side-conditions/check-errs
            extract-names
diff --git a/collects/redex/private/rg.rkt b/collects/redex/private/rg.rkt
index d9a736a2dc..8b6a81579c 100644
--- a/collects/redex/private/rg.rkt
+++ b/collects/redex/private/rg.rkt
@@ -1,15 +1,15 @@
 #lang scheme
 
-(require "matcher.ss"
-         "reduction-semantics.ss"
-         "underscore-allowed.ss"
-         "term.ss"
-         "error.ss"
-         "struct.ss"
-         (for-syntax "rewrite-side-conditions.ss")
-         (for-syntax "term-fn.ss")
-         (for-syntax "reduction-semantics.ss")
-         (for-syntax "keyword-macros.ss")
+(require "matcher.rkt"
+         "reduction-semantics.rkt"
+         "underscore-allowed.rkt"
+         "term.rkt"
+         "error.rkt"
+         "struct.rkt"
+         (for-syntax "rewrite-side-conditions.rkt")
+         (for-syntax "term-fn.rkt")
+         (for-syntax "reduction-semantics.rkt")
+         (for-syntax "keyword-macros.rkt")
          mrlib/tex-table)
 
 (define redex-pseudo-random-generator
diff --git a/collects/redex/private/size-snip.rkt b/collects/redex/private/size-snip.rkt
index b146b0760c..5ca26fd130 100644
--- a/collects/redex/private/size-snip.rkt
+++ b/collects/redex/private/size-snip.rkt
@@ -3,7 +3,7 @@
          scheme/class
          framework
          scheme/pretty
-         "matcher.ss")
+         "matcher.rkt")
 
 (provide reflowing-snip<%>
          size-editor-snip%
diff --git a/collects/redex/private/stepper.rkt b/collects/redex/private/stepper.rkt
index 67471bc03b..340490064e 100644
--- a/collects/redex/private/stepper.rkt
+++ b/collects/redex/private/stepper.rkt
@@ -21,9 +21,9 @@ todo:
          framework
          mrlib/graph
          racket/contract
-         "sexp-diffs.ss"
-         "size-snip.ss"
-         "reduction-semantics.ss")
+         "sexp-diffs.rkt"
+         "size-snip.rkt"
+         "reduction-semantics.rkt")
   
   (provide stepper stepper/seed
            
diff --git a/collects/redex/private/struct.rkt b/collects/redex/private/struct.rkt
index 8e6fa5c7bb..e96d8da7c1 100644
--- a/collects/redex/private/struct.rkt
+++ b/collects/redex/private/struct.rkt
@@ -1,6 +1,6 @@
 #lang racket
 
-(require "matcher.ss")
+(require "matcher.rkt")
 
 ;; don't provide reduction-relation directly, so that we can use that for the macro's name.
 (provide reduction-relation-lang
diff --git a/collects/redex/private/term.rkt b/collects/redex/private/term.rkt
index f2bf65f772..0ce68d3e26 100644
--- a/collects/redex/private/term.rkt
+++ b/collects/redex/private/term.rkt
@@ -1,11 +1,11 @@
 #lang scheme/base
 
 (require (for-syntax scheme/base 
-                     "term-fn.ss"
+                     "term-fn.rkt"
                      syntax/boundmap
                      racket/syntax)
          "error.rkt"
-         "matcher.ss")
+         "matcher.rkt")
 
 (provide term term-let term-let/error-name term-let-fn term-define-fn hole in-hole)
 
diff --git a/collects/redex/private/traces.rkt b/collects/redex/private/traces.rkt
index a6ce716691..6d7a4ce1eb 100644
--- a/collects/redex/private/traces.rkt
+++ b/collects/redex/private/traces.rkt
@@ -5,10 +5,10 @@
 ;; equal hash-table
 
 (require mrlib/graph
-         "reduction-semantics.ss"
-         "matcher.ss"
-         "size-snip.ss"
-         "dot.ss"
+         "reduction-semantics.rkt"
+         "matcher.rkt"
+         "size-snip.rkt"
+         "dot.rkt"
          racket/gui/base
          racket/class
          racket/file
diff --git a/collects/redex/reduction-semantics.rkt b/collects/redex/reduction-semantics.rkt
index e2989116be..4e5fce2685 100644
--- a/collects/redex/reduction-semantics.rkt
+++ b/collects/redex/reduction-semantics.rkt
@@ -1,13 +1,13 @@
 #lang scheme/base
 (require scheme/contract)
 
-(require "private/reduction-semantics.ss"
-         "private/matcher.ss"
-         "private/term.ss"
-         "private/rg.ss"
-         "private/error.ss")
+(require "private/reduction-semantics.rkt"
+         "private/matcher.rkt"
+         "private/term.rkt"
+         "private/rg.rkt"
+         "private/error.rkt")
 
-(provide exn:fail:redex?) ;; from error.ss
+(provide exn:fail:redex?) ;; from error.rkt
 
 (provide reduction-relation 
          --> fresh with ;; keywords for reduction-relation
diff --git a/collects/redex/tests/bitmap-test-util.rkt b/collects/redex/tests/bitmap-test-util.rkt
index f717586c9b..e394a37249 100644
--- a/collects/redex/tests/bitmap-test-util.rkt
+++ b/collects/redex/tests/bitmap-test-util.rkt
@@ -1,8 +1,8 @@
 #lang scheme/gui
 (require framework
          slideshow/pict
-         "../pict.ss"
-         "../reduction-semantics.ss")
+         "../pict.rkt"
+         "../reduction-semantics.rkt")
 
 (provide test done)
 
@@ -125,7 +125,7 @@
      test-result-single-panel]
     [else
      (let ()
-       (define f (new frame% [label "bitmap-test.ss failures"]))
+       (define f (new frame% [label "bitmap-test.rkt failures"]))
        (define lined (new vertical-panel% [parent f] [style '(border)]))
        (define sp (new panel:single% [parent lined]))
        (define current-index 0)
diff --git a/collects/redex/tests/bitmap-test.rkt b/collects/redex/tests/bitmap-test.rkt
index e231d693e4..7d917ff198 100644
--- a/collects/redex/tests/bitmap-test.rkt
+++ b/collects/redex/tests/bitmap-test.rkt
@@ -1,6 +1,6 @@
 #lang scheme
-(require "bitmap-test-util.ss"
-         "../main.ss")
+(require "bitmap-test-util.rkt"
+         "../main.rkt")
 
 ;; tests: 
 ;;  - language,
@@ -257,5 +257,5 @@
      (r x)])
   (test (render-relation r) "relation-with-name.png"))    
 
-(printf "bitmap-test.ss: ")
+(printf "bitmap-test.rkt: ")
 (done)
diff --git a/collects/redex/tests/color-test.rkt b/collects/redex/tests/color-test.rkt
index d13d212756..718c1ec4a6 100644
--- a/collects/redex/tests/color-test.rkt
+++ b/collects/redex/tests/color-test.rkt
@@ -10,8 +10,8 @@ In the other window, you expect to see the currently unreducted terms in green a
 
 #lang scheme/gui
 
-(require "../reduction-semantics.ss"
-         "../gui.ss")
+(require "../reduction-semantics.rkt"
+         "../gui.rkt")
 
 (reduction-steps-cutoff 1)
 
diff --git a/collects/redex/tests/compiler/redex-tests.rkt b/collects/redex/tests/compiler/redex-tests.rkt
index d435915b90..e4c7f2ebd7 100644
--- a/collects/redex/tests/compiler/redex-tests.rkt
+++ b/collects/redex/tests/compiler/redex-tests.rkt
@@ -1,8 +1,8 @@
 #lang racket
 (require (only-in redex term))
-(require  "../../private/matcher.ss"
-          (only-in "../test-util.ss" equal/bindings?)
-          (lib "list.ss"))
+(require "../../private/matcher.rkt"
+         (only-in "../test-util.rkt" equal/bindings?)
+         mzlib/list)
 (require "../../private/compiler/match.rkt")
 (require "../../private/compiler/redextomatrix.rkt")
 
diff --git a/collects/redex/tests/core-layout-test.rkt b/collects/redex/tests/core-layout-test.rkt
index a184bc77c1..62de26f24d 100644
--- a/collects/redex/tests/core-layout-test.rkt
+++ b/collects/redex/tests/core-layout-test.rkt
@@ -1,14 +1,12 @@
 #lang scheme/base
 
-(require "../private/core-layout.ss"
-         "../private/loc-wrapper.ss"
-         "lw-test-util.ss"
-         "test-util.ss"
-         (lib "struct.ss"))
+(require "../private/core-layout.rkt"
+         "../private/loc-wrapper.rkt"
+         "lw-test-util.rkt"
+         "test-util.rkt"
+         mzlib/struct)
 
-(require (lib "mrpict.ss" "texpict")
-         (lib "mred.ss" "mred")
-         (lib "class.ss"))
+(require texpict/mrpict mred/mred mzlib/class)
 (dc-for-text-size (make-object bitmap-dc% (make-object bitmap% 1 1)))
 
 (reset-count)
@@ -79,4 +77,4 @@
                              (make-pict-token 0 1 'pict)
                              (make-pict-token 1 0 'pict)))))
 
-(print-tests-passed "core-layout.ss")
+(print-tests-passed "core-layout.rkt")
diff --git a/collects/redex/tests/keyword-macros-test.rkt b/collects/redex/tests/keyword-macros-test.rkt
index b2109022f3..21a2ae9b83 100644
--- a/collects/redex/tests/keyword-macros-test.rkt
+++ b/collects/redex/tests/keyword-macros-test.rkt
@@ -1,7 +1,7 @@
 #lang scheme
 
-(require "../private/keyword-macros.ss"
-         "test-util.ss")
+(require "../private/keyword-macros.rkt"
+         "test-util.rkt")
 
 (reset-count)
 
@@ -62,4 +62,4 @@
    #:blaming (format "~a" form)
    #:message "#:a arg"))
 
-(print-tests-passed 'keyword-macros-test.ss)
+(print-tests-passed 'keyword-macros-test.rkt)
diff --git a/collects/redex/tests/lw-test-util.rkt b/collects/redex/tests/lw-test-util.rkt
index a1dd92c934..350ddf5e72 100644
--- a/collects/redex/tests/lw-test-util.rkt
+++ b/collects/redex/tests/lw-test-util.rkt
@@ -1,5 +1,5 @@
 (module lw-test-util mzscheme
-  (require "../private/loc-wrapper.ss")
+  (require "../private/loc-wrapper.rkt")
   (provide normalize-lw)
   
   (define (normalize-lw lw)
diff --git a/collects/redex/tests/lw-test.rkt b/collects/redex/tests/lw-test.rkt
index 0025412035..1cc6bc67d2 100644
--- a/collects/redex/tests/lw-test.rkt
+++ b/collects/redex/tests/lw-test.rkt
@@ -50,9 +50,9 @@
 
 
 (module lw-test racket/base
-  (require "test-util.ss"
-           "../private/loc-wrapper.ss"
-           "lw-test-util.ss"
+  (require "test-util.rkt"
+           "../private/loc-wrapper.rkt"
+           "lw-test-util.rkt"
            (only-in "../pict.rkt" to-lw/stx))
   
   (reset-count)
@@ -322,5 +322,5 @@
     (test (normalize-lw (to-lw/stx (from-str "(a ((b)) c 1 #t)")))
           (normalize-lw (to-lw (a ((b)) c 1 #t)))))
   
-  (print-tests-passed "lw-test.ss"))
+  (print-tests-passed "lw-test.rkt"))
 
diff --git a/collects/redex/tests/matcher-test.rkt b/collects/redex/tests/matcher-test.rkt
index 05ec7bf32d..87049b31e7 100644
--- a/collects/redex/tests/matcher-test.rkt
+++ b/collects/redex/tests/matcher-test.rkt
@@ -1,7 +1,7 @@
 (module matcher-test mzscheme
-  (require "../private/matcher.ss"
-           (only "test-util.ss" equal/bindings?)
-           (lib "list.ss"))
+  (require "../private/matcher.rkt"
+           (only "test-util.rkt" equal/bindings?)
+           mzlib/list)
   
   (error-print-width 500)
   
@@ -652,9 +652,9 @@
     
     (cond
       [(= failures 0)
-       (printf "matcher-test.ss: all ~a tests passed.\n" test-count)]
+       (printf "matcher-test.rkt: all ~a tests passed.\n" test-count)]
       [else
-       (printf "matcher-test.ss: ~a test~a failed.\n" 
+       (printf "matcher-test.rkt: ~a test~a failed.\n" 
                failures
                (if (= failures 1)
                    ""
diff --git a/collects/redex/tests/pict-test.rkt b/collects/redex/tests/pict-test.rkt
index c80da26ac0..f28c65bc0b 100644
--- a/collects/redex/tests/pict-test.rkt
+++ b/collects/redex/tests/pict-test.rkt
@@ -2,14 +2,12 @@
   ;; these tests just make sure that errors don't
   ;; happen. These tests are really only last resorts
   ;; for testing functions that aren't easily extraced
-  ;; from the pict.ss library
+  ;; from the pict.rkt library
   
-  (require "../reduction-semantics.ss"
-           "../pict.ss")
+  (require "../reduction-semantics.rkt"
+           "../pict.rkt")
   
-  (require (lib "mrpict.ss" "texpict")
-           (lib "mred.ss" "mred")
-           (lib "class.ss"))
+  (require texpict/mrpict mred/mred mzlib/class)
   
   (define-language empty-language)
   
@@ -50,4 +48,4 @@
   
   (render-language x0-10)
   
-  (printf "pict-test.ss passed\n"))
+  (printf "pict-test.rkt passed\n"))
diff --git a/collects/redex/tests/rg-test.rkt b/collects/redex/tests/rg-test.rkt
index 4422801cbc..50044f26ca 100644
--- a/collects/redex/tests/rg-test.rkt
+++ b/collects/redex/tests/rg-test.rkt
@@ -1,12 +1,12 @@
 #lang scheme
 
-(require "test-util.ss"
-         "../private/reduction-semantics.ss"
-         "../private/matcher.ss"
-         "../private/term.ss"
-         "../private/rg.ss"
-         "../private/keyword-macros.ss"
-         "../private/error.ss")
+(require "test-util.rkt"
+         "../private/reduction-semantics.rkt"
+         "../private/matcher.rkt"
+         "../private/term.rkt"
+         "../private/rg.rkt"
+         "../private/keyword-macros.rkt"
+         "../private/error.rkt")
 
 (define-namespace-anchor nsa)
 (define ns (namespace-anchor->namespace nsa))
@@ -1340,4 +1340,4 @@
     (test (seed-effect-generate void)
           (seed-effect-generate random))))
 
-(print-tests-passed 'rg-test.ss)
+(print-tests-passed 'rg-test.rkt)
diff --git a/collects/redex/tests/run-tests.rkt b/collects/redex/tests/run-tests.rkt
index 86b7199f98..e960ce43e0 100644
--- a/collects/redex/tests/run-tests.rkt
+++ b/collects/redex/tests/run-tests.rkt
@@ -4,39 +4,39 @@
 (require scheme/runtime-path
          scheme/cmdline
          scheme/match
-         "test-util.ss")
+         "test-util.rkt")
 
 (define test-bitmaps? #t)
 (define test-examples? #f)
 
 (command-line
  #:once-each
- [("--no-bitmaps") "executes bitmap-test.ss" (set! test-bitmaps? #f)]
+ [("--no-bitmaps") "executes bitmap-test.rkt" (set! test-bitmaps? #f)]
  [("--examples") "executes the tests in the examples directory" (set! test-examples? #t)])
 
 (define test-files
   (append
-   '("lw-test.ss" 
-     "matcher-test.ss" 
-     "tl-test.ss" 
-     "term-test.ss" 
-     "rg-test.ss" 
-     "keyword-macros-test.ss"
-     "core-layout-test.ss" 
-     "pict-test.ss"
-     "hole-test.ss"
-     "stepper-test.ss"
+   '("lw-test.rkt"
+     "matcher-test.rkt"
+     "tl-test.rkt"
+     "term-test.rkt"
+     "rg-test.rkt"
+     "keyword-macros-test.rkt"
+     "core-layout-test.rkt"
+     "pict-test.rkt"
+     "hole-test.rkt"
+     "stepper-test.rkt"
      "test-docs-complete.rkt")
-   (if test-bitmaps? '("bitmap-test.ss") '())
-   (if test-examples? 
+   (if test-bitmaps? '("bitmap-test.rkt") '())
+   (if test-examples?
        '("../examples/stlc.rkt"
-         "../examples/pi-calculus.ss"
-         ("../examples/beginner.ss" main)
-         "../examples/racket-machine/reduction-test.ss"
-         "../examples/racket-machine/verification-test.ss"
+         "../examples/pi-calculus.rkt"
+         ("../examples/beginner.rkt" main)
+         "../examples/racket-machine/reduction-test.rkt"
+         "../examples/racket-machine/verification-test.rkt"
          "../examples/delim-cont/test.rkt"
          "../examples/cont-mark-transform/all-test.rkt"
-         ("../examples/r6rs/r6rs-tests.ss" main))
+         ("../examples/r6rs/r6rs-tests.rkt" main))
        '())))
 
 (define-runtime-path here ".")
@@ -63,5 +63,5 @@
      (flush)))
  test-files)
 
-(printf "\nWARNING: didn't run color-test.ss\n")
+(printf "\nWARNING: didn't run color-test.rkt\n")
 (flush)
diff --git a/collects/redex/tests/stepper-test.rkt b/collects/redex/tests/stepper-test.rkt
index d558282fac..c62bf6a58f 100644
--- a/collects/redex/tests/stepper-test.rkt
+++ b/collects/redex/tests/stepper-test.rkt
@@ -45,4 +45,4 @@
 (test (diff (term |a'|) (term b))
       (cons (list (cons 0 4)) (list (cons 0 1))))
 
-(print-tests-passed 'stepper-test.ss)
+(print-tests-passed 'stepper-test.rkt)
diff --git a/collects/redex/tests/term-test.rkt b/collects/redex/tests/term-test.rkt
index cc51a96300..8aafb83614 100644
--- a/collects/redex/tests/term-test.rkt
+++ b/collects/redex/tests/term-test.rkt
@@ -1,7 +1,7 @@
 (module term-test scheme
-  (require "../private/term.ss"
-           "../private/matcher.ss"
-           "test-util.ss")
+  (require "../private/term.rkt"
+           "../private/matcher.rkt"
+           "test-util.rkt")
   
   (reset-count)
   (test (term 1) 1)
@@ -180,4 +180,4 @@
             (gensym 'wrong)))
         'label)
   
-  (print-tests-passed 'term-test.ss))
+  (print-tests-passed 'term-test.rkt))
diff --git a/collects/redex/tests/test-util.rkt b/collects/redex/tests/test-util.rkt
index 9d06e5a9e7..70345d86fa 100644
--- a/collects/redex/tests/test-util.rkt
+++ b/collects/redex/tests/test-util.rkt
@@ -1,6 +1,6 @@
 #lang scheme
 
-(require "../private/matcher.ss"
+(require "../private/matcher.rkt"
          (for-syntax syntax/parse)
          errortrace/errortrace-lib
          errortrace/errortrace-key)
diff --git a/collects/redex/tests/tl-test.rkt b/collects/redex/tests/tl-test.rkt
index 575d046d31..e9fb9c6ce6 100644
--- a/collects/redex/tests/tl-test.rkt
+++ b/collects/redex/tests/tl-test.rkt
@@ -1,9 +1,9 @@
 #lang racket/gui
-  (require "../reduction-semantics.ss"
-           "test-util.ss"
-           (only-in "../private/matcher.ss" make-bindings make-bind)
+  (require "../reduction-semantics.rkt"
+           "test-util.rkt"
+           (only-in "../private/matcher.rkt" make-bindings make-bind)
            racket/match
-           "../private/struct.ss")
+           "../private/struct.rkt")
   
   (reset-count)
 
@@ -2024,7 +2024,7 @@
           (and m (length m)))
         1)
   
-  (require (lib "list.ss"))
+  (require mzlib/list)
   (let ()
     (define-metafunction lc-lang
       free-vars : e -> (x ...)
@@ -2552,4 +2552,4 @@
      #:blaming "tl-test"
      #:message "steps expression"))
   
-  (print-tests-passed 'tl-test.ss)
+  (print-tests-passed 'tl-test.rkt)
diff --git a/collects/repo-time-stamp/info.rkt b/collects/repo-time-stamp/info.rkt
index c012efd755..1166375434 100644
--- a/collects/repo-time-stamp/info.rkt
+++ b/collects/repo-time-stamp/info.rkt
@@ -1,4 +1,4 @@
 #lang setup/infotab
 
-(define tools (list "time-stamp.ss"))
+(define tools (list "time-stamp.rkt"))
 (define tool-names (list "Repository Time Stamp"))
diff --git a/collects/repo-time-stamp/time-stamp.rkt b/collects/repo-time-stamp/time-stamp.rkt
index 365baafe17..1b87e87d4b 100644
--- a/collects/repo-time-stamp/time-stamp.rkt
+++ b/collects/repo-time-stamp/time-stamp.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-(require drracket/tool racket/unit framework "stamp.ss")
+(require drracket/tool racket/unit framework "stamp.rkt")
 
 (provide tool@)
 (define tool@
diff --git a/collects/scribble/base-render.rkt b/collects/scribble/base-render.rkt
index 0510a27535..8b456965bb 100644
--- a/collects/scribble/base-render.rkt
+++ b/collects/scribble/base-render.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 
-(require "core.ss"
-         "private/render-utils.ss"
+(require "core.rkt"
+         "private/render-utils.rkt"
          mzlib/class
          mzlib/serialize
          scheme/file
@@ -9,7 +9,7 @@
          setup/main-collects
          setup/path-relativize
          file/convertible
-         "render-struct.ss")
+         "render-struct.rkt")
 
 (provide render%)
 
diff --git a/collects/scribble/base.rkt b/collects/scribble/base.rkt
index b11e6d07a6..a563cf999a 100644
--- a/collects/scribble/base.rkt
+++ b/collects/scribble/base.rkt
@@ -1,10 +1,10 @@
 #lang scheme/base
 
-(require "decode.ss"
-         "core.ss"
-         "manual-struct.ss"
-         "decode-struct.ss"
-         "html-properties.ss"
+(require "decode.rkt"
+         "core.rkt"
+         "manual-struct.rkt"
+         "decode-struct.rkt"
+         "html-properties.rkt"
          scheme/list
          scheme/class
          scheme/contract
diff --git a/collects/scribble/base/reader.rkt b/collects/scribble/base/reader.rkt
index a01f5a51a4..11278df862 100644
--- a/collects/scribble/base/reader.rkt
+++ b/collects/scribble/base/reader.rkt
@@ -1,5 +1,5 @@
 #lang scheme/base
-(require (prefix-in scribble: "../reader.ss")
+(require (prefix-in scribble: "../reader.rkt")
          (rename-in syntax/module-reader
                     [#%module-begin #%reader-module-begin]))
 (provide (rename-out [module-begin #%module-begin])
diff --git a/collects/scribble/basic.rkt b/collects/scribble/basic.rkt
index 2bc2252c87..43ccbbc6ff 100644
--- a/collects/scribble/basic.rkt
+++ b/collects/scribble/basic.rkt
@@ -1,8 +1,8 @@
 #lang scheme/base
 
-(require "base.ss"
-         "core.ss"
-         "decode.ss")
+(require "base.rkt"
+         "core.rkt"
+         "decode.rkt")
 
 (provide title
          section
diff --git a/collects/scribble/bnf.rkt b/collects/scribble/bnf.rkt
index 4edf12906a..597dead1a1 100644
--- a/collects/scribble/bnf.rkt
+++ b/collects/scribble/bnf.rkt
@@ -1,7 +1,6 @@
-
 (module bnf mzscheme
-  (require "struct.ss"
-           "decode.ss"
+  (require "struct.rkt"
+           "decode.rkt"
            mzlib/kw
            mzlib/class)
 
diff --git a/collects/scribble/core.rkt b/collects/scribble/core.rkt
index d33689b8a2..84f87e1ffe 100644
--- a/collects/scribble/core.rkt
+++ b/collects/scribble/core.rkt
@@ -1,5 +1,5 @@
 #lang scheme/base
-(require "private/provide-structs.ss"
+(require "private/provide-structs.rkt"
          scheme/serialize
          scheme/contract
          file/convertible)
diff --git a/collects/scribble/decode-struct.rkt b/collects/scribble/decode-struct.rkt
index a9335e8c29..2583e4cb8e 100644
--- a/collects/scribble/decode-struct.rkt
+++ b/collects/scribble/decode-struct.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 
-(require "core.ss"
-         "private/provide-structs.ss")
+(require "core.rkt"
+         "private/provide-structs.rkt")
 
 (provide-structs
  [part-index-desc ()])
diff --git a/collects/scribble/decode.rkt b/collects/scribble/decode.rkt
index a812281e84..2c47e30734 100644
--- a/collects/scribble/decode.rkt
+++ b/collects/scribble/decode.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
-(require "core.ss"
-         "private/provide-structs.ss"
-         "decode-struct.ss"
+(require "core.rkt"
+         "private/provide-structs.rkt"
+         "decode-struct.rkt"
          scheme/contract
          scheme/class
          scheme/list)
diff --git a/collects/scribble/doclang.rkt b/collects/scribble/doclang.rkt
index 298659eba1..3d6ce9b7cd 100644
--- a/collects/scribble/doclang.rkt
+++ b/collects/scribble/doclang.rkt
@@ -1,7 +1,7 @@
 #lang racket/base
 
-(require "struct.ss"
-         "decode.ss"
+(require "struct.rkt"
+         "decode.rkt"
          (for-syntax racket/base
                      syntax/kerncase))
 
diff --git a/collects/scribble/eval.rkt b/collects/scribble/eval.rkt
index 1080c0c842..63f2260258 100644
--- a/collects/scribble/eval.rkt
+++ b/collects/scribble/eval.rkt
@@ -1,6 +1,6 @@
 #lang racket/base
 
-(require "manual.ss" "struct.ss" "scheme.ss" "decode.ss"
+(require "manual.rkt" "struct.rkt" "scheme.rkt" "decode.rkt"
          racket/string racket/list racket/file
          racket/sandbox racket/promise racket/port file/convertible
          (for-syntax racket/base))
diff --git a/collects/scribble/html-properties.rkt b/collects/scribble/html-properties.rkt
index 8621d313d3..ab5da8151d 100644
--- a/collects/scribble/html-properties.rkt
+++ b/collects/scribble/html-properties.rkt
@@ -1,5 +1,5 @@
 #lang scheme/base
-(require "private/provide-structs.ss"
+(require "private/provide-structs.rkt"
          scheme/contract)
 
 (provide-structs
diff --git a/collects/scribble/html-render.rkt b/collects/scribble/html-render.rkt
index c7651bb5b6..0c012ad878 100644
--- a/collects/scribble/html-render.rkt
+++ b/collects/scribble/html-render.rkt
@@ -1,8 +1,8 @@
 #lang scheme/base
 
-(require "core.ss"
-         "private/render-utils.ss"
-         "html-properties.ss"
+(require "core.rkt"
+         "private/render-utils.rkt"
+         "html-properties.rkt"
          scheme/class
          scheme/path
          scheme/file
@@ -19,8 +19,8 @@
          scheme/serialize
          (prefix-in xml: xml/xml)
          (for-syntax scheme/base)
-         "search.ss"
-         (except-in "base.ss" url))
+         "search.rkt"
+         (except-in "base.rkt" url))
 (provide render-mixin
          render-multi-mixin)
 
diff --git a/collects/scribble/info.rkt b/collects/scribble/info.rkt
index d7c2e67a45..07e635daea 100644
--- a/collects/scribble/info.rkt
+++ b/collects/scribble/info.rkt
@@ -1,8 +1,7 @@
 #lang setup/infotab
 
 (define mzscheme-launcher-names '("scribble"))
-(define mzscheme-launcher-libraries '("run.ss"))
-(define compile-omit-paths '("test-reader.ss"))
+(define mzscheme-launcher-libraries '("run.rkt"))
 
 (define raco-commands
   '(("scribble" scribble/run "render a Scribble document" #f)))
diff --git a/collects/scribble/jfp/lang.rkt b/collects/scribble/jfp/lang.rkt
index e5f8f67cf1..460520a261 100644
--- a/collects/scribble/jfp/lang.rkt
+++ b/collects/scribble/jfp/lang.rkt
@@ -4,7 +4,7 @@
          (except-in scribble/base author)
          scribble/decode
          scribble/jfp
-         "../private/defaults.ss"
+         "../private/defaults.rkt"
          (for-syntax scheme/base))
 (provide (except-out (all-from-out scribble/doclang) #%module-begin)
          (all-from-out scribble/jfp)
diff --git a/collects/scribble/latex-properties.rkt b/collects/scribble/latex-properties.rkt
index f500bd7cd6..f03860929e 100644
--- a/collects/scribble/latex-properties.rkt
+++ b/collects/scribble/latex-properties.rkt
@@ -1,5 +1,5 @@
 #lang scheme/base
-(require "private/provide-structs.ss"
+(require "private/provide-structs.rkt"
          scheme/contract)
 
 (provide-structs
diff --git a/collects/scribble/latex-render.rkt b/collects/scribble/latex-render.rkt
index ef470c0b55..56e965f7c6 100644
--- a/collects/scribble/latex-render.rkt
+++ b/collects/scribble/latex-render.rkt
@@ -1,8 +1,8 @@
 #lang scheme/base
 
-(require "core.ss"
-         "latex-properties.ss"
-         "private/render-utils.ss"
+(require "core.rkt"
+         "latex-properties.rkt"
+         "private/render-utils.rkt"
          scheme/class
          scheme/runtime-path
          scheme/port
diff --git a/collects/scribble/lncs/lang.rkt b/collects/scribble/lncs/lang.rkt
index b7d19db34e..ed0f9965fc 100644
--- a/collects/scribble/lncs/lang.rkt
+++ b/collects/scribble/lncs/lang.rkt
@@ -4,7 +4,7 @@
          (except-in scribble/base author)
          (prefix-in s/b: scribble/base)
          scribble/decode
-         "../private/defaults.ss"
+         "../private/defaults.rkt"
          (for-syntax racket/base racket/list)
          setup/main-collects
          scribble/html-properties
diff --git a/collects/scribble/manual-struct.rkt b/collects/scribble/manual-struct.rkt
index 030bd883a3..4496391255 100644
--- a/collects/scribble/manual-struct.rkt
+++ b/collects/scribble/manual-struct.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 
-(require "core.ss"
-         "private/provide-structs.ss"
+(require "core.rkt"
+         "private/provide-structs.rkt"
          scheme/contract)
 
 (provide-structs
diff --git a/collects/scribble/manual.rkt b/collects/scribble/manual.rkt
index 7266ff5163..df113cfa9d 100644
--- a/collects/scribble/manual.rkt
+++ b/collects/scribble/manual.rkt
@@ -1,33 +1,32 @@
 #lang scheme/base
-(require "base.ss"
-         "private/manual-style.ss"
-         "private/manual-scheme.ss"
-         "private/manual-code.ss"
-         "private/manual-mod.ss"
-         "private/manual-tech.ss"
-         "private/manual-bib.ss"
-         "private/manual-proc.ss"
-         "private/manual-form.ss"
-         "private/manual-class.ss"
-         "private/manual-unit.ss"
-         "private/manual-vars.ss"
-         "private/manual-bind.ss")
+(require "base.rkt"
+         "private/manual-style.rkt"
+         "private/manual-scheme.rkt"
+         "private/manual-code.rkt"
+         "private/manual-mod.rkt"
+         "private/manual-tech.rkt"
+         "private/manual-bib.rkt"
+         "private/manual-proc.rkt"
+         "private/manual-form.rkt"
+         "private/manual-class.rkt"
+         "private/manual-unit.rkt"
+         "private/manual-vars.rkt"
+         "private/manual-bind.rkt")
 
 (provide unsyntax
          make-binding-redirect-elements
          defidentifier
-         (all-from-out "base.ss"
-                       "private/manual-style.ss"
-                       "private/manual-scheme.ss"
-                       "private/manual-code.ss"
-                       "private/manual-mod.ss"
-                       "private/manual-tech.ss"
-                       "private/manual-bib.ss"
-                       "private/manual-form.ss"
-                       "private/manual-class.ss"
-                       "private/manual-unit.ss")
-         (except-out (all-from-out "private/manual-vars.ss")
+         (all-from-out "base.rkt"
+                       "private/manual-style.rkt"
+                       "private/manual-scheme.rkt"
+                       "private/manual-code.rkt"
+                       "private/manual-mod.rkt"
+                       "private/manual-tech.rkt"
+                       "private/manual-bib.rkt"
+                       "private/manual-form.rkt"
+                       "private/manual-class.rkt"
+                       "private/manual-unit.rkt")
+         (except-out (all-from-out "private/manual-vars.rkt")
                      *deftogether)
-         (except-out (all-from-out "private/manual-proc.ss")
+         (except-out (all-from-out "private/manual-proc.rkt")
                      *defthing))
-
diff --git a/collects/scribble/manual/lang.rkt b/collects/scribble/manual/lang.rkt
index bebfab3a82..990b784df9 100644
--- a/collects/scribble/manual/lang.rkt
+++ b/collects/scribble/manual/lang.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 (require scribble/doclang 
          scribble/manual
-         "../private/defaults.ss")
+         "../private/defaults.rkt")
 (provide (except-out (all-from-out scribble/doclang) #%module-begin)
          (all-from-out scribble/manual)
          (rename-out [module-begin #%module-begin]))
diff --git a/collects/scribble/pdf-render.rkt b/collects/scribble/pdf-render.rkt
index e83e6be823..2bd5574b2d 100644
--- a/collects/scribble/pdf-render.rkt
+++ b/collects/scribble/pdf-render.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 
-(require "private/indirect-renderer.ss" "private/run-pdflatex.ss"
-         (prefix-in latex: "latex-render.ss"))
+(require "private/indirect-renderer.rkt" "private/run-pdflatex.rkt"
+         (prefix-in latex: "latex-render.rkt"))
 
 (provide render-mixin)
 
diff --git a/collects/scribble/private/manual-bib.rkt b/collects/scribble/private/manual-bib.rkt
index d00e1b1ec2..afc155ce90 100644
--- a/collects/scribble/private/manual-bib.rkt
+++ b/collects/scribble/private/manual-bib.rkt
@@ -1,13 +1,13 @@
 #lang scheme/base
 (require scheme/contract
-         "../decode.ss"
-         "../struct.ss"
-         "../basic.ss"
-         "on-demand.ss"
-         (only-in "../core.ss" make-style)
-         "manual-sprop.ss"
-         "manual-utils.ss"
-         "manual-style.ss")
+         "../decode.rkt"
+         "../struct.rkt"
+         "../basic.rkt"
+         "on-demand.rkt"
+         (only-in "../core.rkt" make-style)
+         "manual-sprop.rkt"
+         "manual-utils.rkt"
+         "manual-style.rkt")
 
 (define-struct a-bib-entry (key val))
 
diff --git a/collects/scribble/private/manual-bind.rkt b/collects/scribble/private/manual-bind.rkt
index 8b13cd262a..7acf507c06 100644
--- a/collects/scribble/private/manual-bind.rkt
+++ b/collects/scribble/private/manual-bind.rkt
@@ -1,11 +1,11 @@
 #lang scheme/base
-(require "../decode.ss"
-         "../struct.ss"
-         "../scheme.ss"
-         "../search.ss"
-         "../basic.ss"
-         "../manual-struct.ss"
-         "manual-ex.ss"
+(require "../decode.rkt"
+         "../struct.rkt"
+         "../scheme.rkt"
+         "../search.rkt"
+         "../basic.rkt"
+         "../manual-struct.rkt"
+         "manual-ex.rkt"
          scheme/string
          scheme/contract
          scheme/list
diff --git a/collects/scribble/private/manual-class.rkt b/collects/scribble/private/manual-class.rkt
index 8423a1f556..7c55292a9b 100644
--- a/collects/scribble/private/manual-class.rkt
+++ b/collects/scribble/private/manual-class.rkt
@@ -1,21 +1,21 @@
 #lang scheme/base
-(require "../decode.ss"
-         "../struct.ss"
-         "../scheme.ss"
-         "../search.ss"
-         "../basic.ss"
-         "../manual-struct.ss"
-         "qsloc.ss"
+(require "../decode.rkt"
+         "../struct.rkt"
+         "../scheme.rkt"
+         "../search.rkt"
+         "../basic.rkt"
+         "../manual-struct.rkt"
+         "qsloc.rkt"
          scheme/serialize
          scheme/stxparam
-         "manual-utils.ss"
-         "manual-vars.ss"
-         "manual-style.ss"
-         "manual-scheme.ss"
-         "manual-bind.ss"
-         "manual-method.ss"
-         "manual-proc.ss"
-         "manual-ex.ss"
+         "manual-utils.rkt"
+         "manual-vars.rkt"
+         "manual-style.rkt"
+         "manual-scheme.rkt"
+         "manual-bind.rkt"
+         "manual-method.rkt"
+         "manual-proc.rkt"
+         "manual-ex.rkt"
          scheme/string
          scheme/list
          (for-syntax scheme/base)
diff --git a/collects/scribble/private/manual-ex.rkt b/collects/scribble/private/manual-ex.rkt
index 01a0c5b0bc..003f7ee494 100644
--- a/collects/scribble/private/manual-ex.rkt
+++ b/collects/scribble/private/manual-ex.rkt
@@ -1,5 +1,5 @@
 #lang scheme/base
-(require "../struct.ss")
+(require "../struct.rkt")
 
 ; XXX unknown contracts
 (provide (struct-out exporting-libraries)
diff --git a/collects/scribble/private/manual-form.rkt b/collects/scribble/private/manual-form.rkt
index 5a03d100f5..7d98050dfe 100644
--- a/collects/scribble/private/manual-form.rkt
+++ b/collects/scribble/private/manual-form.rkt
@@ -1,18 +1,18 @@
 #lang scheme/base
-(require "../decode.ss"
-         "../struct.ss"
-         "../scheme.ss"
-         "../search.ss"
-         "../basic.ss"
-         "../manual-struct.ss"
-         "qsloc.ss"
-         "manual-utils.ss"
-         "manual-vars.ss"
-         "manual-style.ss"
-         "manual-scheme.ss"
-         "manual-bind.ss"
-         "manual-method.ss"
-         "manual-ex.ss"
+(require "../decode.rkt"
+         "../struct.rkt"
+         "../scheme.rkt"
+         "../search.rkt"
+         "../basic.rkt"
+         "../manual-struct.rkt"
+         "qsloc.rkt"
+         "manual-utils.rkt"
+         "manual-vars.rkt"
+         "manual-style.rkt"
+         "manual-scheme.rkt"
+         "manual-bind.rkt"
+         "manual-method.rkt"
+         "manual-ex.rkt"
          scheme/string
          scheme/list
          (for-syntax scheme/base)
diff --git a/collects/scribble/private/manual-method.rkt b/collects/scribble/private/manual-method.rkt
index a72be88a06..ab095ce349 100644
--- a/collects/scribble/private/manual-method.rkt
+++ b/collects/scribble/private/manual-method.rkt
@@ -1,9 +1,9 @@
 #lang scheme/base
-(require "../struct.ss"
-         "../search.ss"
-         "../scheme.ss"
-         "../basic.ss"
-         "manual-scheme.ss"
+(require "../struct.rkt"
+         "../search.rkt"
+         "../scheme.rkt"
+         "../basic.rkt"
+         "manual-scheme.rkt"
          (for-syntax scheme/base))
 
 (provide ;; public:
diff --git a/collects/scribble/private/manual-mod.rkt b/collects/scribble/private/manual-mod.rkt
index bcae6287be..6cd96aecec 100644
--- a/collects/scribble/private/manual-mod.rkt
+++ b/collects/scribble/private/manual-mod.rkt
@@ -1,11 +1,11 @@
 #lang scheme/base
-(require "../decode.ss"
-         "../struct.ss"
-         "../basic.ss"
-         "../manual-struct.ss"
-         "manual-ex.ss"
-         "manual-style.ss"
-         "manual-scheme.ss"
+(require "../decode.rkt"
+         "../struct.rkt"
+         "../basic.rkt"
+         "../manual-struct.rkt"
+         "manual-ex.rkt"
+         "manual-style.rkt"
+         "manual-scheme.rkt"
          scheme/string
          scheme/list
          (for-syntax scheme/base)
diff --git a/collects/scribble/private/manual-proc.rkt b/collects/scribble/private/manual-proc.rkt
index 8ed3c3e045..5c7d340f3f 100644
--- a/collects/scribble/private/manual-proc.rkt
+++ b/collects/scribble/private/manual-proc.rkt
@@ -1,19 +1,19 @@
 #lang racket/base
-(require "../decode.ss"
-         "../struct.ss"
-         "../scheme.ss"
-         "../search.ss"
-         "../basic.ss"
-         "../manual-struct.ss"
-         "qsloc.ss"
-         "manual-utils.ss"
-         "manual-vars.ss"
-         "manual-style.ss"
-         "manual-scheme.ss"
-         "manual-bind.ss"
-         "manual-method.ss"
-         "manual-ex.ss"
-         "on-demand.ss"
+(require "../decode.rkt"
+         "../struct.rkt"
+         "../scheme.rkt"
+         "../search.rkt"
+         "../basic.rkt"
+         "../manual-struct.rkt"
+         "qsloc.rkt"
+         "manual-utils.rkt"
+         "manual-vars.rkt"
+         "manual-style.rkt"
+         "manual-scheme.rkt"
+         "manual-bind.rkt"
+         "manual-method.rkt"
+         "manual-ex.rkt"
+         "on-demand.rkt"
          scheme/string
          scheme/list
          (for-syntax racket/base)
diff --git a/collects/scribble/private/manual-scheme.rkt b/collects/scribble/private/manual-scheme.rkt
index 7d5467640c..bc0f59d112 100644
--- a/collects/scribble/private/manual-scheme.rkt
+++ b/collects/scribble/private/manual-scheme.rkt
@@ -1,12 +1,12 @@
 #lang racket/base
-(require "../decode.ss"
-         "../struct.ss"
-         "../scheme.ss"
-         "../search.ss"
-         "../basic.ss"
+(require "../decode.rkt"
+         "../struct.rkt"
+         "../scheme.rkt"
+         "../search.rkt"
+         "../basic.rkt"
          racket/list
-         "manual-utils.ss"
-         "manual-style.ss"
+         "manual-utils.rkt"
+         "manual-style.rkt"
          (for-syntax racket/base)
          (for-label racket/base))
 
diff --git a/collects/scribble/private/manual-sprop.rkt b/collects/scribble/private/manual-sprop.rkt
index 10c6399c72..8877870728 100644
--- a/collects/scribble/private/manual-sprop.rkt
+++ b/collects/scribble/private/manual-sprop.rkt
@@ -1,11 +1,11 @@
 #lang scheme/base
 
-(require "../html-properties.ss"
-         "../latex-properties.ss"
-         "on-demand.ss"
+(require "../html-properties.rkt"
+         "../latex-properties.rkt"
+         "on-demand.rkt"
          setup/main-collects
          scheme/promise)
-           
+
 (provide scheme-properties)
 
 (define-on-demand scheme-properties
diff --git a/collects/scribble/private/manual-style.rkt b/collects/scribble/private/manual-style.rkt
index 9b4091ecdc..2fa5c5911e 100644
--- a/collects/scribble/private/manual-style.rkt
+++ b/collects/scribble/private/manual-style.rkt
@@ -1,14 +1,14 @@
 #lang racket/base
-(require "../decode.ss"
-         "../struct.ss"
-         "../base.ss"
-         (only-in "../basic.ss" aux-elem itemize)
-         "../scheme.ss"
-         (only-in "../core.ss" make-style plain
+(require "../decode.rkt"
+         "../struct.rkt"
+         "../base.rkt"
+         (only-in "../basic.rkt" aux-elem itemize)
+         "../scheme.rkt"
+         (only-in "../core.rkt" make-style plain
                   make-nested-flow
                   [element? core:element?])
-         "manual-utils.ss"
-         "on-demand.ss"
+         "manual-utils.rkt"
+         "on-demand.rkt"
          "manual-sprop.rkt"
          racket/list
          racket/contract
diff --git a/collects/scribble/private/manual-tech.rkt b/collects/scribble/private/manual-tech.rkt
index 3e4d92caea..5f32d4d9ff 100644
--- a/collects/scribble/private/manual-tech.rkt
+++ b/collects/scribble/private/manual-tech.rkt
@@ -1,10 +1,10 @@
 #lang scheme/base
 (require scheme/contract
-         "../decode.ss"
-         "../struct.ss"
-         "../basic.ss"
-         "manual-utils.ss"
-         "manual-style.ss")
+         "../decode.rkt"
+         "../struct.rkt"
+         "../basic.rkt"
+         "manual-utils.rkt"
+         "manual-style.rkt")
 
 (provide/contract
  [deftech (() (#:style? boolean?) #:rest (listof pre-content?) . ->* . element?)]
diff --git a/collects/scribble/private/manual-unit.rkt b/collects/scribble/private/manual-unit.rkt
index 0e0330b817..6fe9ecdfd8 100644
--- a/collects/scribble/private/manual-unit.rkt
+++ b/collects/scribble/private/manual-unit.rkt
@@ -1,16 +1,16 @@
 #lang scheme/base
-(require "../decode.ss"
-         "../struct.ss"
-         "../scheme.ss"
-         "../search.ss"
-         "../basic.ss"
-         "manual-utils.ss"
-         "manual-vars.ss"
-         "manual-style.ss"
-         "manual-scheme.ss"
-         "manual-bind.ss"
-         "manual-ex.ss"
-         "manual-proc.ss"
+(require "../decode.rkt"
+         "../struct.rkt"
+         "../scheme.rkt"
+         "../search.rkt"
+         "../basic.rkt"
+         "manual-utils.rkt"
+         "manual-vars.rkt"
+         "manual-style.rkt"
+         "manual-scheme.rkt"
+         "manual-bind.rkt"
+         "manual-ex.rkt"
+         "manual-proc.rkt"
          scheme/contract
          (for-syntax scheme/base)
          (for-label scheme/base))
diff --git a/collects/scribble/private/manual-utils.rkt b/collects/scribble/private/manual-utils.rkt
index df4650859e..2eeb0779e5 100644
--- a/collects/scribble/private/manual-utils.rkt
+++ b/collects/scribble/private/manual-utils.rkt
@@ -1,8 +1,8 @@
 #lang scheme/base
-(require "../struct.ss"
-         "../decode.ss"
-         "../base.ss"
-         (only-in "../core.ss"
+(require "../struct.rkt"
+         "../decode.rkt"
+         "../base.rkt"
+         (only-in "../core.rkt"
                    content?)
          scheme/contract
          scheme/list)
diff --git a/collects/scribble/private/manual-vars.rkt b/collects/scribble/private/manual-vars.rkt
index 52dde6c561..8b457fbd2f 100644
--- a/collects/scribble/private/manual-vars.rkt
+++ b/collects/scribble/private/manual-vars.rkt
@@ -1,8 +1,8 @@
 #lang scheme/base
-(require "../decode.ss"
-         "../scheme.ss"
-         "../struct.ss"
-         (only-in "../core.ss" style-name)
+(require "../decode.rkt"
+         "../scheme.rkt"
+         "../struct.rkt"
+         (only-in "../core.rkt" style-name)
          scheme/contract
          (for-syntax scheme/base
                      syntax/kerncase
diff --git a/collects/scribble/private/render-utils.rkt b/collects/scribble/private/render-utils.rkt
index df1d232747..1abd03e7ba 100644
--- a/collects/scribble/private/render-utils.rkt
+++ b/collects/scribble/private/render-utils.rkt
@@ -1,5 +1,5 @@
 #lang scheme/base
-(require "../core.ss")
+(require "../core.rkt")
 
 (provide part-style?
          select-suffix
diff --git a/collects/scribble/racket.rkt b/collects/scribble/racket.rkt
index c632504244..8b9bf42703 100644
--- a/collects/scribble/racket.rkt
+++ b/collects/scribble/racket.rkt
@@ -1,9 +1,9 @@
 (module racket racket/base
-  (require "core.ss"
-           "basic.ss"
-           "search.ss"
-           "private/manual-sprop.ss"
-           "private/on-demand.ss"
+  (require "core.rkt"
+           "basic.rkt"
+           "search.rkt"
+           "private/manual-sprop.rkt"
+           "private/on-demand.rkt"
            mzlib/class
            mzlib/for
            syntax/modresolve
diff --git a/collects/scribble/run.rkt b/collects/scribble/run.rkt
index 131951ebd5..6ffdb8a6cf 100644
--- a/collects/scribble/run.rkt
+++ b/collects/scribble/run.rkt
@@ -1,16 +1,16 @@
 #lang racket/base
 
-(require "core.ss"
-         "base-render.ss"
-         "xref.ss"
+(require "core.rkt"
+         "base-render.rkt"
+         "xref.rkt"
          scheme/cmdline
          scheme/file
          scheme/class
          raco/command-name
-         (prefix-in text:  "text-render.ss")
-         (prefix-in html:  "html-render.ss")
-         (prefix-in latex: "latex-render.ss")
-         (prefix-in pdf:   "pdf-render.ss"))
+         (prefix-in text:  "text-render.rkt")
+         (prefix-in html:  "html-render.rkt")
+         (prefix-in latex: "latex-render.rkt")
+         (prefix-in pdf:   "pdf-render.rkt"))
 
 (define multi-html:render-mixin
   (lambda (%) (html:render-multi-mixin (html:render-mixin %))))
diff --git a/collects/scribble/scheme.rkt b/collects/scribble/scheme.rkt
index 67b1f198d6..e7b113194c 100644
--- a/collects/scribble/scheme.rkt
+++ b/collects/scribble/scheme.rkt
@@ -1,3 +1,3 @@
 #lang racket/base
-(require "racket.ss")
-(provide (all-from-out "racket.ss"))
+(require "racket.rkt")
+(provide (all-from-out "racket.rkt"))
diff --git a/collects/scribble/search.rkt b/collects/scribble/search.rkt
index f5187add3c..2db52b6c20 100644
--- a/collects/scribble/search.rkt
+++ b/collects/scribble/search.rkt
@@ -1,6 +1,6 @@
 (module search racket/base
-  (require "struct.ss"
-           "basic.ss"
+  (require "struct.rkt"
+           "basic.rkt"
            setup/main-collects
            syntax/modcode)
 
diff --git a/collects/scribble/sigplan/lang.rkt b/collects/scribble/sigplan/lang.rkt
index bcf43a5050..2f01623a3d 100644
--- a/collects/scribble/sigplan/lang.rkt
+++ b/collects/scribble/sigplan/lang.rkt
@@ -5,7 +5,7 @@
          scribble/decode
          scribble/sigplan
          racket/list
-         "../private/defaults.ss"
+         "../private/defaults.rkt"
          (for-syntax scheme/base))
 (provide (except-out (all-from-out scribble/doclang) #%module-begin)
          (all-from-out scribble/sigplan)
diff --git a/collects/scribble/srcdoc.rkt b/collects/scribble/srcdoc.rkt
index d3e2c0fbdb..2553b2f246 100644
--- a/collects/scribble/srcdoc.rkt
+++ b/collects/scribble/srcdoc.rkt
@@ -2,7 +2,7 @@
 
 (require scheme/contract
          (for-syntax scheme/base)
-         "provide-doc-transform.ss")
+         "provide-doc-transform.rkt")
 
 (provide require/doc
          provide/doc
diff --git a/collects/scribble/struct.rkt b/collects/scribble/struct.rkt
index d0b481e9c3..f3ff18f687 100644
--- a/collects/scribble/struct.rkt
+++ b/collects/scribble/struct.rkt
@@ -1,10 +1,10 @@
 #lang scheme/base
-(require (rename-in (except-in "core.ss"
+(require (rename-in (except-in "core.rkt"
                                target-url struct:target-url target-url? target-url-addr
                                deserialize-info:target-url-v0)
                     [make-target-url core:make-target-url])
-         "private/provide-structs.ss"
-         "html-properties.ss"
+         "private/provide-structs.rkt"
+         "html-properties.rkt"
          scheme/provide-syntax
          scheme/struct-info
          scheme/contract
diff --git a/collects/scribble/text-render.rkt b/collects/scribble/text-render.rkt
index c5ea4d1215..5c540cfee6 100644
--- a/collects/scribble/text-render.rkt
+++ b/collects/scribble/text-render.rkt
@@ -1,6 +1,5 @@
-
 (module text-render racket/base
-  (require "core.ss"
+  (require "core.rkt"
            racket/class
            racket/port)
   (provide render-mixin)
diff --git a/collects/scribble/text/lang.rkt b/collects/scribble/text/lang.rkt
index 3df5a5a990..1a8bf8362c 100644
--- a/collects/scribble/text/lang.rkt
+++ b/collects/scribble/text/lang.rkt
@@ -1,9 +1,9 @@
 #lang racket/base
 
-(require "syntax-utils.ss" "output.ss"
+(require "syntax-utils.rkt" "output.rkt"
          racket/promise racket/list racket/string)
 
 (provide (except-out (all-from-out racket/base) #%module-begin)
-         (all-from-out "output.ss" racket/promise racket/list racket/string)
+         (all-from-out "output.rkt" racket/promise racket/list racket/string)
          (rename-out [module-begin/text #%module-begin]
                      [begin/text text] [include/text include]))
diff --git a/collects/scribble/text/main.rkt b/collects/scribble/text/main.rkt
index 5cc7ae6a7e..b6cdb1e95b 100644
--- a/collects/scribble/text/main.rkt
+++ b/collects/scribble/text/main.rkt
@@ -1,7 +1,7 @@
 #lang racket/base
 
-(require "output.ss" "syntax-utils.ss"
+(require "output.rkt" "syntax-utils.rkt"
          racket/promise racket/list racket/string)
 
-(provide (all-from-out "output.ss" racket/promise racket/list racket/string)
+(provide (all-from-out "output.rkt" racket/promise racket/list racket/string)
          begin/text include/text)
diff --git a/collects/scribble/text/syntax-utils.rkt b/collects/scribble/text/syntax-utils.rkt
index fea2a06108..794ea84b0b 100644
--- a/collects/scribble/text/syntax-utils.rkt
+++ b/collects/scribble/text/syntax-utils.rkt
@@ -1,6 +1,6 @@
 #lang scheme/base
 
-(require "output.ss" (for-syntax scheme/base syntax/kerncase))
+(require "output.rkt" (for-syntax scheme/base syntax/kerncase))
 
 (provide module-begin/text begin/text include/text begin/collect
          process-begin/text)
@@ -172,7 +172,7 @@
      #'(process-begin/text begin/collect begin expr ...)]))
 
 ;; include for templates
-(require (for-syntax scheme/base (prefix-in scribble: "../reader.ss"))
+(require (for-syntax scheme/base (prefix-in scribble: "../reader.rkt"))
          scheme/include)
 (define-syntax-rule (include/text path-spec)
   (begin/text
diff --git a/collects/scribblings/draw/common.rkt b/collects/scribblings/draw/common.rkt
index 7af675239f..36acc9acd2 100644
--- a/collects/scribblings/draw/common.rkt
+++ b/collects/scribblings/draw/common.rkt
@@ -4,15 +4,15 @@
            scribble/eval
            racket/class
            racket/contract
-           "blurbs.ss"
-           (only-in "../reference/mz.ss" AllUnix exnraise))
+           "blurbs.rkt"
+           (only-in "../reference/mz.rkt" AllUnix exnraise))
   (provide (all-from-out scribble/manual)
            (all-from-out scribble/basic)
            (all-from-out scribble/eval)
            (all-from-out racket/class)
            (all-from-out racket/contract)
-           (all-from-out "blurbs.ss")
-           (all-from-out "../reference/mz.ss"))
+           (all-from-out "blurbs.rkt")
+           (all-from-out "../reference/mz.rkt"))
 
   (require (for-label racket/draw
                       racket/gui/base
diff --git a/collects/scribblings/foreign/utils.rkt b/collects/scribblings/foreign/utils.rkt
index aaae61cac8..0571ef0e54 100644
--- a/collects/scribblings/foreign/utils.rkt
+++ b/collects/scribblings/foreign/utils.rkt
@@ -3,7 +3,7 @@
 (require scribble/manual
          scribble/struct
          scribble/decode
-         (only-in "../inside/utils.ss" cpp)
+         (only-in "../inside/utils.rkt" cpp)
          (for-syntax racket/base)
          (for-label racket/base
                     racket/contract
diff --git a/collects/scribblings/framework/main-extracts.rkt b/collects/scribblings/framework/main-extracts.rkt
index 9c8e329815..443097475f 100644
--- a/collects/scribblings/framework/main-extracts.rkt
+++ b/collects/scribblings/framework/main-extracts.rkt
@@ -1,4 +1,4 @@
 #lang scheme/base
 (require scribble/extract)
 
-(provide-extracted (lib "main.ss" "framework"))
+(provide-extracted (lib "framework/main.rkt"))
diff --git a/collects/scribblings/gui/common.rkt b/collects/scribblings/gui/common.rkt
index 4ead8e0677..6998ba5250 100644
--- a/collects/scribblings/gui/common.rkt
+++ b/collects/scribblings/gui/common.rkt
@@ -1,17 +1,16 @@
-
 (module common racket/base
   (require scribble/manual
            scribble/basic
            racket/class
            racket/contract
-           "blurbs.ss"
-           (only-in "../reference/mz.ss" AllUnix exnraise))
+           "blurbs.rkt"
+           (only-in "../reference/mz.rkt" AllUnix exnraise))
   (provide (all-from-out scribble/manual)
            (all-from-out scribble/basic)
            (all-from-out racket/class)
            (all-from-out racket/contract)
-           (all-from-out "blurbs.ss")
-           (all-from-out "../reference/mz.ss"))
+           (all-from-out "blurbs.rkt")
+           (all-from-out "../reference/mz.rkt"))
 
   (require (for-label racket/gui/base
                       racket/class
diff --git a/collects/scribblings/guide/contracts-examples/1-test.rkt b/collects/scribblings/guide/contracts-examples/1-test.rkt
index f2bbbb1f24..6547a7de94 100644
--- a/collects/scribblings/guide/contracts-examples/1-test.rkt
+++ b/collects/scribblings/guide/contracts-examples/1-test.rkt
@@ -1,5 +1,5 @@
 #lang racket
-(require rackunit rackunit/text-ui "1.ss" "1b.ss")
+(require rackunit rackunit/text-ui "1.rkt" "1b.rkt")
 
 (add (make-basic-customer 'mf "matthias" "brookstone"))
 (add (make-basic-customer 'rf "robby" "beverly hills park"))
diff --git a/collects/scribblings/guide/contracts-examples/1b.rkt b/collects/scribblings/guide/contracts-examples/1b.rkt
index 803c92df26..2b3e1b1087 100644
--- a/collects/scribblings/guide/contracts-examples/1b.rkt
+++ b/collects/scribblings/guide/contracts-examples/1b.rkt
@@ -1,6 +1,6 @@
 #lang racket
 
-(require "1.ss") ;; the module just above
+(require "1.rkt") ;; the module just above
 
 ;; implementation
 ;; [listof (list basic-customer? secret-info)]
diff --git a/collects/scribblings/guide/contracts-examples/2-test.rkt b/collects/scribblings/guide/contracts-examples/2-test.rkt
index 0343fc3224..3c416abf29 100644
--- a/collects/scribblings/guide/contracts-examples/2-test.rkt
+++ b/collects/scribblings/guide/contracts-examples/2-test.rkt
@@ -1,5 +1,5 @@
 #lang racket
-(require rackunit rackunit/text-ui "2.ss")
+(require rackunit rackunit/text-ui "2.rkt")
 
 (define s0 (initialize (flat-contract integer?) =))
 (define s2 (push (push s0 2) 1))
diff --git a/collects/scribblings/guide/contracts-examples/3-test.rkt b/collects/scribblings/guide/contracts-examples/3-test.rkt
index f25cb4ac4e..ae3fd0f879 100644
--- a/collects/scribblings/guide/contracts-examples/3-test.rkt
+++ b/collects/scribblings/guide/contracts-examples/3-test.rkt
@@ -1,5 +1,5 @@
 #lang racket
-(require rackunit rackunit/text-ui "3.ss")
+(require rackunit rackunit/text-ui "3.rkt")
 
 (define d0 (initialize (flat-contract integer?) =))
 (define d (put (put (put d0 'a 2) 'b 2) 'c 1))
diff --git a/collects/scribblings/guide/contracts-examples/5-test.rkt b/collects/scribblings/guide/contracts-examples/5-test.rkt
index 617a87883a..69c27c0108 100644
--- a/collects/scribblings/guide/contracts-examples/5-test.rkt
+++ b/collects/scribblings/guide/contracts-examples/5-test.rkt
@@ -1,5 +1,5 @@
 #lang racket
-(require rackunit rackunit/text-ui "5.ss")
+(require rackunit rackunit/text-ui "5.rkt")
 
 (define s (put (put (initialize (flat-contract integer?) =) 2) 1))
 
diff --git a/collects/scribblings/guide/guide-utils.rkt b/collects/scribblings/guide/guide-utils.rkt
index b54b14988e..deb3f552c5 100644
--- a/collects/scribblings/guide/guide-utils.rkt
+++ b/collects/scribblings/guide/guide-utils.rkt
@@ -3,7 +3,7 @@
            scribble/struct
            scribble/decode
            scribble/eval
-           "../icons.ss")
+           "../icons.rkt")
 
   (require (for-label racket/base))
   (provide (for-label (all-from-out racket/base)))
diff --git a/collects/scribblings/htdp-langs/prim-ops.rkt b/collects/scribblings/htdp-langs/prim-ops.rkt
index 69abc9873b..88894868ac 100644
--- a/collects/scribblings/htdp-langs/prim-ops.rkt
+++ b/collects/scribblings/htdp-langs/prim-ops.rkt
@@ -1,6 +1,6 @@
 #reader scribble/reader
 #lang scheme/base
-(require "common.ss"
+(require "common.rkt"
          scribble/decode
          scribble/struct
          scribble/scheme
diff --git a/collects/scribblings/htdp-langs/std-grammar.rkt b/collects/scribblings/htdp-langs/std-grammar.rkt
index 0af4033b55..2a57567457 100644
--- a/collects/scribblings/htdp-langs/std-grammar.rkt
+++ b/collects/scribblings/htdp-langs/std-grammar.rkt
@@ -1,6 +1,6 @@
 #reader scribble/reader
 #lang scheme/base
-(require "common.ss"
+(require "common.rkt"
          scribble/decode
          (for-label lang/htdp-beginner-abbr))
 
diff --git a/collects/scribblings/main/private/make-search.rkt b/collects/scribblings/main/private/make-search.rkt
index 7b986a6f15..9e1f53450b 100644
--- a/collects/scribblings/main/private/make-search.rkt
+++ b/collects/scribblings/main/private/make-search.rkt
@@ -16,7 +16,7 @@
          (only-in scheme/class send)
          (only-in xml xexpr->string)
          (only-in setup/dirs find-doc-dir)
-         "utils.ss"
+         "utils.rkt"
          scheme/runtime-path)
 
 (provide make-search)
diff --git a/collects/scribblings/main/private/manuals.rkt b/collects/scribblings/main/private/manuals.rkt
index 230f22d00a..16de75f74b 100644
--- a/collects/scribblings/main/private/manuals.rkt
+++ b/collects/scribblings/main/private/manuals.rkt
@@ -6,7 +6,7 @@
          setup/main-collects
          scheme/list
          scheme/match
-         "../config.ss")
+         "../config.rkt")
 
 (provide make-start-page)
 
diff --git a/collects/scribblings/main/private/utils.rkt b/collects/scribblings/main/private/utils.rkt
index 9923088f30..6f21ee6c31 100644
--- a/collects/scribblings/main/private/utils.rkt
+++ b/collects/scribblings/main/private/utils.rkt
@@ -1,7 +1,7 @@
 #reader scribble/reader
 #lang scheme/base
 
-(require "../config.ss"
+(require "../config.rkt"
          scribble/manual
          scribble/core
          scribble/html-properties
@@ -77,7 +77,7 @@
                      (list @script{SetPLTRoot("@(version)", "@up-path")@";"})
                      '()))))
 
-;; FIXME: Use this to avoid hard-wiring manual titles and paths in config.ss
+;; FIXME: Use this to avoid hard-wiring manual titles and paths in config.rkt
 (define (resolve s [f s])
   (resolved-module-path-name
    (module-path-index-resolve
diff --git a/collects/scribblings/reference/ellipses.rkt b/collects/scribblings/reference/ellipses.rkt
index 1eee7b22d7..24e78f3ee1 100644
--- a/collects/scribblings/reference/ellipses.rkt
+++ b/collects/scribblings/reference/ellipses.rkt
@@ -1,7 +1,7 @@
 (module ellipses scheme/base
   (require scribble/manual
-           "ellipses-defn.ss"
-           (for-label "ellipses-defn.ss"))
+           "ellipses-defn.rkt"
+           (for-label "ellipses-defn.rkt"))
 
   (provide ellipses-defn
            ellipses-id)
diff --git a/collects/scribblings/reference/match-grammar.rkt b/collects/scribblings/reference/match-grammar.rkt
index 871931f260..1735d66c8f 100644
--- a/collects/scribblings/reference/match-grammar.rkt
+++ b/collects/scribblings/reference/match-grammar.rkt
@@ -1,5 +1,5 @@
 #lang scheme/base
-(require "match-parse.ss")
+(require "match-parse.rkt")
 
 (provide match-grammar)
 
diff --git a/collects/scribblings/reference/mz.rkt b/collects/scribblings/reference/mz.rkt
index bf06108b69..241cb8afcf 100644
--- a/collects/scribblings/reference/mz.rkt
+++ b/collects/scribblings/reference/mz.rkt
@@ -4,7 +4,7 @@
            scribble/eval
            scribble/decode
            racket/contract
-           "../icons.ss")
+           "../icons.rkt")
   
   (provide (all-from-out scribble/manual)
            (all-from-out scribble/eval)
diff --git a/collects/scriblib/figure.rkt b/collects/scriblib/figure.rkt
index 34525f6c1a..589bf75f1f 100644
--- a/collects/scriblib/figure.rkt
+++ b/collects/scriblib/figure.rkt
@@ -6,7 +6,7 @@
          scribble/html-properties
          scribble/latex-properties
          setup/main-collects
-         "private/counter.ss")
+         "private/counter.rkt")
 
 (provide figure
          figure*
diff --git a/collects/scriblib/footnote.rkt b/collects/scriblib/footnote.rkt
index cc3957b5de..81dda9672c 100644
--- a/collects/scriblib/footnote.rkt
+++ b/collects/scriblib/footnote.rkt
@@ -6,7 +6,7 @@
          scribble/latex-properties
          racket/promise
          setup/main-collects
-         "private/counter.ss")
+         "private/counter.rkt")
 
 (provide note
          define-footnote)
diff --git a/collects/scriblib/gui-eval.rkt b/collects/scriblib/gui-eval.rkt
index 0546b6aa6d..fae4408188 100644
--- a/collects/scriblib/gui-eval.rkt
+++ b/collects/scriblib/gui-eval.rkt
@@ -7,7 +7,7 @@
          racket/file
          racket/runtime-path
          racket/serialize
-         "private/gui-eval-exn.ss"
+         "private/gui-eval-exn.rkt"
          racket/system
          racket/sandbox
          (for-syntax racket/base))
diff --git a/collects/setup/configtab.rkt b/collects/setup/configtab.rkt
index e60c9162dd..364b095534 100644
--- a/collects/setup/configtab.rkt
+++ b/collects/setup/configtab.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-;; Defines a language to be used by the "config.ss" file
+;; Defines a language to be used by the "config.rkt" file
 
 (require racket/promise
          (for-syntax racket/base))
@@ -9,7 +9,7 @@
          #%datum quote)
 
 ;; These are the name that need to be provided
-;;  by the "config.ss" library:
+;;  by the "config.rkt" library:
 (define-for-syntax path-exports
   '(doc-dir
     doc-search-dirs
diff --git a/collects/setup/dirs.rkt b/collects/setup/dirs.rkt
index 20c75e2c6e..f03ee4d910 100644
--- a/collects/setup/dirs.rkt
+++ b/collects/setup/dirs.rkt
@@ -4,7 +4,7 @@
          (prefix-in config: config)
          compiler/private/winutf16
          compiler/private/mach-o
-         "private/main-collects.ss")
+         "private/main-collects.rkt")
 
 (provide (rename-out [config:absolute-installation? absolute-installation?]))
 
diff --git a/collects/setup/infotab.rkt b/collects/setup/infotab.rkt
index 1301c8bc3c..09714287b9 100644
--- a/collects/setup/infotab.rkt
+++ b/collects/setup/infotab.rkt
@@ -1,5 +1,4 @@
-
-;; Defines a language to be used by info.ss files
+;; Defines a language to be used by info.rkt files
 
 #lang scheme/base
 (require (for-syntax scheme/base))
@@ -33,12 +32,12 @@
               defn ...
               (define #%info-lookup
                 (case-lambda
-                  [(n) (#%info-lookup n (lambda () (error 'info.ss "no info for ~a" n)))]
+                  [(n) (#%info-lookup n (lambda () (error 'info.rkt "no info for ~a" n)))]
                   [(n fail)
                    (unless (and (procedure? fail)
                                 (procedure-arity-includes? fail 0))
                      (error
-                      'info.ss
+                      'info.rkt
                       "expected second argument to be a procedure that takes no arguments, got: ~e"
                       fail))
                    (case n
diff --git a/collects/setup/main-collects.rkt b/collects/setup/main-collects.rkt
index 83edc40546..04fbbb01f4 100644
--- a/collects/setup/main-collects.rkt
+++ b/collects/setup/main-collects.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-(require "dirs.ss" "path-relativize.ss")
+(require "dirs.rkt" "path-relativize.rkt")
 
 (provide path->main-collects-relative
          main-collects-relative->path)
@@ -10,4 +10,3 @@
                    'collects
                    'path->main-collects-relative
                    'main-collects-relative->path))
-
diff --git a/collects/setup/main-doc.rkt b/collects/setup/main-doc.rkt
index 57c3d87377..ba4c4c7fef 100644
--- a/collects/setup/main-doc.rkt
+++ b/collects/setup/main-doc.rkt
@@ -1,5 +1,5 @@
 #lang mzscheme
-(require "dirs.ss" "path-relativize.ss")
+(require "dirs.rkt" "path-relativize.rkt")
 
 (provide path->main-doc-relative
          main-doc-relative->path)
@@ -10,4 +10,3 @@
                    'doc
                    'path->main-doc-relative
                    'main-doc-relative->path))
-
diff --git a/collects/setup/main.rkt b/collects/setup/main.rkt
index d3012cee9c..cda5844a39 100644
--- a/collects/setup/main.rkt
+++ b/collects/setup/main.rkt
@@ -4,7 +4,7 @@
 ;; startup stub parses the command line and either disables .zos or
 ;; installs cm for loading Setup PLT.
 
-;; Note that this file is listed in "info.ss" so that it never gets a
+;; Note that this file is listed in "info.rkt" so that it never gets a
 ;; .zo file. Do not `require' this module from anywhere, not even 
 ;; `for-label', otherwise it could get a .zo anyway.
 
@@ -90,15 +90,15 @@
       ;; This has to be dynamic, so we get a chance to turn off compiled
       ;;  file loading, and so it can be in a separate namespace.
       (let-values ([(mk trust-zos)
-		    ;; Load cm.ss into its own namespace, so that cm compiles
+		    ;; Load cm.rkt into its own namespace, so that cm compiles
 		    ;;  itself and its required modules in the right order
 		    ;;  (i.e., when some module requires cm or one of its
 		    ;;  required modules)
-		    ;; Since cm.ss pulls in quite a lot of code itself, we
+		    ;; Since cm.rkt pulls in quite a lot of code itself, we
 		    ;;  would like to load using .zo files. But if we discover
 		    ;;  any date mismatch in the loading process, abort and
 		    ;;  try again without .zo files. If .zo files are newer
-		    ;;  than .ss files but a required file is newer than its
+		    ;;  than .rkt files but a required file is newer than its
 		    ;;  requring file, we won't notice, but that
 		    ;;  shouldn't happen for a reaonsbaly maintained
 		    ;;  tree, and there's always --clean to turn this
@@ -159,7 +159,7 @@
                                                   (lambda () (raise exn)))
                                                  (escape
                                                   (lambda () (loop #t)))))])
-			     ;; Here's the main dynamic load of "cm.ss":
+			     ;; Here's the main dynamic load of "cm.rkt":
 			     (let ([mk
 				    (dynamic-require 'compiler/cm
 						     'make-compilation-manager-load/use-compiled-handler)]
diff --git a/collects/setup/option-unit.rkt b/collects/setup/option-unit.rkt
index 1dd8e2b5df..88650880e0 100644
--- a/collects/setup/option-unit.rkt
+++ b/collects/setup/option-unit.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 (require scheme/unit
          racket/future
-         "option-sig.ss")
+         "option-sig.rkt")
 
 (provide setup:option@ set-flag-params)
 
diff --git a/collects/setup/pack.rkt b/collects/setup/pack.rkt
index 2e5d80689f..e3462073ca 100644
--- a/collects/setup/pack.rkt
+++ b/collects/setup/pack.rkt
@@ -240,7 +240,7 @@
                                                 (i which (lambda () null))
                                                 null)])
                                       (unless (coll-list? rl)
-                                        (error 'mzc "bad ~a specification in info.ss for collection ~s"
+                                        (error 'mzc "bad ~a specification in info.rkt for collection ~s"
                                                which src-cp))
                                       rl))
                                   infos collections)))])
@@ -276,7 +276,7 @@
                                        (andmap integer? v))
                             (error
                              'mzc
-                             "bad version specification in info.ss for collection ~s"
+                             "bad version specification in info.rkt for collection ~s"
                              r))
                           (list r v))
                         (list r null)))))
diff --git a/collects/setup/plt-installer-unit.rkt b/collects/setup/plt-installer-unit.rkt
index c68a91cd5f..11116c36b1 100644
--- a/collects/setup/plt-installer-unit.rkt
+++ b/collects/setup/plt-installer-unit.rkt
@@ -1,11 +1,10 @@
-
 (module plt-installer-unit mzscheme
   (require mzlib/unit
            mred/mred-sig
            mzlib/class
            mzlib/etc
-           "plt-installer-sig.ss"
-           (prefix single: "plt-single-installer.ss")
+           "plt-installer-sig.rkt"
+           (prefix single: "plt-single-installer.rkt")
            string-constants)
 
   (provide plt-installer@)
diff --git a/collects/setup/plt-installer.rkt b/collects/setup/plt-installer.rkt
index 8dbcff8a38..9021508991 100644
--- a/collects/setup/plt-installer.rkt
+++ b/collects/setup/plt-installer.rkt
@@ -1,7 +1,7 @@
 (module plt-installer mzscheme
   (require mzlib/unit
-           "plt-installer-sig.ss"
-           "plt-installer-unit.ss"
+           "plt-installer-sig.rkt"
+           "plt-installer-unit.rkt"
            mred/mred-unit
            mred/mred-sig)
 
@@ -10,4 +10,3 @@
     (import) (export setup:plt-installer^)
     (link standard-mred@ plt-installer@))
   (define-values/invoke-unit/infer plt-installer+mred@))
-
diff --git a/collects/setup/plt-single-installer.rkt b/collects/setup/plt-single-installer.rkt
index 6cdb328dde..382bdea658 100644
--- a/collects/setup/plt-single-installer.rkt
+++ b/collects/setup/plt-single-installer.rkt
@@ -2,17 +2,17 @@
   (require mzlib/unit
            mzlib/etc
            
-	   ;; All the rest are to get the imports for setup@:
-	   "option-sig.ss"
-	   "setup-unit.ss"
-	   "option-unit.ss"
-	   launcher/launcher-sig
-	   launcher/launcher-unit
-	   dynext/dynext-sig
-	   dynext/dynext-unit
-	   compiler/sig
-	   compiler/option-unit
-	   compiler/compiler-unit)
+           ;; All the rest are to get the imports for setup@:
+           "option-sig.rkt"
+           "setup-unit.rkt"
+           "option-unit.rkt"
+           launcher/launcher-sig
+           launcher/launcher-unit
+           dynext/dynext-sig
+           dynext/dynext-unit
+           compiler/sig
+           compiler/option-unit
+           compiler/compiler-unit)
 
   (provide run-single-installer install-planet-package clean-planet-package reindex-user-documentation)
 
diff --git a/collects/setup/private/main-collects.rkt b/collects/setup/private/main-collects.rkt
index e0c6319ba8..6108826973 100644
--- a/collects/setup/private/main-collects.rkt
+++ b/collects/setup/private/main-collects.rkt
@@ -9,7 +9,7 @@
   ;; Path normalization is not really necessary by any existing code,
   ;; but there might be applications that rely on these paths, so it's
   ;; best to do some minor normalization.  This is similar to what
-  ;; "main-collects.ss" does. Don't use this with 'exec-file, however,
+  ;; "main-collects.rkt" does. Don't use this with 'exec-file, however,
   ;; because the treatment of an executable path can very depending
   ;; on whether it has a path prefix or not.
   (define (system-path* what)
diff --git a/collects/setup/private/omitted-paths.rkt b/collects/setup/private/omitted-paths.rkt
index d1286488c0..cda020a68c 100644
--- a/collects/setup/private/omitted-paths.rkt
+++ b/collects/setup/private/omitted-paths.rkt
@@ -2,14 +2,14 @@
 
 ;; `omitted-paths' returns a list of omitted file and subdirectory names for a
 ;; given directory, or 'all if the directory is completely omitted.  Considers
-;; the local info.ss as well as info.ss in parent directories all the way to a
+;; the local info.rkt as well as info.rkt in parent directories all the way to a
 ;; collection root.  (Could be a bit easier using `find-relevant-directories',
 ;; but it needs to be available for setup-plt, before the "info-domain" caches
 ;; are created.)
 
 (provide omitted-paths)
 
-(require scheme/path scheme/list scheme/promise "../dirs.ss" "lib-roots.ss")
+(require scheme/path scheme/list scheme/promise "../dirs.rkt" "lib-roots.rkt")
 
 ;; An entry for each collections root that holds a hash table.  The hash table
 ;; maps a reversed list of subpath elements to the exploded omitted-paths
diff --git a/collects/setup/scribble.rkt b/collects/setup/scribble.rkt
index 35a7eda501..bb8db7aef7 100644
--- a/collects/setup/scribble.rkt
+++ b/collects/setup/scribble.rkt
@@ -1,11 +1,11 @@
 #lang scheme/base
 
-(require "getinfo.ss"
-         "dirs.ss"
+(require "getinfo.rkt"
+         "dirs.rkt"
          "path-to-relative.rkt"
-         "private/path-utils.ss"
-         "main-collects.ss"
-         "main-doc.ss"
+         "private/path-utils.rkt"
+         "main-collects.rkt"
+         "main-doc.rkt"
          "parallel-do.rkt"
          scheme/class
          scheme/list
@@ -789,7 +789,7 @@
       (namespace-attach-module ns 'scribble/base-render p)
       (namespace-attach-module ns 'scribble/html-render p)
       ;; This is here for de-serialization; we need a better repair than
-      ;;  hard-wiring the "manual.ss" library:
+      ;;  hard-wiring the "manual.rkt" library:
       (namespace-attach-module ns 'scribble/manual p)
       (parameterize ([current-namespace p])
         (call-in-nested-thread (lambda () (dynamic-require mod-path 'doc)))))))
diff --git a/collects/setup/setup-cmdline.rkt b/collects/setup/setup-cmdline.rkt
index 6b75f07422..4c669d0f37 100644
--- a/collects/setup/setup-cmdline.rkt
+++ b/collects/setup/setup-cmdline.rkt
@@ -1,7 +1,7 @@
 #lang racket/base
 
 ;; Command-line parsing is in its own module because it has to be used
-;;  both in setup.ss (pre-zo, pre-cm) and setup-go.ss (use zos and cm).
+;;  both in setup.ss (pre-zo, pre-cm) and setup-go.rkt (use zos and cm).
 ;; This means that command lines will be parsed twice.
 
 (require racket/cmdline
@@ -13,7 +13,7 @@
 ;; The result of parse-cmdline is three lists:
 ;;  - An assoc list mapping flag symbols to booleans
 ;;     (nearly all symbols correspond to parameter names
-;;      in setup-go.ss)
+;;      in setup-go.rkt)
 ;;  - A list of specific collections
 ;;  - A list of archives
 
diff --git a/collects/setup/setup-go.rkt b/collects/setup/setup-go.rkt
index 0ff74ac8a5..24f72ab735 100644
--- a/collects/setup/setup-go.rkt
+++ b/collects/setup/setup-go.rkt
@@ -1,12 +1,11 @@
-
 (module setup-go mzscheme
-  (require "setup-cmdline.ss"
-	   mzlib/unit
+  (require "setup-cmdline.rkt"
+           mzlib/unit
 
-	    "option-sig.ss"
-	    "setup-unit.ss"
-	    "option-unit.ss"
-	    compiler/cm)
+           "option-sig.rkt"
+           "setup-unit.rkt"
+           "option-unit.rkt"
+           compiler/cm)
 
   (define-values/invoke-unit/infer setup:option@)
 
diff --git a/collects/setup/unpack.rkt b/collects/setup/unpack.rkt
index a903392256..7a181f6827 100644
--- a/collects/setup/unpack.rkt
+++ b/collects/setup/unpack.rkt
@@ -1,14 +1,13 @@
-
 (module unpack mzscheme
 
   (require mzlib/etc
-	   mzlib/inflate
-	   mzlib/file
+           mzlib/inflate
+           mzlib/file
            mzlib/list
            mzlib/port
-	   net/base64
-	   setup/getinfo
-	   "dirs.ss")
+           net/base64
+           setup/getinfo
+           "dirs.rkt")
 
   (provide unpack
            fold-plt-archive)
diff --git a/collects/setup/winvers-change.rkt b/collects/setup/winvers-change.rkt
index e04531cded..76a39ac491 100644
--- a/collects/setup/winvers-change.rkt
+++ b/collects/setup/winvers-change.rkt
@@ -5,7 +5,7 @@
 ;; "xxxxxxx" in their name by a "NNN_NNN" version number, and will also do this
 ;; rewrite in all files.  (Actually looking for a few known string templates,
 ;; to be safe.)  Note that this is done *in-place*, so it will not work from a
-;; running Racket.exe on Windows -- "winvers.ss" uses a trick of making a copy
+;; running Racket.exe on Windows -- "winvers.rkt" uses a trick of making a copy
 ;; of the binary and restarting that copy for the actual change.
 
 #lang scheme/base
diff --git a/collects/setup/winvers.rkt b/collects/setup/winvers.rkt
index 45451b29b5..7d9dcd907d 100644
--- a/collects/setup/winvers.rkt
+++ b/collects/setup/winvers.rkt
@@ -1,9 +1,9 @@
-;; This is a wrapper around `winvers-change.ss' to patch binary files with the
+;; This is a wrapper around "winvers-change.rkt" to patch binary files with the
 ;; current version number.
 
 #lang scheme/base
 
-(require mzlib/file "main-collects.ss" "dirs.ss")
+(require mzlib/file "main-collects.rkt" "dirs.rkt")
 
 (define (make-copy)
   (let* ([tmpdir (find-system-path 'temp-dir)]
diff --git a/collects/setup/xref.rkt b/collects/setup/xref.rkt
index a9f60d3edf..ab67b094ff 100644
--- a/collects/setup/xref.rkt
+++ b/collects/setup/xref.rkt
@@ -3,8 +3,8 @@
 (require scribble/xref
          scheme/fasl
          scheme/path
-         "getinfo.ss"
-         "private/path-utils.ss")
+         "getinfo.rkt"
+         "private/path-utils.rkt")
 
 (provide load-collections-xref)
 
diff --git a/collects/sgl/examples/alpha.rkt b/collects/sgl/examples/alpha.rkt
index e54e385d8c..a0fdc8e44d 100644
--- a/collects/sgl/examples/alpha.rkt
+++ b/collects/sgl/examples/alpha.rkt
@@ -5,7 +5,7 @@
    mred
    sgl/gl
    sgl/gl-vectors
-   "gl-frame.ss")
+   "gl-frame.rkt")
   
   ;; texture
   ;; This needs to be here and not in gl-init because of some weirdness in the
diff --git a/collects/sgl/examples/gears.rkt b/collects/sgl/examples/gears.rkt
index 71d6f88a49..1e1bc2fbf2 100644
--- a/collects/sgl/examples/gears.rkt
+++ b/collects/sgl/examples/gears.rkt
@@ -1,4 +1,4 @@
-;; $Id: gears.ss,v 1.8 2005/01/12 12:49:10 mflatt Exp $
+;; $Id: gears.rkt,v 1.8 2005/01/12 12:49:10 mflatt Exp $
 ;;
 ;; This is a version of the venerable "gears" demo for PLT Scheme 200 using
 ;; Scott Owens' SGL OpenGL bindings.  It was ported from "glxgears.c" 1.3 from
@@ -23,10 +23,10 @@
 ;;     GLUT).  Port by Brian Paul 23 March 2001.
 ;;
 ;; To run, evaluate this file in DrRacket in the "module" language level,
-;; or execute "mred -qu gears.ss" from your OS shell.
+;; or execute "mred -qu gears.rkt" from your OS shell.
 ;;
 ;; Scheme port by Neil W. Van Dyke <neil@neilvandyke.org>, 23 November 2002.
-;; Originally called glxgears.ss.  Minor modifications since.
+;; Originally called glxgears.rkt.  Minor modifications since.
 ;; See "http://www.neilvandyke.org/opengl-plt/" for more information.
 ;;
 ;; Updated to newer sgl interface by Scott Owens
@@ -339,7 +339,7 @@
 
     (super-instantiate () (style '(gl no-autoclear)))))
 (define (f)
-  (let* ((f (make-object frame% "gears.ss" #f))
+  (let* ((f (make-object frame% "gears.rkt" #f))
          (c (instantiate gears-canvas% (f) (min-width 300) (min-height 300))))
     (send f create-status-line)
     (when controls?
diff --git a/collects/sgl/gl-vectors.rkt b/collects/sgl/gl-vectors.rkt
index 7c58666cf3..801bd05bae 100644
--- a/collects/sgl/gl-vectors.rkt
+++ b/collects/sgl/gl-vectors.rkt
@@ -1,6 +1,6 @@
 (module gl-vectors mzscheme
   (require mzlib/foreign
-           "gl-types.ss")
+           "gl-types.rkt")
   
   (define-syntax gl-vector-binop
     (syntax-rules ()
diff --git a/collects/sgl/gl.rkt b/collects/sgl/gl.rkt
index c6c3b1c0cc..0eb835297f 100644
--- a/collects/sgl/gl.rkt
+++ b/collects/sgl/gl.rkt
@@ -1,7 +1,7 @@
 #lang mzscheme
 (require mzlib/foreign
-         "gl-types.ss"
-         "gl-vectors.ss")
+         "gl-types.rkt"
+         "gl-vectors.rkt")
 
 (unsafe!)
 
diff --git a/collects/sgl/main.rkt b/collects/sgl/main.rkt
index 96d3d64aac..8d3bfd815a 100644
--- a/collects/sgl/main.rkt
+++ b/collects/sgl/main.rkt
@@ -1,3 +1,3 @@
 #lang scheme/base
-(require (prefix-in gl- "sgl.ss"))
-(provide (all-from-out "sgl.ss"))
+(require (prefix-in gl- "sgl.rkt"))
+(provide (all-from-out "sgl.rkt"))
diff --git a/collects/sgl/sgl.rkt b/collects/sgl/sgl.rkt
index 518c6b909d..923a0234a9 100644
--- a/collects/sgl/sgl.rkt
+++ b/collects/sgl/sgl.rkt
@@ -15,8 +15,8 @@
 #lang mzscheme
 
 (require mzlib/etc
-         "gl-vectors.ss"
-         "gl.ss")
+         "gl-vectors.rkt"
+         "gl.rkt")
 
 (define-syntax (_provide stx)
   (syntax-case stx ()
diff --git a/collects/sirmail/folderr.rkt b/collects/sirmail/folderr.rkt
index 4322495a9f..c4019564b3 100644
--- a/collects/sirmail/folderr.rkt
+++ b/collects/sirmail/folderr.rkt
@@ -1,4 +1,3 @@
-
 (module folderr mzscheme
   (require mzlib/unit
            mzlib/class
@@ -8,8 +7,8 @@
   (require mzlib/list
            mzlib/etc)
   
-  (require "sirmails.ss"
-           "pref.ss")
+  (require "sirmails.rkt"
+           "pref.rkt")
   
   (require net/imap-sig)
   
diff --git a/collects/sirmail/info.rkt b/collects/sirmail/info.rkt
index bd1bf4cbe1..741f0d0425 100644
--- a/collects/sirmail/info.rkt
+++ b/collects/sirmail/info.rkt
@@ -1,6 +1,6 @@
 #lang setup/infotab
 
-(define mred-launcher-libraries (list "sirmail.ss"))
+(define mred-launcher-libraries (list "sirmail.rkt"))
 (define mred-launcher-names (list "SirMail"))
-(define compile-omit-paths '("recover.ss"))
+(define compile-omit-paths '("recover.rkt"))
 (define requires '(("mred") ("openssl")))
diff --git a/collects/sirmail/main.rkt b/collects/sirmail/main.rkt
index 12801022f6..5a6bde9158 100644
--- a/collects/sirmail/main.rkt
+++ b/collects/sirmail/main.rkt
@@ -1,3 +1,2 @@
-
 (module main scheme/base
-  (require "sirmail.ss"))
+  (require "sirmail.rkt"))
diff --git a/collects/sirmail/optionr.rkt b/collects/sirmail/optionr.rkt
index fb90dc52ca..147e15fbdd 100644
--- a/collects/sirmail/optionr.rkt
+++ b/collects/sirmail/optionr.rkt
@@ -1,19 +1,18 @@
-
 (module optionr mzscheme
   (require mzlib/unit
-	   mzlib/string)
+           mzlib/string)
 
   (require net/imap-sig
            mred/mred-sig
-	   framework)
+           framework)
 
-  (require "sirmails.ss"
-	   "pref.ss")
+  (require "sirmails.rkt"
+           "pref.rkt")
 
   (define shared-password #f)
 
   ;; The option@ unit gets instanted afresh for every window, but
-  ;; it defers practically all of its work to the "pref.ss" module
+  ;; it defers practically all of its work to the "pref.rkt" module
   ;; (which is only instantiated once).
   
   (provide option@)
diff --git a/collects/sirmail/readr.rkt b/collects/sirmail/readr.rkt
index df8efd1bb4..f65189e8d0 100644
--- a/collects/sirmail/readr.rkt
+++ b/collects/sirmail/readr.rkt
@@ -1,4 +1,3 @@
-
 ;; This module implements the mail-reading window as a unit. The
 ;; unit is instantiated once for each window.
 
@@ -7,7 +6,7 @@
 ;;   * Always use `as-background' when communicating with the
 ;;     server. That way, the user can kill the window if necessary.
 ;;     use `enable-main-frame' for the first argument to `as-background'.
-;;     The `as-background' function is defined in "utilr.ss".
+;;     The `as-background' function is defined in "utilr.rkt".
 ;;
 
 (module readr mzscheme
@@ -20,12 +19,12 @@
 
   (require mzlib/string
            mzlib/list
-	   mzlib/thread
-           "spell.ss")
+           mzlib/thread
+           "spell.rkt")
 
-  (require "sirmails.ss")
+  (require "sirmails.rkt")
 
-  (require "pref.ss")
+  (require "pref.rkt")
 
   (require net/imap-sig
 	   net/smtp-sig
@@ -2015,7 +2014,7 @@
                  (sleep 10)
                  (loop)))))))
 
-      ;; copied from framerok/private/frame.sss -- be sure to propagate fixes....
+      ;; copied from framerok/private/frame.rkt -- be sure to propagate fixes....
       ;; or establish single point of control.
       (define (format-number n)
 	(if n
@@ -2768,7 +2767,7 @@
       ;;  Mail Sending                                           ;;
       ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
-      ;; Mail-sending window is implemented in sendr.ss. This is
+      ;; Mail-sending window is implemented in sendr.rkt. This is
       ;;  the set-up for opening such a window.
       
       (define my-address 
diff --git a/collects/sirmail/sendr.rkt b/collects/sirmail/sendr.rkt
index 18229c4ad0..34784f6b78 100644
--- a/collects/sirmail/sendr.rkt
+++ b/collects/sirmail/sendr.rkt
@@ -1,4 +1,3 @@
-
 ;; This module implements the mail-composing window. The `new-mailer'
 ;;  function creates a compose-window instance.
 
@@ -7,22 +6,22 @@
            scheme/unit
            scheme/class
            scheme/string
-	   mred/mred-sig
+           mred/mred-sig
            framework)
 
   (require scheme/file
-	   mzlib/process
-	   openssl/mzssl)
+           mzlib/process
+           openssl/mzssl)
 
-  (require "sirmails.ss"
-	   "pref.ss"
-           "spell.ss")
+  (require "sirmails.rkt"
+           "pref.rkt"
+           "spell.rkt")
 
   (require net/imap-sig
-	   net/smtp-sig
-	   net/head-sig
-	   net/base64-sig
-	   net/qp-sig)
+           net/smtp-sig
+           net/head-sig
+           net/base64-sig
+           net/qp-sig)
 
   (require mrlib/hierlist/hierlist-sig)
 
@@ -130,7 +129,7 @@
         #:mutable)
 
       ;; Create a message with enclosures.
-      ;;  `header' is a message header created with the head.ss library
+      ;;  `header' is a message header created with the head.rkt library
       ;;  `body-lines' is a list of strings and byte strings
       ;;  `enclosures' is a list of `enclosure' structs
       (define (enclose header body-lines enclosures)
diff --git a/collects/sirmail/sirmail.rkt b/collects/sirmail/sirmail.rkt
index 76653173aa..f957bb988c 100644
--- a/collects/sirmail/sirmail.rkt
+++ b/collects/sirmail/sirmail.rkt
@@ -3,31 +3,31 @@
 
 (module sirmail mzscheme
   (require mzlib/unit
-	   mzlib/class
-	   mred/mred-sig
-	   mred
+           mzlib/class
+           mred/mred-sig
+           mred
            framework
-	   mzlib/list)
+           mzlib/list)
 
-  (require "sirmails.ss"
-	   "pref.ss"
-	   "sirmailr.ss")
+  (require "sirmails.rkt"
+           "pref.rkt"
+           "sirmailr.rkt")
 
   (require net/imap-sig
-	   net/smtp-sig
-	   net/head-sig
-	   net/base64-sig
-	   net/mime-sig
-	   net/qp-sig
-	   net/imap
-	   net/smtp
-	   net/head
-	   net/base64
-	   net/mime
-	   net/qp)
+           net/smtp-sig
+           net/head-sig
+           net/base64-sig
+           net/mime-sig
+           net/qp-sig
+           net/imap
+           net/smtp
+           net/head
+           net/base64
+           net/mime
+           net/qp)
 
   (require mrlib/hierlist/hierlist-sig
-	   mrlib/hierlist)
+           mrlib/hierlist)
 
   ;; For testing purposes, cause GC accounting to be
   ;;  enabled:
@@ -100,8 +100,8 @@
 
   ;; There's only one Folders window ----------------------------------------
   
-  (require "optionr.ss"
-	   "folderr.ss")
+  (require "optionr.rkt"
+           "folderr.rkt")
 
   (define folders-window #f)
   (define folders-lock (make-semaphore 1))
diff --git a/collects/sirmail/sirmailr.rkt b/collects/sirmail/sirmailr.rkt
index 594c5637e6..a0058cf3ca 100644
--- a/collects/sirmail/sirmailr.rkt
+++ b/collects/sirmail/sirmailr.rkt
@@ -1,9 +1,8 @@
-
 (module sirmailr mzscheme
   (require mzlib/unit
-	   mred/mred-sig)
+           mred/mred-sig)
 
-  (require "sirmails.ss")
+  (require "sirmails.rkt")
 
   (require net/imap-sig
            net/smtp-sig
@@ -14,13 +13,13 @@
   
   (require mrlib/hierlist/hierlist-sig)
   
-  (require "utilr.ss"
-           "optionr.ss"
-           "readr.ss"
-           "sendr.ss")
+  (require "utilr.rkt"
+           "optionr.rkt"
+           "readr.rkt"
+           "sendr.rkt")
 
   ;; The sirmail@ unit implements a single reader window. See
-  ;; "sirmail.ss" for its use: 
+  ;; "sirmail.rkt" for its use: 
   (provide sirmail@)
   (define-compound-unit/infer sirmail@
     (import (ENV : sirmail:environment^)
diff --git a/collects/sirmail/utilr.rkt b/collects/sirmail/utilr.rkt
index fe1f58f1ec..0ff7bf25a3 100644
--- a/collects/sirmail/utilr.rkt
+++ b/collects/sirmail/utilr.rkt
@@ -1,15 +1,14 @@
-
 (module utilr mzscheme
   (require mzlib/unit
-	   mzlib/class
-	   mred/mred-sig
-	   net/qp-sig
-	   net/base64-sig
-	   (prefix unihead: net/unihead)
-	   mzlib/etc
-	   mzlib/string)
+           mzlib/class
+           mred/mred-sig
+           net/qp-sig
+           net/base64-sig
+           (prefix unihead: net/unihead)
+           mzlib/etc
+           mzlib/string)
 
-  (require "sirmails.ss")
+  (require "sirmails.rkt")
 
   (provide util@)
   (define-unit util@
diff --git a/collects/slatex/info.rkt b/collects/slatex/info.rkt
index 9d0c6066ae..49fa6c4c14 100644
--- a/collects/slatex/info.rkt
+++ b/collects/slatex/info.rkt
@@ -2,9 +2,9 @@
 
 (define scribblings '(("slatex-wrap.scrbl" () (tool-library))))
 
-;; (define tools (list (list "slatex-lang.ss")))
+;; (define tools (list (list "slatex-lang.rkt")))
 ;; (define tool-names (list "SLaTeX Language"))
 
 (define mzscheme-launcher-names '("SLaTeX" "PDF SLaTeX"))
-(define mzscheme-launcher-libraries '("slatex-launcher.ss"
-                                      "pdf-slatex-launcher.ss"))
+(define mzscheme-launcher-libraries '("slatex-launcher.rkt"
+                                      "pdf-slatex-launcher.rkt"))
diff --git a/collects/slatex/pdf-slatex-launcher.rkt b/collects/slatex/pdf-slatex-launcher.rkt
index 30b7464018..aa41f1e20b 100644
--- a/collects/slatex/pdf-slatex-launcher.rkt
+++ b/collects/slatex/pdf-slatex-launcher.rkt
@@ -1,6 +1,5 @@
-
 (module pdf-slatex-launcher mzscheme
-  (require "slatex-wrapper.ss"
+  (require "slatex-wrapper.rkt"
            scheme/cmdline)
 
   (define argv (current-command-line-arguments))
diff --git a/collects/slatex/slatex-launcher.rkt b/collects/slatex/slatex-launcher.rkt
index e487e0c316..47c2c0f01f 100644
--- a/collects/slatex/slatex-launcher.rkt
+++ b/collects/slatex/slatex-launcher.rkt
@@ -1,6 +1,5 @@
-
 (module slatex-launcher scheme/base
-  (require "slatex-wrapper.ss"
+  (require "slatex-wrapper.rkt"
            scheme/cmdline)
 
   (define argv (current-command-line-arguments))
diff --git a/collects/slatex/slatex-wrapper.rkt b/collects/slatex/slatex-wrapper.rkt
index d41c419e11..0076b21ebe 100644
--- a/collects/slatex/slatex-wrapper.rkt
+++ b/collects/slatex/slatex-wrapper.rkt
@@ -1,11 +1,10 @@
-
 (module slatex-wrapper scheme/base
   (require mzlib/file
            scheme/contract
-	   mzlib/process
-	   mzlib/sendevent
+           mzlib/process
+           mzlib/sendevent
            scheme/runtime-path
-           "private/slatex.ss")
+           "private/slatex.rkt")
   
   (define-runtime-path here ".")
 
diff --git a/collects/slideshow/base.rkt b/collects/slideshow/base.rkt
index 439120261e..cd1a4206b0 100644
--- a/collects/slideshow/base.rkt
+++ b/collects/slideshow/base.rkt
@@ -1,8 +1,7 @@
-
 (module base scheme/base
-  (require "slide.ss"
+  (require "slide.rkt"
            scheme/gui/base
-           (only-in "core.ss"
+           (only-in "core.rkt"
                     sliderec?
                     just-a-comment?))
 
diff --git a/collects/slideshow/cmdline.rkt b/collects/slideshow/cmdline.rkt
index fe6a77d54e..1c6a29bd28 100644
--- a/collects/slideshow/cmdline.rkt
+++ b/collects/slideshow/cmdline.rkt
@@ -1,17 +1,16 @@
-
 (module cmdline mzscheme
   (require mzlib/class
            mzlib/unit
-	   mzlib/file
-	   mzlib/etc
-	   mzlib/contract
-	   mred
-	   mzlib/cmdline
-	   texpict/mrpict
-	   texpict/utils
-	   mzlib/math
-	   "sig.ss"
-	   (prefix start: "start-param.ss"))
+           mzlib/file
+           mzlib/etc
+           mzlib/contract
+           mred
+           mzlib/cmdline
+           texpict/mrpict
+           texpict/utils
+           mzlib/math
+           "sig.rkt"
+           (prefix start: "start-param.rkt"))
 
   (provide cmdline@)
 
diff --git a/collects/slideshow/code.rkt b/collects/slideshow/code.rkt
index c23091d305..816a44fb0a 100644
--- a/collects/slideshow/code.rkt
+++ b/collects/slideshow/code.rkt
@@ -1,7 +1,6 @@
-
-(module code "slideshow.ss"
+(module code "slideshow.rkt"
   (require texpict/code
-	   mzlib/unit)
+           mzlib/unit)
   (require-for-syntax syntax/to-string
                       mzlib/list)
 
diff --git a/collects/slideshow/info.rkt b/collects/slideshow/info.rkt
index 3eb85ee9b5..03613f11ad 100644
--- a/collects/slideshow/info.rkt
+++ b/collects/slideshow/info.rkt
@@ -1,8 +1,8 @@
 #lang setup/infotab
 
-(define tools (list '("tool.ss")))
+(define tools (list '("tool.rkt")))
 (define tool-names (list "Slideshow"))
 (define tool-icons (list (list "slideshow.png" "slideshow")))
-(define mred-launcher-libraries (list "start.ss"))
+(define mred-launcher-libraries (list "start.rkt"))
 (define mred-launcher-names (list "Slideshow"))
-(define compile-omit-paths '("initial-ones.ss" "pict-snipclass.ss" "examples"))
+(define compile-omit-paths '("initial-ones.rkt" "pict-snipclass.rkt" "examples"))
diff --git a/collects/slideshow/main.rkt b/collects/slideshow/main.rkt
index fc4f4381a6..46094ca766 100644
--- a/collects/slideshow/main.rkt
+++ b/collects/slideshow/main.rkt
@@ -1,10 +1,7 @@
-
 (module main racket
-  (require "base.ss"
-           "pict.ss")
+  (require "base.rkt"
+           "pict.rkt")
   (provide (except-out (all-from-out racket
-                                     "base.ss"
-                                     "pict.ss")
+                                     "base.rkt"
+                                     "pict.rkt")
                        printable<%>)))
-
-
diff --git a/collects/slideshow/param.rkt b/collects/slideshow/param.rkt
index 2c3b9d320f..9e364a0b1a 100644
--- a/collects/slideshow/param.rkt
+++ b/collects/slideshow/param.rkt
@@ -1,9 +1,8 @@
-
 (module param mzscheme
   (require mzlib/unit
-	   "sig.ss"
-	   "cmdline.ss"
-	   "viewer.ss")
+           "sig.rkt"
+           "cmdline.rkt"
+           "viewer.rkt")
 
   (provide current-slideshow-linker)
 
diff --git a/collects/slideshow/pict-snipclass.rkt b/collects/slideshow/pict-snipclass.rkt
index 61606d7ad2..ff8b1ba220 100644
--- a/collects/slideshow/pict-snipclass.rkt
+++ b/collects/slideshow/pict-snipclass.rkt
@@ -3,7 +3,7 @@
            mred)
   
   (provide snip-class)
-  (require "private/pict-box-lib.ss")
+  (require "private/pict-box-lib.rkt")
 
   (define pict-snip%
     (class* editor-snip% (readable-snip<%>)
diff --git a/collects/slideshow/private/pict-box-lib.rkt b/collects/slideshow/private/pict-box-lib.rkt
index 21d67bcde2..48f45f8c35 100644
--- a/collects/slideshow/private/pict-box-lib.rkt
+++ b/collects/slideshow/private/pict-box-lib.rkt
@@ -2,7 +2,7 @@
   (require mred
            mzlib/class
            texpict/mrpict
-           "image-snipr.ss")
+           "image-snipr.rkt")
   
   (provide get-snp/poss
            build-lib-pict-stx
diff --git a/collects/slideshow/run.rkt b/collects/slideshow/run.rkt
index eea4aabacc..c9c573f25d 100644
--- a/collects/slideshow/run.rkt
+++ b/collects/slideshow/run.rkt
@@ -1,2 +1,2 @@
-(module run "slideshow.ss"
-  (provide (all-from "slideshow.ss")))
+(module run "slideshow.rkt"
+  (provide (all-from "slideshow.rkt")))
diff --git a/collects/slideshow/slide.rkt b/collects/slideshow/slide.rkt
index 449e216cd2..5f74193487 100644
--- a/collects/slideshow/slide.rkt
+++ b/collects/slideshow/slide.rkt
@@ -1,22 +1,22 @@
 (module slide racket/base
   (require racket/unit
-	   racket/contract
-	   texpict/mrpict
-	   texpict/utils
-	   "sig.ss"
-	   "core.ss"
-	   "private/utils.ss"
-	   "param.ss")
+           racket/contract
+           texpict/mrpict
+           texpict/utils
+           "sig.rkt"
+           "core.rkt"
+           "private/utils.rkt"
+           "param.rkt")
 
   ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;;       Link Config and Viewer with Core        ;;
   ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
   ;; The actual config and viewer units are determined by a parameter
-  ;;  in "param.ss". This somewhat strange technqiue allows the units
+  ;;  in "param.rkt". This somewhat strange technqiue allows the units
   ;;  to be changed as this module is loaded in a new namespace; see
-  ;;  "slides-to-picts.ss". Such namespace games are not necessary if
-  ;;  talks are written as units and linked to the core.ss unit.
+  ;;  "slides-to-picts.rkt". Such namespace games are not necessary if
+  ;;  talks are written as units and linked to the core.rkt unit.
 
   (define-values/invoke-unit ((current-slideshow-linker) core@)
     (import)
diff --git a/collects/slideshow/slides-to-picts.rkt b/collects/slideshow/slides-to-picts.rkt
index f4b1e221a3..acc1ae9ef1 100644
--- a/collects/slideshow/slides-to-picts.rkt
+++ b/collects/slideshow/slides-to-picts.rkt
@@ -1,11 +1,10 @@
-
 (module slides-to-picts scheme/base
   (require racket/draw
            scheme/class
            scheme/unit
-	   "sig.ss"
-	   "param.ss"
-	   "core.ss"
+           "sig.rkt"
+           "param.rkt"
+           "core.rkt"
            texpict/mrpict)
 
   (provide get-slides-as-picts)
diff --git a/collects/slideshow/start.rkt b/collects/slideshow/start.rkt
index fbb50dfdfe..250e69653b 100644
--- a/collects/slideshow/start.rkt
+++ b/collects/slideshow/start.rkt
@@ -1,8 +1,7 @@
-
-(module start "slideshow.ss"
-  (require "start-param.ss"
+(module start "slideshow.rkt"
+  (require "start-param.rkt"
            planet/config
-	   mred
+           mred
            mzlib/class)
 
   ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -93,7 +92,7 @@
 			     (retract-most-recent-slide)
 			     (load-content
 			      (build-path (collection-path "slideshow")
-					  "tutorial-show.ss")))))
+                                          "tutorial-show.rkt")))))
 	 (page-para* (link "Open File..."
 			   (lambda ()
 			     (let ([file (get-file)])
diff --git a/collects/slideshow/tool.rkt b/collects/slideshow/tool.rkt
index 31fbd37d1b..9554488580 100644
--- a/collects/slideshow/tool.rkt
+++ b/collects/slideshow/tool.rkt
@@ -25,8 +25,8 @@ pict snip :
            texpict/mrpict
            texpict/pict-value-snip
            mzlib/list
-           "private/pict-box-lib.ss"
-           "private/image-snipr.ss")
+           "private/pict-box-lib.rkt"
+           "private/image-snipr.rkt")
 
   (provide tool@
            get-snp/poss
diff --git a/collects/slideshow/tutorial-show.rkt b/collects/slideshow/tutorial-show.rkt
index af8ac23332..5b5cf59dbd 100644
--- a/collects/slideshow/tutorial-show.rkt
+++ b/collects/slideshow/tutorial-show.rkt
@@ -6,7 +6,7 @@
 ;; The first few slides are not to be read
 ;; until you have seen the rest of the tutorial,
 ;; so we put them in a separate file
-(require "initial-ones.ss")
+(require "initial-ones.rkt")
 (do-initial-slides)
 
 ;; The rest is meant for reading, as you view the slides
@@ -805,7 +805,7 @@
  #:title "Printing"
  (para "To export a set of slides as PostScript, "
             "use the" (tt "slideshow") "command-line program:")
- (tt "slideshow --print mytalk.ss")
+ (tt "slideshow --print mytalk.rkt")
  (blank)
  (para "Slideshow steps through slides while producing PostScript pages")
  (para "The slides will look bad on the screen --- because"
@@ -816,11 +816,11 @@
  #:title "Condensing"
  (para "Often, it makes sense to eliminate" (code 'step)
             "staging when printing slides:")
- (tt "slideshow --print --condense mytalk.ss")
+ (tt "slideshow --print --condense mytalk.rkt")
  (blank)
  'next
  (para "You can also condense without printing")
- (tt "slideshow --condense mytalk.ss")
+ (tt "slideshow --condense mytalk.rkt")
  'next
  (blank)
  (para "For example, in condensed form, this slide appears"
diff --git a/collects/slideshow/viewer.rkt b/collects/slideshow/viewer.rkt
index f9f8fa29ba..dea1bc357b 100644
--- a/collects/slideshow/viewer.rkt
+++ b/collects/slideshow/viewer.rkt
@@ -11,9 +11,9 @@
 	   texpict/utils
 	   scheme/math
 	   mrlib/include-bitmap
-	   "sig.ss"
-	   "core.ss"
-	   "private/utils.ss")
+	   "sig.rkt"
+	   "core.rkt"
+	   "private/utils.rkt")
 
   (provide viewer@)
 
diff --git a/collects/srfi/1/alist.rkt b/collects/srfi/1/alist.rkt
index f3874f1069..1a85afe980 100644
--- a/collects/srfi/1/alist.rkt
+++ b/collects/srfi/1/alist.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <alist.ss> ---- Association list functions
+;;; <alist.rkt> ---- Association list functions
 ;;; Time-stamp: <02/03/01 13:56:33 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -25,7 +25,7 @@
 
 #lang scheme/base
 
-(require (only-in "search.ss" find))
+(require (only-in "search.rkt" find))
 
 (provide (rename-out [my-assoc assoc])
          alist-cons
@@ -50,4 +50,4 @@
 (define (alist-delete! key alist [= equal?])
   (filter! (lambda (elt) (not (= key (car elt)))) alist))
 
-;;; alist.ss ends here
+;;; alist.rkt ends here
diff --git a/collects/srfi/1/cons.rkt b/collects/srfi/1/cons.rkt
index 4053e03df0..e598b1a5f1 100644
--- a/collects/srfi/1/cons.rkt
+++ b/collects/srfi/1/cons.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <cons.ss> ---- List constructors
+;;; <cons.rkt> ---- List constructors
 ;;; Time-stamp: <02/02/27 12:19:59 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -25,7 +25,7 @@
 
 #lang scheme/base
 
-(require srfi/optional "selector.ss"
+(require srfi/optional "selector.rkt"
          (only-in scheme/list [make-list make-list*]))
 
 (provide xcons
@@ -90,4 +90,4 @@
     (if (= n count) '()
         (cons (+ start (* n step)) (loop (add1 n))))))
 
-;;; cons.ss ends here
+;;; cons.rkt ends here
diff --git a/collects/srfi/1/delete.rkt b/collects/srfi/1/delete.rkt
index 978b398ddc..014f13bae1 100644
--- a/collects/srfi/1/delete.rkt
+++ b/collects/srfi/1/delete.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <delete.ss> ---- List deletion functions
+;;; <delete.rkt> ---- List deletion functions
 ;;; Time-stamp: <02/03/01 07:26:12 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -26,7 +26,7 @@
 
 #lang scheme/base
 
-(require srfi/optional "predicate.ss")
+(require srfi/optional "predicate.rkt")
 
 (provide delete (rename-out [delete delete!])
          delete-duplicates (rename-out [delete-duplicates delete-duplicates!]))
@@ -66,4 +66,4 @@
                (new-tail (recur (delete! x tail elt=))))
           (if (eq? tail new-tail) lis (cons x new-tail))))))
 
-;;; delete.ss ends here
+;;; delete.rkt ends here
diff --git a/collects/srfi/1/filter.rkt b/collects/srfi/1/filter.rkt
index 94d868e18c..c6252aec63 100644
--- a/collects/srfi/1/filter.rkt
+++ b/collects/srfi/1/filter.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <filter.ss> ---- List filtering and partitioning functions
+;;; <filter.rkt> ---- List filtering and partitioning functions
 ;;; Time-stamp: <02/03/01 07:26:43 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -25,7 +25,7 @@
 
 #lang scheme/base
 
-(require srfi/optional "predicate.ss")
+(require srfi/optional "predicate.rkt")
 
 (provide filter (rename-out [filter filter!])
          (rename-out [my-filter filter-with-sharing]) ; see comment below
@@ -38,10 +38,10 @@
 ;; disorder the elements of their argument.
 
 ;; The following version of filter is not really needed, so we reprovide the
-;; one from "scheme/private/list.ss".  That one does not keep the longest tail,
+;; one from "scheme/private/list.rkt".  That one does not keep the longest tail,
 ;; but running a few benchmarks (on v3.99.0.18) shows that on long lists the
 ;; code below is slower, and on short lists it is a little faster, but not by
-;; much.  However, seems that "lset.ss" relies on tail-sharing, so it is
+;; much.  However, seems that "lset.rkt" relies on tail-sharing, so it is
 ;; provided under an alternative name above.
 
 ;; This FILTER shares the longest tail of L that has no deleted
@@ -166,4 +166,4 @@
 #; ; lists are immutable
 (define (remove! pred l) (filter! (lambda (x) (not (pred x))) l))
 
-;;; filter.ss ends here
+;;; filter.rkt ends here
diff --git a/collects/srfi/1/fold.rkt b/collects/srfi/1/fold.rkt
index 34fae4c8bb..4939b7f1b9 100644
--- a/collects/srfi/1/fold.rkt
+++ b/collects/srfi/1/fold.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <fold.ss> ---- List folds
+;;; <fold.rkt> ---- List folds
 ;;; Time-stamp: <02/02/28 12:02:38 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -26,9 +26,9 @@
 #lang scheme/base
 
 (require srfi/optional
-         "predicate.ss"
-         "selector.ss"
-         "util.ss")
+         "predicate.rkt"
+         "selector.rkt"
+         "util.rkt")
 
 (provide (rename-out [my-map map])
          (rename-out [my-for-each for-each])
@@ -248,4 +248,4 @@
         (f (car lis))             ; Do head first,
         (recur (cdr lis))))))
 
-;;; fold.ss ends here
+;;; fold.rkt ends here
diff --git a/collects/srfi/1/list.rkt b/collects/srfi/1/list.rkt
index d00d602b7d..d648d68af5 100644
--- a/collects/srfi/1/list.rkt
+++ b/collects/srfi/1/list.rkt
@@ -211,30 +211,30 @@
 ;;;
 ;;; The SRFI discussion record contains more discussion on this topic.
 
-;; JBC, 2003-10-20: some of the names provided by list.ss are prefixed
-;; with an s: to avoid colliding with mzscheme.  The wrapper 1.ss
+;; JBC, 2003-10-20: some of the names provided by list.rkt are prefixed
+;; with an s: to avoid colliding with mzscheme.  The wrapper 1.rkt
 ;; changes their names back to the non-prefixed form.
 
 #lang scheme/base
 
-(require "cons.ss"
-         "selector.ss"
-         "predicate.ss"
-         "misc.ss"
-         (rename-in "fold.ss" [map s:map] [for-each s:for-each])
-         (rename-in "search.ss" [member s:member])
-         (rename-in "filter.ss" [remove s:remove])
-         "delete.ss"
-         (rename-in "alist.ss" [assoc s:assoc])
-         "lset.ss")
+(require "cons.rkt"
+         "selector.rkt"
+         "predicate.rkt"
+         "misc.rkt"
+         (rename-in "fold.rkt" [map s:map] [for-each s:for-each])
+         (rename-in "search.rkt" [member s:member])
+         (rename-in "filter.rkt" [remove s:remove])
+         "delete.rkt"
+         (rename-in "alist.rkt" [assoc s:assoc])
+         "lset.rkt")
 
-(provide (all-from-out "cons.ss")
-         (all-from-out "selector.ss")
-         (all-from-out "predicate.ss")
-         (all-from-out "misc.ss")
-         (all-from-out "fold.ss")
-         (all-from-out "search.ss")
-         (all-from-out "filter.ss")
-         (all-from-out "delete.ss")
-         (all-from-out "alist.ss")
-         (all-from-out "lset.ss"))
+(provide (all-from-out "cons.rkt")
+         (all-from-out "selector.rkt")
+         (all-from-out "predicate.rkt")
+         (all-from-out "misc.rkt")
+         (all-from-out "fold.rkt")
+         (all-from-out "search.rkt")
+         (all-from-out "filter.rkt")
+         (all-from-out "delete.rkt")
+         (all-from-out "alist.rkt")
+         (all-from-out "lset.rkt"))
diff --git a/collects/srfi/1/lset.rkt b/collects/srfi/1/lset.rkt
index 3c825c4799..3495d36dbe 100644
--- a/collects/srfi/1/lset.rkt
+++ b/collects/srfi/1/lset.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <lset.ss> ---- Lists as Sets
+;;; <lset.rkt> ---- Lists as Sets
 ;;; Time-stamp: <03/03/13 16:20:56 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -26,11 +26,11 @@
 #lang scheme/base
 
 (require srfi/optional
-         (rename-in "search.ss" [member s:member])
-         (except-in "fold.ss" map for-each)
-         "delete.ss"
-         "predicate.ss"
-         (only-in "filter.ss" [filter-with-sharing s:filter] partition))
+         (rename-in "search.rkt" [member s:member])
+         (except-in "fold.rkt" map for-each)
+         "delete.rkt"
+         "predicate.rkt"
+         (only-in "filter.rkt" [filter-with-sharing s:filter] partition))
 
 (provide lset<=
          lset=
@@ -215,4 +215,4 @@
                                       lists)))
                           lis1))))
 
-;;; lset.ss ends here
+;;; lset.rkt ends here
diff --git a/collects/srfi/1/misc.rkt b/collects/srfi/1/misc.rkt
index 252829f9d1..052a79677d 100644
--- a/collects/srfi/1/misc.rkt
+++ b/collects/srfi/1/misc.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <misc.ss> ---- Miscellaneous list procedures
+;;; <misc.rkt> ---- Miscellaneous list procedures
 ;;; Time-stamp: <02/03/01 13:52:22 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -26,11 +26,11 @@
 #lang scheme/base
 
 (require srfi/optional
-         "predicate.ss"
-         "selector.ss"
-         "util.ss"
-         (only-in "fold.ss" reduce-right)
-         (rename-in "fold.ss" [map s:map] [for-each s:for-each])
+         "predicate.rkt"
+         "selector.rkt"
+         "util.rkt"
+         (only-in "fold.rkt" reduce-right)
+         (rename-in "fold.rkt" [map s:map] [for-each s:for-each])
          (only-in scheme/list count append*))
 
 (provide length+
@@ -175,4 +175,4 @@
           (set-cdr! lis ans)
           (lp tail lis)))))
 
-;;; misc.ss ends here
+;;; misc.rkt ends here
diff --git a/collects/srfi/1/predicate.rkt b/collects/srfi/1/predicate.rkt
index 0f08c43d9f..6dbc70f8dc 100644
--- a/collects/srfi/1/predicate.rkt
+++ b/collects/srfi/1/predicate.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <predicate.ss> ---- List Predicates
+;;; <predicate.rkt> ---- List Predicates
 ;;; Time-stamp: <02/02/27 12:57:15 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -104,4 +104,4 @@
                          (= (car la) (car lb))
                          (lp2 (cdr la) (cdr lb)))))))))))
 
-;;; predicate.ss ends here
+;;; predicate.rkt ends here
diff --git a/collects/srfi/1/search.rkt b/collects/srfi/1/search.rkt
index 1b051bba4c..8040e069e8 100644
--- a/collects/srfi/1/search.rkt
+++ b/collects/srfi/1/search.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 
 ;;;
-;;; <search.ss> ---- List searching functions
+;;; <search.rkt> ---- List searching functions
 ;;; Time-stamp: <02/02/28 12:11:01 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -28,8 +28,8 @@
 
 
 (require srfi/optional
-         "predicate.ss"
-         "util.ss")
+         "predicate.rkt"
+         "util.rkt")
 
 (provide (rename-out [my-member member])
          find
@@ -173,4 +173,4 @@
       (and (not (null-list? lis))
            (if (pred (car lis)) n (lp (cdr lis) (+ n 1)))))))
 
-;;; search.ss ends here
+;;; search.rkt ends here
diff --git a/collects/srfi/1/selector.rkt b/collects/srfi/1/selector.rkt
index 2dac3e071d..90570d8817 100644
--- a/collects/srfi/1/selector.rkt
+++ b/collects/srfi/1/selector.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <selector.ss> ---- List selectors
+;;; <selector.rkt> ---- List selectors
 ;;; Time-stamp: <02/02/27 12:49:44 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -139,4 +139,4 @@
     (let ((tail (cdr lis)))
       (if (pair? tail) (lp tail) lis))))
 
-;;; selector.ss ends here
+;;; selector.rkt ends here
diff --git a/collects/srfi/1/util.rkt b/collects/srfi/1/util.rkt
index ec08fbe562..0499c23ea4 100644
--- a/collects/srfi/1/util.rkt
+++ b/collects/srfi/1/util.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <util.ss> ---- Utility functions
+;;; <util.rkt> ---- Utility functions
 ;;; Time-stamp: <02/02/28 12:05:00 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -25,8 +25,8 @@
 
 #lang scheme/base
 
-(require "predicate.ss"
-         "selector.ss")
+(require "predicate.rkt"
+         "selector.rkt")
 
 (provide %cdrs
          %cars+
@@ -105,4 +105,4 @@
         (values (cons a cars) (cons d cdrs)))
       (values '() '()))))
 
-;;; util.ss ends here
+;;; util.rkt ends here
diff --git a/collects/srfi/13/string.rkt b/collects/srfi/13/string.rkt
index 16a6ad7c27..40cdb5e600 100644
--- a/collects/srfi/13/string.rkt
+++ b/collects/srfi/13/string.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <string.ss> ---- SRFI 13 port to PLT Scheme
+;;; <string.rkt> ---- SRFI 13 port to PLT Scheme
 ;;; Revised by Chongkai Zhu, based on the orgianl port
 ;;;
 ;;; Here is the copyright notice, and licence from the original source:
@@ -1876,4 +1876,4 @@
 
             (else "")))))             ; Special-cased for infix grammar.
 
-;; string.ss ends here
+;; string.rkt ends here
diff --git a/collects/srfi/14/char-set.rkt b/collects/srfi/14/char-set.rkt
index fa62a85b3b..baa1930d4f 100644
--- a/collects/srfi/14/char-set.rkt
+++ b/collects/srfi/14/char-set.rkt
@@ -1,13 +1,12 @@
-
 ;; Since Matthew implemented this module, tests are in
-;;  plt/collects/tests/mzscheme/char-set.ss.
+;;  collects/tests/mzscheme/char-set.rkt.
 ;; Since Mike Sperber looked carefully at this module,
 ;;  the code and tests are a lot better than they would be.
 
 (module char-set mzscheme
   (require mzlib/integer-set
-	   (all-except mzlib/contract union)
-	   (rename mzlib/contract union/c union))
+           (all-except mzlib/contract union)
+           (rename mzlib/contract union/c union))
 
   ;; Data defn ----------------------------------------
     
diff --git a/collects/srfi/19/time.rkt b/collects/srfi/19/time.rkt
index 37146a1187..a37fac7036 100644
--- a/collects/srfi/19/time.rkt
+++ b/collects/srfi/19/time.rkt
@@ -49,7 +49,7 @@
 ;; is copied below.
 ;;
 ; srfi-8: receive
-;(require-library "synrule.ss") -- PLT doesn't like DEFINE-SYNTAX. 
+;(require-library "synrule.rkt") -- PLT doesn't like DEFINE-SYNTAX. 
 
 ;(define-syntax receive
 ;  (syntax-rules ()
diff --git a/collects/srfi/2/and-let.rkt b/collects/srfi/2/and-let.rkt
index bebc5a792c..90938fd429 100644
--- a/collects/srfi/2/and-let.rkt
+++ b/collects/srfi/2/and-let.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <land.ss> ---- SRFI 2 port to PLT Scheme: LAND*, a generalized AND.
+;;; <land.rkt> ---- SRFI 2 port to PLT Scheme: LAND*, a generalized AND.
 ;;; Time-stamp: <02/04/30 08:05:27 solsona>
 ;;;
 ;;; Usually, I would add a copyright notice, and the announce that
@@ -139,7 +139,7 @@
 ; The first "failure" triggers the guard and aborts the rest of the
 ; sequence (which presumably would not make any sense to execute anyway).
 ;
-; $Id: and-let.ss,v 1.1 2003/02/25 01:49:25 solsona Exp $
+; $Id: and-let.rkt,v 1.1 2003/02/25 01:49:25 solsona Exp $
 
 ;;; See: http://srfi.schemers.org for more information on SRFIs.
 
@@ -201,4 +201,4 @@
 
   )
 
-;;; land.ss ends here
+;;; land.rkt ends here
diff --git a/collects/srfi/26/cut.rkt b/collects/srfi/26/cut.rkt
index 16f344d16f..f8c1af69bc 100644
--- a/collects/srfi/26/cut.rkt
+++ b/collects/srfi/26/cut.rkt
@@ -1,4 +1,4 @@
-;;; cut.ss
+;;; cut.rkt
 
 ; This file reimplements srfi-26 for PLT.
 ; The reimplementation provides better error messages.
diff --git a/collects/srfi/41/derived.rkt b/collects/srfi/41/derived.rkt
index 0381a60214..595623b19f 100644
--- a/collects/srfi/41/derived.rkt
+++ b/collects/srfi/41/derived.rkt
@@ -25,7 +25,7 @@
  stream-of stream-range stream-ref stream-reverse stream-scan stream-take
  stream-take-while stream-unfold stream-unfolds stream-zip)
 
-(require "primitive.ss")
+(require "primitive.rkt")
 
 (define-syntax define-stream
  (syntax-rules ()
diff --git a/collects/srfi/41/streams.rkt b/collects/srfi/41/streams.rkt
index 5a8eaa7215..0d9d3dd8bd 100644
--- a/collects/srfi/41/streams.rkt
+++ b/collects/srfi/41/streams.rkt
@@ -26,4 +26,4 @@
           stream-of stream-range stream-ref stream-reverse stream-scan stream-take
           stream-take-while stream-unfold stream-unfolds stream-zip)
 
-  (require "primitive.ss" "derived.ss")
+  (require "primitive.rkt" "derived.rkt")
diff --git a/collects/srfi/5/let.rkt b/collects/srfi/5/let.rkt
index 6ed4bd261a..cd346163f7 100644
--- a/collects/srfi/5/let.rkt
+++ b/collects/srfi/5/let.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <let.ss> ---- SRFI 5 A compatible let form with signatures and rest arguments
+;;; <let.rkt> ---- SRFI 5 A compatible let form with signatures and rest arguments
 ;;; Time-stamp: <03/04/08 09:56:06 solsona>
 ;;;
 ;;; Usually, I would add a copyright notice, and the announce that
diff --git a/collects/srfi/57/records.rkt b/collects/srfi/57/records.rkt
index 58199e4c83..fe3ff2852a 100644
--- a/collects/srfi/57/records.rkt
+++ b/collects/srfi/57/records.rkt
@@ -13,7 +13,7 @@
   (require            (prefix s9: srfi/9))
   (require-for-syntax (prefix s1: srfi/1))
 
-  (require-for-syntax "registry.ss")
+  (require-for-syntax "registry.rkt")
 
   (define-syntax define-record-type
     (syntax-rules ()
diff --git a/collects/srfi/7/program.rkt b/collects/srfi/7/program.rkt
index 289fe099f5..be6b075a97 100644
--- a/collects/srfi/7/program.rkt
+++ b/collects/srfi/7/program.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <program.ss> ---- SRFI-7 program
+;;; <program.rkt> ---- SRFI-7 program
 ;;; based on MJ Ray's code for SRFI 0
 
 (module program mzscheme
@@ -126,4 +126,4 @@
 	       (feature-cond rest ...)
 	       more ...))))))))
 
-;;; program.ss ends here
+;;; program.rkt ends here
diff --git a/collects/srfi/8/receive.rkt b/collects/srfi/8/receive.rkt
index 969c250033..17c0ef7fe0 100644
--- a/collects/srfi/8/receive.rkt
+++ b/collects/srfi/8/receive.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <receive.ss> ---- SRFI 8 Binding to Multiple Values port to PLT Scheme
+;;; <receive.rkt> ---- SRFI 8 Binding to Multiple Values port to PLT Scheme
 ;;; Time-stamp: <02/05/10 12:22:37 solsona>
 ;;;
 ;;; Usually, I would add a copyright notice, and the announce that
diff --git a/collects/srfi/features.rkt b/collects/srfi/features.rkt
index 7aa3029c2a..093ee952c0 100644
--- a/collects/srfi/features.rkt
+++ b/collects/srfi/features.rkt
@@ -9,7 +9,7 @@
   (regexp-match? #rx"^srfi-[0-9]+$" (symbol->string id)))
 
 (define (srfi-id->filename srfi-id)
-  (regexp-replace #rx"^srfi-([0-9]+)$" (symbol->string srfi-id) "\\1/\\1.ss"))
+  (regexp-replace #rx"^srfi-([0-9]+)$" (symbol->string srfi-id) "\\1/\\1.rkt"))
 
 (define (srfi-id-present? srfi-id)
   (file-exists? (build-path (collection-path "srfi")
diff --git a/collects/srfi/optional.rkt b/collects/srfi/optional.rkt
index 16af7a4ede..7c0bd34dd3 100644
--- a/collects/srfi/optional.rkt
+++ b/collects/srfi/optional.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <optional.ss> ---- Let-optionals macros
+;;; <optional.rkt> ---- Let-optionals macros
 ;;; Time-stamp: <2011-02-02 11:44:21 dvanhorn>
 ;;;
 ;;; Usually, I would add a copyright notice, and the announce that
@@ -165,4 +165,4 @@
      (if (null? arg) (begin body ...)
          (error "Too many arguments in let-opt" arg))]))
 
-;; optional.ss ends here
+;; optional.rkt ends here
diff --git a/collects/srfi/provider.rkt b/collects/srfi/provider.rkt
index d7b79c90e3..ab802383c6 100644
--- a/collects/srfi/provider.rkt
+++ b/collects/srfi/provider.rkt
@@ -2,8 +2,8 @@
 
 (require (for-syntax scheme/base scheme/provide-transform))
 
-;; This is a utility for many srfi/N.ss files that simply reprovide stuff from
-;; some other file.  It is used as a module, for example, the "srfi/1.ss"
+;; This is a utility for many srfi/N.rkt files that simply reprovide stuff from
+;; some other file.  It is used as a module, for example, the "srfi/1.rkt"
 ;; loader has:
 ;;   #lang s-exp srfi/provider srfi/1/list #:unprefix s:
 ;; which makes it require `srfi/1/list', then reprovide everything from there,
diff --git a/collects/srpersist/main.rkt b/collects/srpersist/main.rkt
index a70f3985b6..fb12f63af8 100644
--- a/collects/srpersist/main.rkt
+++ b/collects/srpersist/main.rkt
@@ -1,4 +1,4 @@
 #lang scheme/base
 
-(require "srpersist.ss")
-(provide (all-from-out "srpersist.ss"))
+(require "srpersist.rkt")
+(provide (all-from-out "srpersist.rkt"))
diff --git a/collects/srpersist/private/sigs.rkt b/collects/srpersist/private/sigs.rkt
index ddfb1077bc..7aee9facd7 100644
--- a/collects/srpersist/private/sigs.rkt
+++ b/collects/srpersist/private/sigs.rkt
@@ -1,4 +1,4 @@
-;; sigs.ss for srpersist collection
+;; sigs.rkt for srpersist collection
 
 (module sigs mzscheme
 
diff --git a/collects/stepper/drracket-button.rkt b/collects/stepper/drracket-button.rkt
index 67842fecb9..0cc450fe04 100644
--- a/collects/stepper/drracket-button.rkt
+++ b/collects/stepper/drracket-button.rkt
@@ -1,6 +1,6 @@
 #lang scheme/base
 (require scheme/class string-constants/string-constant
-         (prefix-in x: "private/mred-extensions.ss"))
+         (prefix-in x: "private/mred-extensions.rkt"))
 (provide stepper-button-callback stepper-drracket-button)
 (define-local-member-name stepper-button-callback)
 
diff --git a/collects/stepper/info.rkt b/collects/stepper/info.rkt
index ae2a7d8351..81668d6d12 100644
--- a/collects/stepper/info.rkt
+++ b/collects/stepper/info.rkt
@@ -1,11 +1,9 @@
 #lang setup/infotab
 
-(define drracket-tools '(("stepper+xml-tool.ss")))
+(define drracket-tools '(("stepper+xml-tool.rkt")))
 
 (define drracket-tool-names (list "The Stepper"))
 
 (define drracket-tool-icons (list '("foot-up.png" "icons")))
 
-(define compile-omit-paths '("debugger-tool.ss"))
-
 (define scribblings '(("scribblings/stepper.scrbl")))
diff --git a/collects/stepper/private/annotate.rkt b/collects/stepper/private/annotate.rkt
index 6728e1a20a..c89692f35e 100644
--- a/collects/stepper/private/annotate.rkt
+++ b/collects/stepper/private/annotate.rkt
@@ -2,11 +2,11 @@
 
 (require (prefix-in kernel: syntax/kerncase)
          racket/contract
-         "marks.ss"
-         "shared.ss"
-         "my-macros.ss"
-         #;"xml-box.ss"
-         (prefix-in beginner-defined: "beginner-defined.ss")
+         "marks.rkt"
+         "shared.rkt"
+         "my-macros.rkt"
+         #;"xml-box.rkt"
+         (prefix-in beginner-defined: "beginner-defined.rkt")
          (for-syntax racket/base))
 
 (define-syntax (where stx)
@@ -199,7 +199,7 @@
            (stepper-syntax-property stx 'stepper-skip-completely #t)]
           
           ; wrapper on a local.  This is necessary because 
-          ; teach.ss expands local into a trivial let wrapping a bunch of
+          ; teach.rkt expands local into a trivial let wrapping a bunch of
           ; internal defines, and therefore the letrec-values on 
           ; which I want to hang the 'stepper-hint doesn't yet
           ; exist.  So we patch it up after expansion.  And we 
diff --git a/collects/stepper/private/display-break-stuff.rkt b/collects/stepper/private/display-break-stuff.rkt
index 39bb18504e..8942841922 100644
--- a/collects/stepper/private/display-break-stuff.rkt
+++ b/collects/stepper/private/display-break-stuff.rkt
@@ -1,6 +1,6 @@
 #lang racket
 
-(require mred mzlib/class "marks.ss")
+(require mred mzlib/class "marks.rkt")
 
 (provide display-break-stuff)
 
diff --git a/collects/stepper/private/lifting.rkt b/collects/stepper/private/lifting.rkt
index 4e01615766..4c23f5113d 100644
--- a/collects/stepper/private/lifting.rkt
+++ b/collects/stepper/private/lifting.rkt
@@ -1,8 +1,8 @@
 #lang racket
 
 (require (prefix-in kernel: syntax/kerncase)
-         "testing-shared.ss"
-         "shared.ss"
+         "testing-shared.rkt"
+         "shared.rkt"
          (for-syntax racket/base))
 
 (define-struct context-record (stx index kind))
diff --git a/collects/stepper/private/macro-unwind.rkt b/collects/stepper/private/macro-unwind.rkt
index ca89a622ac..6c798491ba 100644
--- a/collects/stepper/private/macro-unwind.rkt
+++ b/collects/stepper/private/macro-unwind.rkt
@@ -1,8 +1,8 @@
 #lang racket
 
 (require (only-in syntax/kerncase kernel-syntax-case)
-         "model-settings.ss"
-         "shared.ss")
+         "model-settings.rkt"
+         "shared.rkt")
 
   (provide/contract [unwind (syntax? render-settings? . -> . syntax?)])
                                                                                ;
@@ -365,4 +365,4 @@
   (and (equal? (syntax-property stx1 'user-source)
                (syntax-property stx2 'user-source))
        (equal? (syntax-property stx1 'user-position)
-               (syntax-property stx2 'user-position))))
\ No newline at end of file
+               (syntax-property stx2 'user-position))))
diff --git a/collects/stepper/private/marks.rkt b/collects/stepper/private/marks.rkt
index e56812d67c..24b7aad69e 100644
--- a/collects/stepper/private/marks.rkt
+++ b/collects/stepper/private/marks.rkt
@@ -2,8 +2,8 @@
 
 (require mzlib/list
          mzlib/contract
-         "my-macros.ss"
-         "shared.ss"
+         "my-macros.rkt"
+         "shared.rkt"
          #;(file "/Users/clements/clements/scheme-scraps/eli-debug.ss"))
 
 (define-struct full-mark-struct (source label bindings values))
diff --git a/collects/stepper/private/model.rkt b/collects/stepper/private/model.rkt
index e33f46bc29..39c2893ff0 100644
--- a/collects/stepper/private/model.rkt
+++ b/collects/stepper/private/model.rkt
@@ -42,18 +42,18 @@
          scheme/match
          scheme/class
          scheme/list
-         (prefix-in a: "annotate.ss")
-         (prefix-in r: "reconstruct.ss")
-         "shared.ss"
-         "marks.ss"
-         "model-settings.ss"
-         "macro-unwind.ss"
-         "lifting.ss"
+         (prefix-in a: "annotate.rkt")
+         (prefix-in r: "reconstruct.rkt")
+         "shared.rkt"
+         "marks.rkt"
+         "model-settings.rkt"
+         "macro-unwind.rkt"
+         "lifting.rkt"
          (prefix-in test-engine: test-engine/scheme-tests)
          #;(file "/Users/clements/clements/scheme-scraps/eli-debug.ss")
          ;; for breakpoint display
          ;; (commented out to allow nightly testing)
-         #;"display-break-stuff.ss"
+         #;"display-break-stuff.rkt"
          (for-syntax scheme/base))
 
 (define stepper-model-debug? (make-parameter #f))
@@ -502,7 +502,7 @@
   (define maybe-lift
     (if (render-settings-lifting? render-settings)
         lift
-        ;; ... oh dear; model.ss should disable the double-break & late-let break when lifting is off.
+        ;; ... oh dear; model.rkt should disable the double-break & late-let break when lifting is off.
         (lambda (stx dont-care) (list stx))))
   
   (define (step-through-expression expanded expand-next-expression)
diff --git a/collects/stepper/private/mred-extensions.rkt b/collects/stepper/private/mred-extensions.rkt
index 424324935c..ddeb5e03c4 100644
--- a/collects/stepper/private/mred-extensions.rkt
+++ b/collects/stepper/private/mred-extensions.rkt
@@ -4,8 +4,8 @@
          mred
          (prefix-in f: framework)
          mzlib/pretty
-         #;"testing-shared.ss"
-         "shared.ss")
+         #;"testing-shared.rkt"
+         "shared.rkt")
 
 (provide
  foot-img/horizontal
diff --git a/collects/stepper/private/reconstruct.rkt b/collects/stepper/private/reconstruct.rkt
index 9fcc209057..b562a13028 100644
--- a/collects/stepper/private/reconstruct.rkt
+++ b/collects/stepper/private/reconstruct.rkt
@@ -9,10 +9,10 @@
            mzlib/etc
 	   mzlib/contract
            scheme/match
-           "marks.ss"
-           "model-settings.ss"
-           "shared.ss"
-           "my-macros.ss"
+           "marks.rkt"
+           "model-settings.rkt"
+           "shared.rkt"
+           "my-macros.rkt"
            (for-syntax scheme/base)
            racket/private/promise)
 
diff --git a/collects/stepper/private/shared.rkt b/collects/stepper/private/shared.rkt
index 656be19956..ed7d7e5924 100644
--- a/collects/stepper/private/shared.rkt
+++ b/collects/stepper/private/shared.rkt
@@ -553,7 +553,7 @@
   ;; (equal? (get-set-pair-union-stats)
   ;         `(((2 . 3) 1) ((2 . 1) 2) ((1 . 2) 2)))
 
-  ;; until this remove* goes into list.ss?
+  ;; until this remove* goes into list.rkt?
 
   (define (set-pair-union a-set b-set comparator)
     (cond [(null? b-set) a-set]
diff --git a/collects/stepper/private/testing-shared.rkt b/collects/stepper/private/testing-shared.rkt
index f13acd01a7..0de0241565 100644
--- a/collects/stepper/private/testing-shared.rkt
+++ b/collects/stepper/private/testing-shared.rkt
@@ -1,6 +1,6 @@
 (module testing-shared mzscheme
   (require mzlib/contract
-           "shared.ss"
+           "shared.rkt"
            syntax/kerncase
            mzlib/file)
   
diff --git a/collects/stepper/private/vertical-separator-snip.rkt b/collects/stepper/private/vertical-separator-snip.rkt
index c63147f0af..d927f272c9 100644
--- a/collects/stepper/private/vertical-separator-snip.rkt
+++ b/collects/stepper/private/vertical-separator-snip.rkt
@@ -1,7 +1,7 @@
 (module vertical-separator-snip mzscheme
   (require mred
-	   mzlib/class
-           "mred-extensions.ss")
+           mzlib/class
+           "mred-extensions.rkt")
   
   (provide snip-class)
   (define snip-class (make-object vertical-separator-snip-class%))
diff --git a/collects/stepper/private/view-controller.rkt b/collects/stepper/private/view-controller.rkt
index e604a5a50e..e3e8e0a81c 100644
--- a/collects/stepper/private/view-controller.rkt
+++ b/collects/stepper/private/view-controller.rkt
@@ -10,11 +10,11 @@
          mred
          string-constants
          racket/async-channel
-         (prefix-in model: "model.ss")
-         (prefix-in x: "mred-extensions.ss")
-         "shared.ss"
-         "model-settings.ss"
-         "xml-sig.ss")
+         (prefix-in model: "model.rkt")
+         (prefix-in x: "mred-extensions.rkt")
+         "shared.rkt"
+         "model-settings.rkt"
+         "xml-sig.rkt")
 
 
 (import drracket:tool^ xml^ stepper-frame^)
diff --git a/collects/stepper/private/xml-box.rkt b/collects/stepper/private/xml-box.rkt
index 69a4d200f6..c582bae6f0 100644
--- a/collects/stepper/private/xml-box.rkt
+++ b/collects/stepper/private/xml-box.rkt
@@ -1,6 +1,6 @@
 (module xml-box scheme/base
   (require mzlib/contract
-           "shared.ss"
+           "shared.rkt"
            (prefix-in kernel: syntax/kerncase))
   
   (provide/contract [rewrite-xml-box (syntax?                  ; stx to rewrite
diff --git a/collects/stepper/private/xml-snip-helpers.rkt b/collects/stepper/private/xml-snip-helpers.rkt
index 33628db796..ec62e0e89b 100644
--- a/collects/stepper/private/xml-snip-helpers.rkt
+++ b/collects/stepper/private/xml-snip-helpers.rkt
@@ -1,11 +1,10 @@
-
 (module xml-snip-helpers mzscheme
   (require xml/xml
            syntax/readerr
            mred
            mzlib/class
            mzlib/list
-           "shared.ss")
+           "shared.rkt")
   
   (provide xml-read-special
            xml-snip<%>
diff --git a/collects/stepper/stepper-tool.rkt b/collects/stepper/stepper-tool.rkt
index cfdec48af6..369bb6294d 100644
--- a/collects/stepper/stepper-tool.rkt
+++ b/collects/stepper/stepper-tool.rkt
@@ -12,7 +12,7 @@
          (prefix-in x: "private/mred-extensions.rkt")
          "private/shared.rkt"
          "private/xml-sig.rkt"
-         "drracket-button.ss") ;; get the stepper-button-callback private-member-name
+         "drracket-button.rkt") ;; get the stepper-button-callback private-member-name
 
 (import drracket:tool^ xml^ view-controller^)
 (export drracket:tool-exports^ stepper-frame^)
@@ -365,7 +365,7 @@
   (drracket:get/extend:extend-definitions-text stepper-definitions-text-mixin)
   (drracket:get/extend:extend-tab stepper-tab-mixin)
   
-  ;; COPIED FROM drracket/private/language.ss
+  ;; COPIED FROM drracket/private/language.rkt
 ;; simple-module-based-language-convert-value : TST STYLE boolean -> TST
 (define (simple-module-based-language-convert-value value settings)
   (case (drracket:language:simple-settings-printing-style settings)
@@ -389,7 +389,7 @@
 
 (define ((leave-snips-alone-hook sh) expr basic-convert sub-convert)
   (if (or (is-a? expr snip%)
-          ;; FIXME: internal in language.ss (to-snip-value? expr)
+          ;; FIXME: internal in language.rkt (to-snip-value? expr)
           )
       expr
       (sh expr basic-convert sub-convert)))
@@ -414,7 +414,7 @@
 
 ;; stepper-convert-hook:
 ;;   (TST (TST -> TST) (TST -> TST) -> TST)
-;; this code copied from various locations in language.ss and rep.ss
+;; this code copied from various locations in language.rkt and rep.rkt
 (define (stepper-print-convert-hook exp basic-convert sub-convert)
   (cond
     [(is-a? exp snip%)
diff --git a/collects/stepper/xml-tool.rkt b/collects/stepper/xml-tool.rkt
index ca30f8f4e2..34cac84528 100644
--- a/collects/stepper/xml-tool.rkt
+++ b/collects/stepper/xml-tool.rkt
@@ -2,7 +2,7 @@
 
 (require "private/xml-snip-helpers.rkt"
          "private/find-tag.rkt"
-         "private/xml-sig.ss"
+         "private/xml-sig.rkt"
          mred
          framework
          drracket/tool
diff --git a/collects/string-constants/private/danish-string-constants.rkt b/collects/string-constants/private/danish-string-constants.rkt
index 90b4319445..109667187e 100644
--- a/collects/string-constants/private/danish-string-constants.rkt
+++ b/collects/string-constants/private/danish-string-constants.rkt
@@ -3,7 +3,7 @@
 When modifying the string constants files,
 please adhere to these guidelines:
 
-- All the entries in english-string-constants.ss have the same format
+- All the entries in english-string-constants.rkt have the same format
   (name string).  If the purpose of an entry you are adding to the
   file is not clear from just the name and string, put a comment next
   to the entry explaining what the string is going to be used for and
@@ -29,8 +29,8 @@ please adhere to these guidelines:
   re-use strings that already exist.  There's no need for yet another
   "Ok" string...
 
-- If you modify an existing string in english-string-constants.ss, go
-  through all the *-string-constants.ss files for the other languages,
+- If you modify an existing string in english-string-constants.rkt, go
+  through all the *-string-constants.rkt files for the other languages,
   comment out the old version of the modified string in each of these
   files, and put a short comment there telling us the English string
   has changed and needs to be re-translated.  Do not erase the old
@@ -72,7 +72,7 @@ please adhere to these guidelines:
 
 - If, for some reason, you really have to change the name of a string
   (like, because the original name you gave it really sucked...),
-  change the name of the string in *ALL* the *-string-constants.ss
+  change the name of the string in *ALL* the *-string-constants.rkt
   files.  That's a modification you can do without the help of a
   translator, so do it yourself.  It's not the job of the translators
   to clean up your naming mess for you.  Besides, you are the one who
@@ -81,14 +81,14 @@ please adhere to these guidelines:
 
 - If, for some reason, you need to remove a string (i.e. you changed
   your code and don't need the string anymore), remove the string in
-  *ALL* the *-string-constants.ss files.  Again, you don't need the
+  *ALL* the *-string-constants.rkt files.  Again, you don't need the
   help of a translator to do that.  If you're not sure whether you
   might need the string in the future or not, just comment it out in
   *ALL* the files.
 
 |#
 
-(module danish-string-constants "string-constant-lang.ss"
+(module danish-string-constants "string-constant-lang.rkt"
   ;;; when translating this constant, substitute name of actual language for `English'
   (is-this-your-native-language "Foretrækker du dansk?")
   
@@ -725,13 +725,13 @@ please adhere to these guidelines:
   (drscheme-internal-error "Intern fejl i DrRacket")
   
   ;;; tools
-  (invalid-tool-spec "Værkstøjsspecifikationen i collection ~a's info.ss filen er ugyldig. Forventede enten en streng eller en ikke-tom liste af strenge, fik: ~e")
+  (invalid-tool-spec "Værkstøjsspecifikationen i collection ~a's info.rkt filen er ugyldig. Forventede enten en streng eller en ikke-tom liste af strenge, fik: ~e")
   (error-invoking-tool-title "Fejl ved kørsel af værktøj ~s;~s")
-  (tool-tool-names-same-length "forventede `tool-names' og `tools' var to lister af samme længde i info.ss for ~s, fik ~e og ~e")
-  (tool-tool-icons-same-length  "forventede `tool-icons' og `tools' var to lister af samme længde i info.ss  for ~s, fik ~e and ~e")
+  (tool-tool-names-same-length "forventede `tool-names' og `tools' var to lister af samme længde i info.rkt for ~s, fik ~e og ~e")
+  (tool-tool-icons-same-length  "forventede `tool-icons' og `tools' var to lister af samme længde i info.rkt  for ~s, fik ~e and ~e")
   (tool-tool-urls-same-length
-   "forventede `tool-urls' og `tools' var lister af samme længde  i info.ss-filen for ~s, fik ~e og ~e")
-  (error-getting-info-tool  "fejl ved hentning af info.ss file for ~s")
+   "forventede `tool-urls' og `tools' var lister af samme længde  i info.rkt-filen for ~s, fik ~e og ~e")
+  (error-getting-info-tool  "fejl ved hentning af info.rkt file for ~s")
   (tool-error-phase1 "Fejl i fase 1 for værktøjet ~s; ~s")
   (tool-error-phase2 "Fejl i fase 2 for værktøjet ~s; ~s")
   
diff --git a/collects/string-constants/private/dutch-string-constants.rkt b/collects/string-constants/private/dutch-string-constants.rkt
index aa7c610a71..87a4890b0d 100644
--- a/collects/string-constants/private/dutch-string-constants.rkt
+++ b/collects/string-constants/private/dutch-string-constants.rkt
@@ -1,4 +1,4 @@
-(module dutch-string-constants "string-constant-lang.ss"
+(module dutch-string-constants "string-constant-lang.rkt"
 
 ;;; -- Where are Undo, Redo, Select all, and friends from the right-click popup menu?
 
@@ -468,14 +468,14 @@
  (drscheme-internal-error "Interne Fout van DrRacket")
  
  ;;; tools <**>
- (invalid-tool-spec "The tool specification in collection ~a's info.ss file is invalid. Expected either a string or a non-empty list of strings, got: ~e")
+ (invalid-tool-spec "The tool specification in collection ~a's info.rkt file is invalid. Expected either a string or a non-empty list of strings, got: ~e")
  (error-invoking-tool-title "Error invoking tool ~s;~s")
  (tool-tool-names-same-length
-  "expected `tool-names' and `tools' to be lists of the same length, in info.ss file for ~s, got ~e and ~e")
+  "expected `tool-names' and `tools' to be lists of the same length, in info.rkt file for ~s, got ~e and ~e")
  (tool-tool-icons-same-length
-  "expected `tool-icons' and `tools' to be lists of the same length, in info.ss file for ~s, got ~e and ~e")
+  "expected `tool-icons' and `tools' to be lists of the same length, in info.rkt file for ~s, got ~e and ~e")
  (error-getting-info-tool
-  "error loading info.ss file for ~s")
+  "error loading info.rkt file for ~s")
  (tool-error-phase1 "Error in phase 1 for tool ~s; ~s")
  (tool-error-phase2 "Error in phase 2 for tool ~s; ~s")
 
diff --git a/collects/string-constants/private/english-string-constants.rkt b/collects/string-constants/private/english-string-constants.rkt
index 90464e0e27..7695f33239 100644
--- a/collects/string-constants/private/english-string-constants.rkt
+++ b/collects/string-constants/private/english-string-constants.rkt
@@ -3,7 +3,7 @@
 When modifying the string constants files,
 please adhere to these guidelines:
 
-- All the entries in english-string-constants.ss have the same format
+- All the entries in english-string-constants.rkt have the same format
   (name string).  If the purpose of an entry you are adding to the
   file is not clear from just the name and string, put a comment next
   to the entry explaining what the string is going to be used for and
@@ -29,8 +29,8 @@ please adhere to these guidelines:
   re-use strings that already exist.  There's no need for yet another
   "Ok" string...
 
-- If you modify an existing string in english-string-constants.ss, go
-  through all the *-string-constants.ss files for the other languages,
+- If you modify an existing string in english-string-constants.rkt, go
+  through all the *-string-constants.rkt files for the other languages,
   comment out the old version of the modified string in each of these
   files, and put a short comment there telling us the English string
   has changed and needs to be re-translated.  Do not erase the old
@@ -72,7 +72,7 @@ please adhere to these guidelines:
 
 - If, for some reason, you really have to change the name of a string
   (like, because the original name you gave it really sucked...),
-  change the name of the string in *ALL* the *-string-constants.ss
+  change the name of the string in *ALL* the *-string-constants.rkt
   files.  That's a modification you can do without the help of a
   translator, so do it yourself.  It's not the job of the translators
   to clean up your naming mess for you.  Besides, you are the one who
@@ -81,14 +81,14 @@ please adhere to these guidelines:
 
 - If, for some reason, you need to remove a string (i.e. you changed
   your code and don't need the string anymore), remove the string in
-  *ALL* the *-string-constants.ss files.  Again, you don't need the
+  *ALL* the *-string-constants.rkt files.  Again, you don't need the
   help of a translator to do that.  If you're not sure whether you
   might need the string in the future or not, just comment it out in
   *ALL* the files.
 
 |#
 
-(module english-string-constants "string-constant-lang.ss"
+(module english-string-constants "string-constant-lang.rkt"
  ;;; when translating this constant, substitute name of actual language for `English'
  (is-this-your-native-language "Is English Your Native Language?")
 
@@ -842,17 +842,17 @@ please adhere to these guidelines:
  (drscheme-internal-error "DrRacket Internal Error")
  
  ;;; tools
- (invalid-tool-spec "The tool specification in collection ~a's info.ss file is invalid. Expected either a string or a non-empty list of strings, got: ~e")
+ (invalid-tool-spec "The tool specification in collection ~a's info.rkt file is invalid. Expected either a string or a non-empty list of strings, got: ~e")
  (error-invoking-tool-title "Error invoking tool ~s;~s")
  (error-loading-tool-title "Error loading tool ~s\n~a") ;; ~s filled with a path, ~a filled with an error message from an exn
  (tool-tool-names-same-length
-  "expected `tool-names' and `tools' to be lists of the same length, in info.ss file for ~s, got ~e and ~e")
+  "expected `tool-names' and `tools' to be lists of the same length, in info.rkt file for ~s, got ~e and ~e")
  (tool-tool-icons-same-length
-  "expected `tool-icons' and `tools' to be lists of the same length, in info.ss file for ~s, got ~e and ~e")
+  "expected `tool-icons' and `tools' to be lists of the same length, in info.rkt file for ~s, got ~e and ~e")
  (tool-tool-urls-same-length
-  "expected `tool-urls' and `tools' to be lists of the same length, in info.ss file for ~s, got ~e and ~e")
+  "expected `tool-urls' and `tools' to be lists of the same length, in info.rkt file for ~s, got ~e and ~e")
  (error-getting-info-tool
-  "error loading info.ss file for ~s")
+  "error loading info.rkt file for ~s")
  (tool-error-phase1 "Error in phase 1 for tool ~s; ~s")
  (tool-error-phase2 "Error in phase 2 for tool ~s; ~s")
 
diff --git a/collects/string-constants/private/french-string-constants.rkt b/collects/string-constants/private/french-string-constants.rkt
index 98d9fc501c..5040a53ea7 100644
--- a/collects/string-constants/private/french-string-constants.rkt
+++ b/collects/string-constants/private/french-string-constants.rkt
@@ -1,6 +1,6 @@
 
 ; Do not remove all these blank lines, I use them to make sure a translation 
-; in this file appears on the same line as in english-string-constants.ss
+; in this file appears on the same line as in english-string-constants.rkt
 
 ; "aâàbcçdeéêèëfghiîïjklmnoôpqrstuûùüvwxyz" "AÂÀBCÇDEÉÊÈËFGHIÎÏJKLMNOÔPQRSTUÛÙÜVWXYZ"
 
@@ -88,7 +88,7 @@
 
 
 
-(module french-string-constants "string-constant-lang.ss"
+(module french-string-constants "string-constant-lang.rkt"
   ;;; when translating this constant, substitue name of actual language for `English'
   (is-this-your-native-language "Le Français est-il votre langue maternelle ?")
   
@@ -826,17 +826,17 @@
   (drscheme-internal-error "Erreur interne de DrRacket.")
   
   ;;; tools
-  (invalid-tool-spec "La spécification d'outil qui se trouve dans le fichier info.ss de la collection ~a est invalide. Espérait soit une chaîne de caractères, soit une liste de chaînes de caractères, trouvé : ~e")
+  (invalid-tool-spec "La spécification d'outil qui se trouve dans le fichier info.rkt de la collection ~a est invalide. Espérait soit une chaîne de caractères, soit une liste de chaînes de caractères, trouvé : ~e")
   (error-invoking-tool-title "Erreur durant l'invocation de l'outil ~s;~s")
   (error-loading-tool-title "Erreur durant le chargement de l'outil ~s\n~a") ;; ~s filled with a path, ~a filled with an error message from an exn
   (tool-tool-names-same-length
-   "`tool-names' et `tools' ne sont pas des listes de la même longueur, dans le fichier info.ss pour ~s. Trouvé ~e et ~e")
+   "`tool-names' et `tools' ne sont pas des listes de la même longueur, dans le fichier info.rkt pour ~s. Trouvé ~e et ~e")
   (tool-tool-icons-same-length
-   "`tool-icons' et `tools' ne sont pas des listes de la même longueur, dans le fichier info.ss pour ~s. Trouvé ~e et ~e")
+   "`tool-icons' et `tools' ne sont pas des listes de la même longueur, dans le fichier info.rkt pour ~s. Trouvé ~e et ~e")
   (tool-tool-urls-same-length
-   "`tool-urls' et `tools' ne sont pas des listes de la même longueur, dans le fichier info.ss pour ~s. Trouvé ~e et ~e")
+   "`tool-urls' et `tools' ne sont pas des listes de la même longueur, dans le fichier info.rkt pour ~s. Trouvé ~e et ~e")
   (error-getting-info-tool
-   "erreur durant le chargement du fichier info.ss pour ~s")
+   "erreur durant le chargement du fichier info.rkt pour ~s")
   (tool-error-phase1 "Erreur durant la phase 1 pour l'outil ~s; ~s")
   (tool-error-phase2 "Erreur durant la phase 2 oour l'outil ~s; ~s")
   
diff --git a/collects/string-constants/private/german-string-constants.rkt b/collects/string-constants/private/german-string-constants.rkt
index 3540e872c4..ba038fef67 100644
--- a/collects/string-constants/private/german-string-constants.rkt
+++ b/collects/string-constants/private/german-string-constants.rkt
@@ -1,4 +1,4 @@
-(module german-string-constants "string-constant-lang.ss"
+(module german-string-constants "string-constant-lang.rkt"
 
  (is-this-your-native-language
   "Ist Deutsch Ihre Muttersprache?")
@@ -738,17 +738,17 @@
  (drscheme-internal-error "Interner Fehler in DrRacket")
  
  ;;; tools
- (invalid-tool-spec "Die Tool-Spezifikation in der Datei info.ss der Kollektion ~a enthält Fehler. Da sollte eine Zeichenkette oder eine Liste von Zeichenketten stehen, tatsächlich steht dort aber: ~e")
+ (invalid-tool-spec "Die Tool-Spezifikation in der Datei info.rkt der Kollektion ~a enthält Fehler. Da sollte eine Zeichenkette oder eine Liste von Zeichenketten stehen, tatsächlich steht dort aber: ~e")
  (error-invoking-tool-title "Fehler beim Starten von Tool ~s;~s")
  (error-loading-tool-title "Fehler beim Laden von Tool ~s\n~a") ;; ~s filled with a path, ~a filled with an error message from an exn
  (tool-tool-names-same-length
-  "`tool-names' und `tools' in info.ss für ~s müssen Listen der gleichen Länge sein, tatsächlich stehen dort ~e und ~e")
+  "`tool-names' und `tools' in info.rkt für ~s müssen Listen der gleichen Länge sein, tatsächlich stehen dort ~e und ~e")
  (tool-tool-icons-same-length
-  "`tool-icons' und `tools' in info.ss für ~s müssen Listen der gleichen Länge sein, tatsächlich stehen dort ~e und ~e")
+  "`tool-icons' und `tools' in info.rkt für ~s müssen Listen der gleichen Länge sein, tatsächlich stehen dort ~e und ~e")
  (tool-tool-urls-same-length
-  "`tool-urls' und `tools' in info.ss für ~s müssen Listen der gleichen Länge sein, tatsächlich stehen dort ~e und ~e")
+  "`tool-urls' und `tools' in info.rkt für ~s müssen Listen der gleichen Länge sein, tatsächlich stehen dort ~e und ~e")
  (error-getting-info-tool
-  "Fehler beim Laden von info.ss file für ~s")
+  "Fehler beim Laden von info.rkt file für ~s")
  (tool-error-phase1 "Fehler in Phase 1 von Tool ~s; ~s")
  (tool-error-phase2 "Fehler in Phase 2 von Tool ~s; ~s")
 
diff --git a/collects/string-constants/private/japanese-string-constants.rkt b/collects/string-constants/private/japanese-string-constants.rkt
index f54e686b0e..f8f64a66ec 100644
--- a/collects/string-constants/private/japanese-string-constants.rkt
+++ b/collects/string-constants/private/japanese-string-constants.rkt
@@ -3,7 +3,7 @@
 When modifying the string constants files,
 please adhere to these guidelines:
 
-- All the entries in english-string-constants.ss have the same format
+- All the entries in english-string-constants.rkt have the same format
   (name string).  If the purpose of an entry you are adding to the
   file is not clear from just the name and string, put a comment next
   to the entry explaining what the string is going to be used for and
@@ -29,8 +29,8 @@ please adhere to these guidelines:
   re-use strings that already exist.  There's no need for yet another
   "Ok" string...
 
-- If you modify an existing string in english-string-constants.ss, go
-  through all the *-string-constants.ss files for the other languages,
+- If you modify an existing string in english-string-constants.rkt, go
+  through all the *-string-constants.rkt files for the other languages,
   comment out the old version of the modified string in each of these
   files, and put a short comment there telling us the English string
   has changed and needs to be re-translated.  Do not erase the old
@@ -72,7 +72,7 @@ please adhere to these guidelines:
 
 - If, for some reason, you really have to change the name of a string
   (like, because the original name you gave it really sucked...),
-  change the name of the string in *ALL* the *-string-constants.ss
+  change the name of the string in *ALL* the *-string-constants.rkt
   files.  That's a modification you can do without the help of a
   translator, so do it yourself.  It's not the job of the translators
   to clean up your naming mess for you.  Besides, you are the one who
@@ -81,14 +81,14 @@ please adhere to these guidelines:
 
 - If, for some reason, you need to remove a string (i.e. you changed
   your code and don't need the string anymore), remove the string in
-  *ALL* the *-string-constants.ss files.  Again, you don't need the
+  *ALL* the *-string-constants.rkt files.  Again, you don't need the
   help of a translator to do that.  If you're not sure whether you
   might need the string in the future or not, just comment it out in
   *ALL* the files.
 
 |#
 
-(module japanese-string-constants "string-constant-lang.ss"
+(module japanese-string-constants "string-constant-lang.rkt"
  ;;; when translating this constant, substitute name of actual language for `English'
  (is-this-your-native-language "Is Japanese Your Native Language?")
 
@@ -799,16 +799,16 @@ please adhere to these guidelines:
  (drscheme-internal-error "DrRacket 内部エラー")
 
  ;;; tools
- (invalid-tool-spec "コレクション ~a の info.ss ファイルに記述されているツール仕様が不正です。文字列か空でない文字列リストでなければなりませんが、次の値が記述されています: ~e")
+ (invalid-tool-spec "コレクション ~a の info.rkt ファイルに記述されているツール仕様が不正です。文字列か空でない文字列リストでなければなりませんが、次の値が記述されています: ~e")
  (error-invoking-tool-title "ツール ~s を起動時にエラーが発生しました: ~s")
  (tool-tool-names-same-length
-  "expected `tool-names' and `tools' to be lists of the same length, in info.ss file for ~s, got ~e and ~e")
+  "expected `tool-names' and `tools' to be lists of the same length, in info.rkt file for ~s, got ~e and ~e")
  (tool-tool-icons-same-length
-  "expected `tool-icons' and `tools' to be lists of the same length, in info.ss file for ~s, got ~e and ~e")
+  "expected `tool-icons' and `tools' to be lists of the same length, in info.rkt file for ~s, got ~e and ~e")
  (tool-tool-urls-same-length
-  "expected `tool-urls' and `tools' to be lists of the same length, in info.ss file for ~s, got ~e and ~e")
+  "expected `tool-urls' and `tools' to be lists of the same length, in info.rkt file for ~s, got ~e and ~e")
  (error-getting-info-tool
-  "~s の info.ss をロード時にエラーが発生しました")
+  "~s の info.rkt をロード時にエラーが発生しました")
  (tool-error-phase1 "ツール ~s のフェーズ 1 でエラーが発生しました: ~s")
  (tool-error-phase2 "ツール ~s のフェーズ 2 でエラーが発生しました: ~s")
 
diff --git a/collects/string-constants/private/korean-string-constants.rkt b/collects/string-constants/private/korean-string-constants.rkt
index 7ffb079625..333f6f2d96 100644
--- a/collects/string-constants/private/korean-string-constants.rkt
+++ b/collects/string-constants/private/korean-string-constants.rkt
@@ -7,7 +7,7 @@
 ;;                Yujeong Cho <mayflower418@gmail.com>,
 ;;                Sung Gyeong Bae <imai0917@gmail.com>
 ;;
-(module korean-string-constants "string-constant-lang.ss"
+(module korean-string-constants "string-constant-lang.rkt"
  (is-this-your-native-language "한글을 사용하시겠습니까?")
 
  (are-you-sure-you-want-to-switch-languages
@@ -731,17 +731,17 @@
  (drscheme-internal-error "DrRacket 내부 오류")
  
  ;;; tools
- (invalid-tool-spec "info.ss 파일(collection ~a) 안에 있는 도구 세부 정보가 잘못되었습니다. 문자열 또는 문자열의 목록이 있어야 하는데, ~e이(가) 있습니다.")
+ (invalid-tool-spec "info.rkt 파일(collection ~a) 안에 있는 도구 세부 정보가 잘못되었습니다. 문자열 또는 문자열의 목록이 있어야 하는데, ~e이(가) 있습니다.")
  (error-invoking-tool-title "~s 도구를 가져오는데 ;~s 오류가 발생하였습니다.")
  (error-loading-tool-title "~s 도구를 불러오는데 \n~a 오류가 발생하였습니다.") ;; ~s filled with a path, ~a filled with an error message from an exn
  (tool-tool-names-same-length
-  "info.ss 파일(~s)의 `tool-names' 와 `tools' 이 같은 길이의 목록이어야 하는데 ~e와(과) ~e이(가) 있습니다.")
+  "info.rkt 파일(~s)의 `tool-names' 와 `tools' 이 같은 길이의 목록이어야 하는데 ~e와(과) ~e이(가) 있습니다.")
  (tool-tool-icons-same-length
-  "info.ss 파일(~s)의 `tool-icons' 와 `tools' 이 같은 길이의 목록이어야 하는데 ~e와(과) ~e이(가) 있습니다.")
+  "info.rkt 파일(~s)의 `tool-icons' 와 `tools' 이 같은 길이의 목록이어야 하는데 ~e와(과) ~e이(가) 있습니다.")
  (tool-tool-urls-same-length
-  "info.ss 파일(~s)의 `tool-urls' 와 `tools' 이 같은 길이의 목록이어야 하는데 ~e와(과) ~e이(가) 있습니다.")
+  "info.rkt 파일(~s)의 `tool-urls' 와 `tools' 이 같은 길이의 목록이어야 하는데 ~e와(과) ~e이(가) 있습니다.")
  (error-getting-info-tool
-  "info.ss 파일(~s)을 불러오는데 오류가 발생하였습니다.")
+  "info.rkt 파일(~s)을 불러오는데 오류가 발생하였습니다.")
  (tool-error-phase1 "도구 ~s의 phase1에 ~s 오류가 발생하였습니다.")
  (tool-error-phase2 "도구 ~s의 phase2에 ~s 오류가 발생하였습니다.")
 
diff --git a/collects/string-constants/private/portuguese-string-constants.rkt b/collects/string-constants/private/portuguese-string-constants.rkt
index 37a994aba8..3b8b0c2692 100644
--- a/collects/string-constants/private/portuguese-string-constants.rkt
+++ b/collects/string-constants/private/portuguese-string-constants.rkt
@@ -3,7 +3,7 @@
 When modifying the string constants files,
 please adhere to these guidelines:
 
-- All the entries in english-string-constants.ss have the same format
+- All the entries in english-string-constants.rkt have the same format
   (name string).  If the purpose of an entry you are adding to the
   file is not clear from just the name and string, put a comment next
   to the entry explaining what the string is going to be used for and
@@ -29,8 +29,8 @@ please adhere to these guidelines:
   re-use strings that already exist.  There's no need for yet another
   "Ok" string...
 
-- If you modify an existing string in english-string-constants.ss, go
-  through all the *-string-constants.ss files for the other languages,
+- If you modify an existing string in english-string-constants.rkt, go
+  through all the *-string-constants.rkt files for the other languages,
   comment out the old version of the modified string in each of these
   files, and put a short comment there telling us the English string
   has changed and needs to be re-translated.  Do not erase the old
@@ -72,7 +72,7 @@ please adhere to these guidelines:
 
 - If, for some reason, you really have to change the name of a string
   (like, because the original name you gave it really sucked...),
-  change the name of the string in *ALL* the *-string-constants.ss
+  change the name of the string in *ALL* the *-string-constants.rkt
   files.  That's a modification you can do without the help of a
   translator, so do it yourself.  It's not the job of the translators
   to clean up your naming mess for you.  Besides, you are the one who
@@ -81,14 +81,14 @@ please adhere to these guidelines:
 
 - If, for some reason, you need to remove a string (i.e. you changed
   your code and don't need the string anymore), remove the string in
-  *ALL* the *-string-constants.ss files.  Again, you don't need the
+  *ALL* the *-string-constants.rkt files.  Again, you don't need the
   help of a translator to do that.  If you're not sure whether you
   might need the string in the future or not, just comment it out in
   *ALL* the files.
 
 |#
 
-(module portuguese-string-constants "string-constant-lang.ss"
+(module portuguese-string-constants "string-constant-lang.rkt"
  ;;; when translating this constant, substitute name of actual language for `English'
  (is-this-your-native-language "Português é a tua língua materna?")
 
@@ -712,16 +712,16 @@ please adhere to these guidelines:
  (drscheme-internal-error "DrRacket Internal Error")
  
  ;;; tools
- (invalid-tool-spec "The tool specification in collection ~a's info.ss file is invalid. Expected either a string or a non-empty list of strings, got: ~e")
+ (invalid-tool-spec "The tool specification in collection ~a's info.rkt file is invalid. Expected either a string or a non-empty list of strings, got: ~e")
  (error-invoking-tool-title "Error invoking tool ~s;~s")
  (tool-tool-names-same-length
-  "expected `tool-names' and `tools' to be lists of the same length, in info.ss file for ~s, got ~e and ~e")
+  "expected `tool-names' and `tools' to be lists of the same length, in info.rkt file for ~s, got ~e and ~e")
  (tool-tool-icons-same-length
-  "expected `tool-icons' and `tools' to be lists of the same length, in info.ss file for ~s, got ~e and ~e")
+  "expected `tool-icons' and `tools' to be lists of the same length, in info.rkt file for ~s, got ~e and ~e")
  (tool-tool-urls-same-length
-  "expected `tool-urls' and `tools' to be lists of the same length, in info.ss file for ~s, got ~e and ~e")
+  "expected `tool-urls' and `tools' to be lists of the same length, in info.rkt file for ~s, got ~e and ~e")
  (error-getting-info-tool
-  "error loading info.ss file for ~s")
+  "error loading info.rkt file for ~s")
  (tool-error-phase1 "Error in phase 1 for tool ~s; ~s")
  (tool-error-phase2 "Error in phase 2 for tool ~s; ~s")
 
diff --git a/collects/string-constants/private/russian-string-constants.rkt b/collects/string-constants/private/russian-string-constants.rkt
index a8648342e9..9a3db8f0b2 100644
--- a/collects/string-constants/private/russian-string-constants.rkt
+++ b/collects/string-constants/private/russian-string-constants.rkt
@@ -3,7 +3,7 @@
 When modifying the string constants files,
 please adhere to these guidelines:
 
-- All the entries in english-string-constants.ss have the same format
+- All the entries in english-string-constants.rkt have the same format
   (name string).  If the purpose of an entry you are adding to the
   file is not clear from just the name and string, put a comment next
   to the entry explaining what the string is going to be used for and
@@ -29,8 +29,8 @@ please adhere to these guidelines:
   re-use strings that already exist.  There's no need for yet another
   "Ok" string...
 
-- If you modify an existing string in english-string-constants.ss, go
-  through all the *-string-constants.ss files for the other languages,
+- If you modify an existing string in english-string-constants.rkt, go
+  through all the *-string-constants.rkt files for the other languages,
   comment out the old version of the modified string in each of these
   files, and put a short comment there telling us the English string
   has changed and needs to be re-translated.  Do not erase the old
@@ -72,7 +72,7 @@ please adhere to these guidelines:
 
 - If, for some reason, you really have to change the name of a string
   (like, because the original name you gave it really sucked...),
-  change the name of the string in *ALL* the *-string-constants.ss
+  change the name of the string in *ALL* the *-string-constants.rkt
   files.  That's a modification you can do without the help of a
   translator, so do it yourself.  It's not the job of the translators
   to clean up your naming mess for you.  Besides, you are the one who
@@ -81,14 +81,14 @@ please adhere to these guidelines:
 
 - If, for some reason, you need to remove a string (i.e. you changed
   your code and don't need the string anymore), remove the string in
-  *ALL* the *-string-constants.ss files.  Again, you don't need the
+  *ALL* the *-string-constants.rkt files.  Again, you don't need the
   help of a translator to do that.  If you're not sure whether you
   might need the string in the future or not, just comment it out in
   *ALL* the files.
 
 |#
 
-(module russian-string-constants "string-constant-lang.ss"
+(module russian-string-constants "string-constant-lang.rkt"
  ;;; when translating this constant, substitute name of actual langauge for `English'
  (is-this-your-native-language "Русский - это Ваш родной язык?")
 
@@ -805,17 +805,17 @@ please adhere to these guidelines:
  (drscheme-internal-error "Внутренняя ошибка DrRacket")
  
  ;;; tools
- (invalid-tool-spec "Некорректный файл info.ss, содержащий описание инструмента в коллекции ~a. Ожидается строка или непустой список строк, получено: ~e")
+ (invalid-tool-spec "Некорректный файл info.rkt, содержащий описание инструмента в коллекции ~a. Ожидается строка или непустой список строк, получено: ~e")
  (error-invoking-tool-title "Ошибка вызова инструмента ~s;~s")
  (error-loading-tool-title "Ошибка загрузки инструмента ~s\n~a") ;; ~s filled with a path, ~a filled with an error message from an exn
  (tool-tool-names-same-length
-  "В файле info.ss для ~s ожидается, что `tool-names' и `tools' - списки равной длины, получено ~e и ~e")
+  "В файле info.rkt для ~s ожидается, что `tool-names' и `tools' - списки равной длины, получено ~e и ~e")
  (tool-tool-icons-same-length
-  "В файле info.ss для ~s ожидается, что `tool-icons' и `tools' - списки равной длины, получено ~e и ~e")
+  "В файле info.rkt для ~s ожидается, что `tool-icons' и `tools' - списки равной длины, получено ~e и ~e")
  (tool-tool-urls-same-length
-  "В файле info.ss для ~s ожидается, что `tool-urls' и `tools' - списки равной длины, получено ~e и ~e")
+  "В файле info.rkt для ~s ожидается, что `tool-urls' и `tools' - списки равной длины, получено ~e и ~e")
  (error-getting-info-tool
-  "ошибка при загрузке файла info.ss для ~s")
+  "ошибка при загрузке файла info.rkt для ~s")
  (tool-error-phase1 "Ошибка на 1 этапе для инструмента ~s; ~s")
  (tool-error-phase2 "Ошибка на 2 этапе для инструмента ~s; ~s")
 
diff --git a/collects/string-constants/private/simplified-chinese-string-constants.rkt b/collects/string-constants/private/simplified-chinese-string-constants.rkt
index 714648f79a..e16d2dc653 100644
--- a/collects/string-constants/private/simplified-chinese-string-constants.rkt
+++ b/collects/string-constants/private/simplified-chinese-string-constants.rkt
@@ -16,7 +16,7 @@
 ;   ##      ##           ##   ####     ##      #    #       ## 
 ;           #                   #                    #######   
 ;                                                              
-(module simplified-chinese-string-constants "string-constant-lang.ss"
+(module simplified-chinese-string-constants "string-constant-lang.rkt"
   (is-this-your-native-language "中文是你的母语吗？")
   
   (are-you-sure-you-want-to-switch-languages
@@ -709,16 +709,16 @@
   (drscheme-internal-error "DrRacket内部错误")
   
   ;;; tools
-  (invalid-tool-spec "Collection ~a中info.ss的tool定义不正确。需要一个字符串或者一个非空表，得到：~e")
+  (invalid-tool-spec "Collection ~a中info.rkt的tool定义不正确。需要一个字符串或者一个非空表，得到：~e")
   (error-invoking-tool-title "调用tool ~s出错；~s")
   (tool-tool-names-same-length
-   "在~s的info.ss文件中，“tool-names”和“tools”应该是等长的表，得到~e和~e")
+   "在~s的info.rkt文件中，“tool-names”和“tools”应该是等长的表，得到~e和~e")
   (tool-tool-icons-same-length
-   "在~s的info.ss文件中，“tool-icons”和“tools”应该是等长的表，得到~e和~e")
+   "在~s的info.rkt文件中，“tool-icons”和“tools”应该是等长的表，得到~e和~e")
   (tool-tool-urls-same-length
-   "在~s的info.ss文件中，“tool-urls”和“tools”应该是等长的表，得到~e和~e")
+   "在~s的info.rkt文件中，“tool-urls”和“tools”应该是等长的表，得到~e和~e")
   (error-getting-info-tool
-   "载入~s的info.ss出错")
+   "载入~s的info.rkt出错")
   (tool-error-phase1 "tool ~s第一阶段出错;~s")
   (tool-error-phase2 "tool ~s第二阶段出错;~s")
   
diff --git a/collects/string-constants/private/spanish-string-constants.rkt b/collects/string-constants/private/spanish-string-constants.rkt
index effdd4d683..88178fbd6f 100644
--- a/collects/string-constants/private/spanish-string-constants.rkt
+++ b/collects/string-constants/private/spanish-string-constants.rkt
@@ -1,4 +1,4 @@
-(module spanish-string-constants "string-constant-lang.ss"
+(module spanish-string-constants "string-constant-lang.rkt"
 
  ;;; when translating this constant, substitue name of actual language for `English'
  (is-this-your-native-language
@@ -602,15 +602,15 @@
  (drscheme-internal-error "Error interno de DrRacket")
  
  ;;; tools
- (invalid-tool-spec "La especificación de la herramienta, especificada en el archivo info.ss de la colección ~a, es inválida.  Esperaba una cadena o una lista no vacía de cadenas y recibí: ~e")
+ (invalid-tool-spec "La especificación de la herramienta, especificada en el archivo info.rkt de la colección ~a, es inválida.  Esperaba una cadena o una lista no vacía de cadenas y recibí: ~e")
  (error-invoking-tool-title "Error al invocar la herramienta ~s;~s")
  (tool-tool-names-same-length
-  "esperaba que `tool-names' y `tools', en el archivo info.ss de ~s, fueran listas de la misma longitud, pero obtuve ~e y ~e")
+  "esperaba que `tool-names' y `tools', en el archivo info.rkt de ~s, fueran listas de la misma longitud, pero obtuve ~e y ~e")
  (tool-tool-icons-same-length
-  "esperaba que `tool-icons' y  `tools', en el archivo info.ss de ~s, fueran listas de la misma longitud, pero obtuve ~e y ~e")
+  "esperaba que `tool-icons' y  `tools', en el archivo info.rkt de ~s, fueran listas de la misma longitud, pero obtuve ~e y ~e")
  (tool-tool-urls-same-length
-  "esperaba que `tool-urls' y `tools' fueran listas del mismo tamaño en info.ss de ~s, pero obtuve ~e y ~e")
- (error-getting-info-tool "error al cargar el archivo info.ss de ~s")
+  "esperaba que `tool-urls' y `tools' fueran listas del mismo tamaño en info.rkt de ~s, pero obtuve ~e y ~e")
+ (error-getting-info-tool "error al cargar el archivo info.rkt de ~s")
  (tool-error-phase1 "Error en la fase 1 de la herramienta ~s; ~s")
  (tool-error-phase2 "Error en la fase 2 de la herramienta ~s; ~s")
 
diff --git a/collects/string-constants/private/traditional-chinese-string-constants.rkt b/collects/string-constants/private/traditional-chinese-string-constants.rkt
index 5aea32505d..b84412f9f9 100644
--- a/collects/string-constants/private/traditional-chinese-string-constants.rkt
+++ b/collects/string-constants/private/traditional-chinese-string-constants.rkt
@@ -15,7 +15,7 @@
 ;     ;;     ;;      ;;      ;;     ;     ;;       ;;     ;;  ;      
 ;   ;;       ;;             ;    ;;;;      ;       ;;     ;  ;    ;  
 ;            ;;                    ;               ;   ;;; ;; ;;;;   
-(module traditional-chinese-string-constants "string-constant-lang.ss"
+(module traditional-chinese-string-constants "string-constant-lang.rkt"
   (is-this-your-native-language "中文是你的母語嗎？")
   
   (are-you-sure-you-want-to-switch-languages
@@ -708,16 +708,16 @@
   (drscheme-internal-error "DrRacket内部错误")
   
   ;;; tools
-  (invalid-tool-spec "Collection ~a中info.ss的tool定义不正确。需要一个字符串或者一个非空表，得到：~e")
+  (invalid-tool-spec "Collection ~a中info.rkt的tool定义不正确。需要一个字符串或者一个非空表，得到：~e")
   (error-invoking-tool-title "调用tool ~s出错；~s")
   (tool-tool-names-same-length
-   "在~s的info.ss文件中，“tool-names”和“tools”应该是等长的表，得到~e和~e")
+   "在~s的info.rkt文件中，“tool-names”和“tools”应该是等长的表，得到~e和~e")
   (tool-tool-icons-same-length
-   "在~s的info.ss文件中，“tool-icons”和“tools”应该是等长的表，得到~e和~e")
+   "在~s的info.rkt文件中，“tool-icons”和“tools”应该是等长的表，得到~e和~e")
   (tool-tool-urls-same-length
-   "在~s的info.ss文件中，“tool-urls”和“tools”应该是等长的表，得到~e和~e")
+   "在~s的info.rkt文件中，“tool-urls”和“tools”应该是等长的表，得到~e和~e")
   (error-getting-info-tool
-   "载入~s的info.ss出错")
+   "载入~s的info.rkt出错")
   (tool-error-phase1 "tool ~s第一阶段出错;~s")
   (tool-error-phase2 "tool ~s第二阶段出错;~s")
   
diff --git a/collects/string-constants/private/ukrainian-string-constants.rkt b/collects/string-constants/private/ukrainian-string-constants.rkt
index 9b8e542fdf..f40decb209 100644
--- a/collects/string-constants/private/ukrainian-string-constants.rkt
+++ b/collects/string-constants/private/ukrainian-string-constants.rkt
@@ -3,7 +3,7 @@
 When modifying the string constants files,
 please adhere to these guidelines:
 
-- All the entries in english-string-constants.ss have the same format
+- All the entries in english-string-constants.rkt have the same format
   (name string).  If the purpose of an entry you are adding to the
   file is not clear from just the name and string, put a comment next
   to the entry explaining what the string is going to be used for and
@@ -29,8 +29,8 @@ please adhere to these guidelines:
   re-use strings that already exist.  There's no need for yet another
   "Ok" string...
 
-- If you modify an existing string in english-string-constants.ss, go
-  through all the *-string-constants.ss files for the other languages,
+- If you modify an existing string in english-string-constants.rkt, go
+  through all the *-string-constants.rkt files for the other languages,
   comment out the old version of the modified string in each of these
   files, and put a short comment there telling us the English string
   has changed and needs to be re-translated.  Do not erase the old
@@ -72,7 +72,7 @@ please adhere to these guidelines:
 
 - If, for some reason, you really have to change the name of a string
   (like, because the original name you gave it really sucked...),
-  change the name of the string in *ALL* the *-string-constants.ss
+  change the name of the string in *ALL* the *-string-constants.rkt
   files.  That's a modification you can do without the help of a
   translator, so do it yourself.  It's not the job of the translators
   to clean up your naming mess for you.  Besides, you are the one who
@@ -81,14 +81,14 @@ please adhere to these guidelines:
 
 - If, for some reason, you need to remove a string (i.e. you changed
   your code and don't need the string anymore), remove the string in
-  *ALL* the *-string-constants.ss files.  Again, you don't need the
+  *ALL* the *-string-constants.rkt files.  Again, you don't need the
   help of a translator to do that.  If you're not sure whether you
   might need the string in the future or not, just comment it out in
   *ALL* the files.
 
 |#
 
-(module ukrainian-string-constants "string-constant-lang.ss"
+(module ukrainian-string-constants "string-constant-lang.rkt"
  ;;; when translating this constant, substitute name of actual langauge for `English'
  (is-this-your-native-language "Українська - це Ваша рідна мова?")
 
@@ -805,17 +805,17 @@ please adhere to these guidelines:
  (drscheme-internal-error "Внутрішня помилка DrRacket")
  
  ;;; tools
- (invalid-tool-spec "Некоректний файл info.ss, який містить опис інструменту в колекції ~a. Очікується рядок або непустий список рядків, отримано: ~e")
+ (invalid-tool-spec "Некоректний файл info.rkt, який містить опис інструменту в колекції ~a. Очікується рядок або непустий список рядків, отримано: ~e")
  (error-invoking-tool-title "Помилка виклику інструменту ~s;~s")
  (error-loading-tool-title "Помилка завантаження інструменту ~s\n~a") ;; ~s filled with a path, ~a filled with an error message from an exn
  (tool-tool-names-same-length
-  "В файлі info.ss для ~s очікується, що `tool-names' і `tools' - списки однакової довжини, отримано ~e і ~e")
+  "В файлі info.rkt для ~s очікується, що `tool-names' і `tools' - списки однакової довжини, отримано ~e і ~e")
  (tool-tool-icons-same-length
-  "В файлі info.ss для ~s очікується, що `tool-icons' і `tools' - списки однакової довжини, отримано ~e і ~e")
+  "В файлі info.rkt для ~s очікується, що `tool-icons' і `tools' - списки однакової довжини, отримано ~e і ~e")
  (tool-tool-urls-same-length
-  "В файлі info.ss для ~s очікується, що `tool-urls' і `tools' - списки однакової довжини, отримано ~e і ~e")
+  "В файлі info.rkt для ~s очікується, що `tool-urls' і `tools' - списки однакової довжини, отримано ~e і ~e")
  (error-getting-info-tool
-  "помилка при завантаженні файлу info.ss для ~s")
+  "помилка при завантаженні файлу info.rkt для ~s")
  (tool-error-phase1 "Помилка на 1 етапі для інструменту ~s; ~s")
  (tool-error-phase2 "Помилка на 2 етапі для інструменту ~s; ~s")
 
diff --git a/collects/swindle/tiny-clos.rkt b/collects/swindle/tiny-clos.rkt
index 1cb7f9b4b3..3a799860e5 100644
--- a/collects/swindle/tiny-clos.rkt
+++ b/collects/swindle/tiny-clos.rkt
@@ -285,7 +285,7 @@
 
 ;; This might be cute for some ugly hacks but not needed for now.
 ;; Copies the contents of source to target, making it an "alias" object.  This
-;; is no re-provided by clos.ss, but maybe it will in the future...
+;; is no re-provided by clos.rkt, but maybe it will in the future...
 ;; (define* (copy-object-contents! target source)
 ;;   (set-instance-class! target (instance-class source))
 ;;   (set-instance-proc!  target (instance-proc  source))
@@ -733,7 +733,7 @@
 ;;; optimize generic invocations: app-cache holds an 'equal hash-table that
 ;;; maps a list of classes to the lambda expression that holds the method call
 ;;; (it used to be an l-hash-table, but 'equal is ok since we can't compare
-;;; swindleobj instances recursively -- which is also why tool.ss needs to
+;;; swindleobj instances recursively -- which is also why tool.rkt needs to
 ;;; redefine the `render-value/format' method).  The contents of this slot is
 ;;; reset whenever a method is added to the generic.  Two problems make things
 ;;; a little more complicated.  First, if add-method is used to modify any of
@@ -1781,7 +1781,7 @@
 ;;; Make `add-method' a generic function
 
 ;;; Use this to compute a name for the method.  specs is a list of classes or
-;;; class-names (in case of unnamed-methods in clos.ss).
+;;; class-names (in case of unnamed-methods in clos.rkt).
 (define (compute-method-name specs generic-name)
   (define (spec-string spec)
     (cond [(%singleton? spec) (format "{~.s}" (singleton-value spec))]
diff --git a/collects/syntax/docprovide.rkt b/collects/syntax/docprovide.rkt
index 307a422c67..5ede56df3b 100644
--- a/collects/syntax/docprovide.rkt
+++ b/collects/syntax/docprovide.rkt
@@ -1,7 +1,6 @@
-
 (module docprovide scheme/base
   (require (for-syntax scheme/base
-                       "private/doctable.ss"))
+                       "private/doctable.rkt"))
 
   (define-syntaxes (provide-and-document provide-and-document/wrap)
     (let ()
diff --git a/collects/syntax/keyword.rkt b/collects/syntax/keyword.rkt
index 15c8334ea5..f3e3a60eb3 100644
--- a/collects/syntax/keyword.rkt
+++ b/collects/syntax/keyword.rkt
@@ -1,7 +1,7 @@
 #lang racket/base
 (require racket/contract/base
          racket/dict
-         "private/keyword.ss")
+         "private/keyword.rkt")
 
 (define optstx (or/c syntax? false/c))
 
diff --git a/collects/syntax/modcode.rkt b/collects/syntax/modcode.rkt
index 8fd9fd8c21..cae33f1117 100644
--- a/collects/syntax/modcode.rkt
+++ b/collects/syntax/modcode.rkt
@@ -1,7 +1,7 @@
 #lang racket/base
   (require mzlib/port
            racket/contract
-           "modread.ss")
+           "modread.rkt")
 
   (provide moddep-current-open-input-file
            exn:get-module-code
diff --git a/collects/syntax/modcollapse.rkt b/collects/syntax/modcollapse.rkt
index dfab94b126..7d58be9ee3 100644
--- a/collects/syntax/modcollapse.rkt
+++ b/collects/syntax/modcollapse.rkt
@@ -1,7 +1,7 @@
 #lang racket/base
 
 (require racket/contract/base
-         "private/modcollapse-noctc.ss")
+         "private/modcollapse-noctc.rkt")
 
 (define simple-rel-to-module-path-v/c
   (or/c (and/c module-path?
diff --git a/collects/syntax/moddep.rkt b/collects/syntax/moddep.rkt
index c399b6ed46..8bced1144b 100644
--- a/collects/syntax/moddep.rkt
+++ b/collects/syntax/moddep.rkt
@@ -1,14 +1,13 @@
-
 (module moddep mzscheme
-  (require "modread.ss"
-           "modcode.ss"
-           "modcollapse.ss"
-           "modresolve.ss")
+  (require "modread.rkt"
+           "modcode.rkt"
+           "modcollapse.rkt"
+           "modresolve.rkt")
 
-  (provide (all-from "modread.ss")
-           (all-from "modcode.ss")
-           (all-from "modcollapse.ss")
-           (all-from "modresolve.ss")
+  (provide (all-from "modread.rkt")
+           (all-from "modcode.rkt")
+           (all-from "modcollapse.rkt")
+           (all-from "modresolve.rkt")
            show-import-tree)
 
   (define (show-import-tree module-path)
diff --git a/collects/syntax/modresolve.rkt b/collects/syntax/modresolve.rkt
index 51da712840..3faaa9c638 100644
--- a/collects/syntax/modresolve.rkt
+++ b/collects/syntax/modresolve.rkt
@@ -1,6 +1,6 @@
 #lang racket/base
 (require racket/contract/base
-         "private/modhelp.ss")
+         "private/modhelp.rkt")
 
 (define (force-relto relto dir?)
   (cond [(path-string? relto)
diff --git a/collects/syntax/module-reader.rkt b/collects/syntax/module-reader.rkt
index 4105778ce7..737836a342 100644
--- a/collects/syntax/module-reader.rkt
+++ b/collects/syntax/module-reader.rkt
@@ -216,7 +216,7 @@
            #:read-spec
            [read-spec
             (lambda (in)
-              (let ([spec (regexp-try-match #px"^[ \t]+(.*?)(?=\\s|$)" in)]) ;; if this changes, the regexp in planet's lang/reader.ss must also change
+              (let ([spec (regexp-try-match #px"^[ \t]+(.*?)(?=\\s|$)" in)]) ;; if this changes, the regexp in planet's lang/reader.rkt must also change
                 (and spec (let ([s (cadr spec)])
                             (if (equal? s "") #f s)))))])
     (define (get in export-sym src line col pos spec-as-stx? mk-fail-thunk)
diff --git a/collects/syntax/parse/experimental/provide.rkt b/collects/syntax/parse/experimental/provide.rkt
index 43b435bdbf..d9aa6dd296 100644
--- a/collects/syntax/parse/experimental/provide.rkt
+++ b/collects/syntax/parse/experimental/provide.rkt
@@ -7,7 +7,7 @@
                      "../private/minimatch.rkt"
                      "../private/sc.rkt"
                      "../private/lib.rkt"
-                     "../private/rep-data.ss"
+                     "../private/rep-data.rkt"
                      "../private/kws.rkt"
                      unstable/wrapc))
 (provide provide-syntax-class/contract
diff --git a/collects/syntax/parse/experimental/splicing.rkt b/collects/syntax/parse/experimental/splicing.rkt
index 44276b6b3c..77d911e40e 100644
--- a/collects/syntax/parse/experimental/splicing.rkt
+++ b/collects/syntax/parse/experimental/splicing.rkt
@@ -1,6 +1,6 @@
 #lang racket/base
 (require (for-syntax racket/base
-                     "../../parse.ss"
+                     "../../parse.rkt"
                      "../private/rep-data.rkt"
                      "../private/kws.rkt")
          "../private/runtime.rkt")
diff --git a/collects/syntax/path-spec.rkt b/collects/syntax/path-spec.rkt
index ef614106f9..57ed3935c3 100644
--- a/collects/syntax/path-spec.rkt
+++ b/collects/syntax/path-spec.rkt
@@ -1,6 +1,6 @@
 (module path-spec scheme/base
   (require (for-template scheme/base))
-  (require "stx.ss")
+  (require "stx.rkt")
 
   (provide resolve-path-spec)
 
diff --git a/collects/syntax/private/modcollapse-noctc.rkt b/collects/syntax/private/modcollapse-noctc.rkt
index b7724c1806..64b86e9553 100644
--- a/collects/syntax/private/modcollapse-noctc.rkt
+++ b/collects/syntax/private/modcollapse-noctc.rkt
@@ -10,7 +10,7 @@ Use syntax/modcollapse instead.
 
 (require racket/string
          racket/list
-         "modhelp.ss")
+         "modhelp.rkt")
 
 (define (collapse-module-path s relto-mp)
   ;; relto-mp should be a path, '(lib relative-path collection) or symbol,
diff --git a/collects/syntax/private/template-runtime.rkt b/collects/syntax/private/template-runtime.rkt
index 89a1b95e6c..2b8a1b05a1 100644
--- a/collects/syntax/private/template-runtime.rkt
+++ b/collects/syntax/private/template-runtime.rkt
@@ -1,5 +1,5 @@
 #lang scheme/base
-(require "../stx.ss"
+(require "../stx.rkt"
          unstable/struct)
 
 (provide template-map-apply)
diff --git a/collects/syntax/struct.rkt b/collects/syntax/struct.rkt
index 9c55ae9776..f6de94d8da 100644
--- a/collects/syntax/struct.rkt
+++ b/collects/syntax/struct.rkt
@@ -1,9 +1,8 @@
-
 (module struct scheme/base
   (require (for-syntax scheme/base)
            mzlib/etc
            scheme/contract
-	   "stx.ss"
+           "stx.rkt"
            scheme/struct-info)
   (require (for-template mzscheme))
   
diff --git a/collects/syntax/template.rkt b/collects/syntax/template.rkt
index eb8d2798c2..c337397dea 100644
--- a/collects/syntax/template.rkt
+++ b/collects/syntax/template.rkt
@@ -1,8 +1,8 @@
 #lang scheme/base
-(require "stx.ss"
+(require "stx.rkt"
          unstable/struct
          (for-template scheme/base
-                       "private/template-runtime.ss"))
+                       "private/template-runtime.rkt"))
 
 (provide transform-template)
 
diff --git a/collects/syntax/toplevel.rkt b/collects/syntax/toplevel.rkt
index 46f2c10f23..dd278e6e41 100644
--- a/collects/syntax/toplevel.rkt
+++ b/collects/syntax/toplevel.rkt
@@ -1,9 +1,8 @@
-
 (module toplevel scheme/base
-  (require "kerncase.ss")
+  (require "kerncase.rkt")
   
   (provide eval-compile-time-part-of-top-level
-	   eval-compile-time-part-of-top-level/compile
+           eval-compile-time-part-of-top-level/compile
            expand-top-level-with-compile-time-evals
            expand-syntax-top-level-with-compile-time-evals
            expand-syntax-top-level-with-compile-time-evals/flatten)
diff --git a/collects/syntax/zodiac-unit.rkt b/collects/syntax/zodiac-unit.rkt
index cddec1f527..324bde51ba 100644
--- a/collects/syntax/zodiac-unit.rkt
+++ b/collects/syntax/zodiac-unit.rkt
@@ -4,9 +4,9 @@
 
 #lang scheme/unit
 
-(require "kerncase.ss"
-         "zodiac-sig.ss"
-         "stx.ss")
+(require "kerncase.rkt"
+         "zodiac-sig.rkt"
+         "stx.rkt")
 
 (import)
 (export zodiac^)
diff --git a/collects/syntax/zodiac.rkt b/collects/syntax/zodiac.rkt
index 12369862f4..aa79915e87 100644
--- a/collects/syntax/zodiac.rkt
+++ b/collects/syntax/zodiac.rkt
@@ -1,9 +1,8 @@
-
 (module zodiac mzscheme
   (require mzlib/unit)
 
-  (require "zodiac-sig.ss")
-  (require "zodiac-unit.ss")
+  (require "zodiac-sig.rkt"
+           "zodiac-unit.rkt")
 
   (define-values/invoke-unit/infer zodiac@)
 
diff --git a/collects/teachpack/2htdp/scribblings/shared.rkt b/collects/teachpack/2htdp/scribblings/shared.rkt
index 635b69dc12..ee23a8049d 100644
--- a/collects/teachpack/2htdp/scribblings/shared.rkt
+++ b/collects/teachpack/2htdp/scribblings/shared.rkt
@@ -1,5 +1,5 @@
 #lang scheme/base
 
-(require "../../htdp/scribblings/shared.ss")
+(require "../../htdp/scribblings/shared.rkt")
 
 (provide teachpack beginner-require)
diff --git a/collects/teachpack/info.ss b/collects/teachpack/info.rkt
similarity index 100%
rename from collects/teachpack/info.ss
rename to collects/teachpack/info.rkt
diff --git a/collects/test-box-recovery/info.rkt b/collects/test-box-recovery/info.rkt
index 1554e717c3..f8e813fb5d 100644
--- a/collects/test-box-recovery/info.rkt
+++ b/collects/test-box-recovery/info.rkt
@@ -2,7 +2,7 @@
 
 (define categories '(devtools))
 (define required-core-version "370")
-(define tools (list '("tool.ss")))
+(define tools (list '("tool.rkt")))
 (define tool-names (list "Test Box Recovery"))
 
 (define scribblings '(("test-box-recovery.scrbl" () (legacy))))
diff --git a/collects/test-engine/racket-gui.rkt b/collects/test-engine/racket-gui.rkt
index 2f92abc491..a9e2f12da9 100644
--- a/collects/test-engine/racket-gui.rkt
+++ b/collects/test-engine/racket-gui.rkt
@@ -4,7 +4,7 @@
            mzlib/pconvert mzlib/pretty
 	   (for-syntax scheme/base))
   
-  (require (except-in "scheme-tests.ss" test) "test-display.scm")
+  (require (except-in "scheme-tests.rkt" test) "test-display.scm")
   
   (define (make-formatter printer)
     (lambda (value)
@@ -54,6 +54,6 @@
              (printf "calling summarize-results method\n")
              (send test-info summarize-results (current-output-port))))))
   
-  (provide test format-value make-formatter (all-from-out "scheme-tests.ss"))
+  (provide test format-value make-formatter (all-from-out "scheme-tests.rkt"))
   
   )
diff --git a/collects/tests/data/queue.rkt b/collects/tests/data/queue.rkt
index 505123288f..1a306cd04f 100644
--- a/collects/tests/data/queue.rkt
+++ b/collects/tests/data/queue.rkt
@@ -3,7 +3,7 @@
 (require rackunit rackunit/text-ui data/queue)
 
 (run-tests
- (test-suite "queue.ss"
+ (test-suite "queue.rkt"
    (test-suite "queue-empty?"
      (test-case "make-queue"
        (check-true (queue-empty? (make-queue))))
diff --git a/collects/tests/drracket/time-keystrokes.rkt b/collects/tests/drracket/time-keystrokes.rkt
index a2c0fd9a33..c1e57b1017 100644
--- a/collects/tests/drracket/time-keystrokes.rkt
+++ b/collects/tests/drracket/time-keystrokes.rkt
@@ -55,7 +55,7 @@
                   (string->list chars)))
       
       
-      ;; copied from framework/test.ss
+      ;; copied from framework/test.rkt
       (define (send-key-event window event)
         (let loop ([l (ancestor-list window #t)])
           (cond [(null? l)
@@ -71,7 +71,7 @@
                 [(send (car l) on-subwindow-char window event) #f]
                 [else (loop (cdr l))])))
       
-      ;; copied from framework/test.ss
+      ;; copied from framework/test.rkt
       (define (ancestor-list window stop-at-top-level-window?)
         (let loop ([w window] [l null])
           (if (or (not w)
diff --git a/collects/tests/file/main.rkt b/collects/tests/file/main.rkt
index e924e1042f..4131b7a799 100644
--- a/collects/tests/file/main.rkt
+++ b/collects/tests/file/main.rkt
@@ -1,8 +1,8 @@
 #lang scheme/base
 
 (require tests/eli-tester
-         (prefix-in gzip: "gzip.ss")
-         (prefix-in md5:  "md5.ss"))
+         (prefix-in gzip: "gzip.rkt")
+         (prefix-in md5:  "md5.rkt"))
 
 (define (tests)
   (test do (begin (gzip:tests) (md5:tests))))
diff --git a/collects/tests/framework/canvas.rkt b/collects/tests/framework/canvas.rkt
index 3e4018b14f..a074a7ddc3 100644
--- a/collects/tests/framework/canvas.rkt
+++ b/collects/tests/framework/canvas.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-(require "test-suite-utils.ss")
+(require "test-suite-utils.rkt")
 
 (define (test-creation class name)
   (test
diff --git a/collects/tests/framework/exit.rkt b/collects/tests/framework/exit.rkt
index 0e93df9b99..9ba90a8de9 100644
--- a/collects/tests/framework/exit.rkt
+++ b/collects/tests/framework/exit.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-(require "test-suite-utils.ss")
+(require "test-suite-utils.rkt")
 
 (test 'exit/no-prompt
       (lambda (x)
diff --git a/collects/tests/framework/frame.rkt b/collects/tests/framework/frame.rkt
index 15ed81b15a..80837854cd 100644
--- a/collects/tests/framework/frame.rkt
+++ b/collects/tests/framework/frame.rkt
@@ -1,6 +1,6 @@
 #lang racket/base
 
-  (require "test-suite-utils.ss")
+  (require "test-suite-utils.rkt")
   
   (send-sexp-to-mred '(send (make-object frame:basic%
                               "dummy to keep from quitting")
diff --git a/collects/tests/framework/framework-test-engine.rkt b/collects/tests/framework/framework-test-engine.rkt
index 59eb3fca79..14f4015876 100644
--- a/collects/tests/framework/framework-test-engine.rkt
+++ b/collects/tests/framework/framework-test-engine.rkt
@@ -3,7 +3,7 @@
          racket/tcp
          racket/class
          racket/gui/base
-         "debug.ss")
+         "debug.rkt")
 
 (define errs null)
 (define sema (make-semaphore 1))
@@ -38,7 +38,7 @@
                                    (format "~s" x))))])
       (let ([port (call-with-input-file
                       (build-path (find-system-path 'temp-dir)
-                                  "framework-tests-receive-sexps-port.ss")
+                                  "framework-tests-receive-sexps-port.rkt")
                     read)])
         (debug-printf mr-tcp "about to connect to ~a\n" port)
         (let*-values ([(in out) (tcp-connect "127.0.0.1" port)])
diff --git a/collects/tests/framework/group-test.rkt b/collects/tests/framework/group-test.rkt
index 60dd18aa6e..1956729d02 100644
--- a/collects/tests/framework/group-test.rkt
+++ b/collects/tests/framework/group-test.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-(require "test-suite-utils.ss")
+(require "test-suite-utils.rkt")
 
 (define windows-menu-prefix 
   (let ([basics (list "Bring Frame to Front..." "Most Recent Window" 
diff --git a/collects/tests/framework/handler-test.rkt b/collects/tests/framework/handler-test.rkt
index 4f46987380..da8924cc16 100644
--- a/collects/tests/framework/handler-test.rkt
+++ b/collects/tests/framework/handler-test.rkt
@@ -1,7 +1,7 @@
 (module handler-test mzscheme
-  (require "test-suite-utils.ss")
+  (require "test-suite-utils.rkt")
 
-(let* ([filename "framework-group-test.ss"]
+(let* ([filename "framework-group-test.rkt"]
        [tmp-filename (build-path (find-system-path 'temp-dir) filename)])
 
   (test
diff --git a/collects/tests/framework/keys.rkt b/collects/tests/framework/keys.rkt
index 95953e4360..f6aded22df 100644
--- a/collects/tests/framework/keys.rkt
+++ b/collects/tests/framework/keys.rkt
@@ -1,6 +1,6 @@
 #lang racket/base
 
-(require "test-suite-utils.ss")
+(require "test-suite-utils.rkt")
   
   (test
    'keymap:aug-keymap%/get-table
diff --git a/collects/tests/framework/load.rkt b/collects/tests/framework/load.rkt
index d73d44e4cb..31af1247e1 100644
--- a/collects/tests/framework/load.rkt
+++ b/collects/tests/framework/load.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-(require "test-suite-utils.ss")
+(require "test-suite-utils.rkt")
 
   (load-framework-automatically #f)
 
@@ -21,20 +21,20 @@
             (void))))))
 
  
-  (test/load "gui-utils.ss" 'gui-utils:next-untitled-name)
-  (test/load "test.ss" 'test:run-interval)
-  (test/load "splash.ss" 'start-splash)
-  (test/load "framework-sig.ss" '(begin (eval '(require mzlib/unit))
+  (test/load "gui-utils.rkt" 'gui-utils:next-untitled-name)
+  (test/load "test.rkt" 'test:run-interval)
+  (test/load "splash.rkt" 'start-splash)
+  (test/load "framework-sig.rkt" '(begin (eval '(require mzlib/unit))
                                         (eval '(define-signature dummy-signature^ ((open framework^))))))
-  (test/load "framework-unit.ss" 'framework@)
-  (test/load "framework.ss" '(list test:button-push
-				   gui-utils:next-untitled-name
-				   frame:basic-mixin))
+  (test/load "framework-unit.rkt" 'framework@)
+  (test/load "framework.rkt" '(list test:button-push
+                                    gui-utils:next-untitled-name
+                                    frame:basic-mixin))
   
   ;; ensures that all of the names in the signature are provided
   ;; by (require framework)
-  (test/load 
-   "framework.ss"
+  (test/load
+   "framework.rkt"
    ;; these extra evals let me submit multiple, independent top-level
    ;; expressions in the newly created namespace.
    '(begin (eval '(require mzlib/unit))
diff --git a/collects/tests/framework/main.rkt b/collects/tests/framework/main.rkt
index ca6a207d43..fa6f65ce4e 100644
--- a/collects/tests/framework/main.rkt
+++ b/collects/tests/framework/main.rkt
@@ -2,8 +2,8 @@
 (require launcher
          racket/cmdline
          racket/unit
-         "debug.ss"
-         "test-suite-utils.ss")
+         "debug.rkt"
+         "test-suite-utils.rkt")
 
 (define preferences-file (find-system-path 'pref-file))
 
diff --git a/collects/tests/framework/mem.rkt b/collects/tests/framework/mem.rkt
index 47cd866314..8eab3fe890 100644
--- a/collects/tests/framework/mem.rkt
+++ b/collects/tests/framework/mem.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-(require "test-suite-utils.ss")
+(require "test-suite-utils.rkt")
 
 ; mem-boxes : (list-of (list string (list-of (weak-box TST))))
 (send-sexp-to-mred '(define mem-boxes null))
diff --git a/collects/tests/framework/panel-single.rkt b/collects/tests/framework/panel-single.rkt
index ee1936c190..cdf23b1aa7 100644
--- a/collects/tests/framework/panel-single.rkt
+++ b/collects/tests/framework/panel-single.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-(require "test-suite-utils.ss")
+(require "test-suite-utils.rkt")
 
 (test 
  'single-panel
diff --git a/collects/tests/framework/panel.rkt b/collects/tests/framework/panel.rkt
index aa1f5d4c74..dbadbdd699 100644
--- a/collects/tests/framework/panel.rkt
+++ b/collects/tests/framework/panel.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-(require "test-suite-utils.ss")
+(require "test-suite-utils.rkt")
 
 (test
  'dragable-min-size1
diff --git a/collects/tests/framework/pasteboard.rkt b/collects/tests/framework/pasteboard.rkt
index 9eea4590fc..f9b4382d0a 100644
--- a/collects/tests/framework/pasteboard.rkt
+++ b/collects/tests/framework/pasteboard.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-(require "test-suite-utils.ss")
+(require "test-suite-utils.rkt")
 
 (define (test-creation frame class name)
   (test
diff --git a/collects/tests/framework/prefs.rkt b/collects/tests/framework/prefs.rkt
index 4f41b09036..1313604361 100644
--- a/collects/tests/framework/prefs.rkt
+++ b/collects/tests/framework/prefs.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-(require "test-suite-utils.ss")
+(require "test-suite-utils.rkt")
   
   (define ((check-eq? x) y) (eq? x y))
   (define pref-sym 'plt:not-a-real-preference)
diff --git a/collects/tests/framework/scheme.rkt b/collects/tests/framework/scheme.rkt
index e9ca909b9f..bac60ad988 100644
--- a/collects/tests/framework/scheme.rkt
+++ b/collects/tests/framework/scheme.rkt
@@ -1,6 +1,6 @@
 #lang racket/base
 
-(require "test-suite-utils.ss")
+(require "test-suite-utils.rkt")
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;
diff --git a/collects/tests/framework/search.rkt b/collects/tests/framework/search.rkt
index bf636d1a80..ab2dc1e9ac 100644
--- a/collects/tests/framework/search.rkt
+++ b/collects/tests/framework/search.rkt
@@ -1,6 +1,6 @@
 #lang racket/base
 (require (for-syntax racket/base))
-(require "test-suite-utils.ss")
+(require "test-suite-utils.rkt")
 
 (define-syntax (test-search stx)
   (syntax-case stx ()
@@ -10,7 +10,7 @@
 
 (define (test-search/proc line txt string cs? rs bubble-table)
   (test
-   (string->symbol (format "search.ss: line ~a" line))
+   (string->symbol (format "search.rkt: line ~a" line))
    (lambda (x) (equal? bubble-table x))
    (lambda ()
      (queue-sexp-to-mred
diff --git a/collects/tests/framework/test-suite-utils.rkt b/collects/tests/framework/test-suite-utils.rkt
index 3802d8297a..67bb9c11fc 100644
--- a/collects/tests/framework/test-suite-utils.rkt
+++ b/collects/tests/framework/test-suite-utils.rkt
@@ -5,7 +5,7 @@
          racket/system
          racket/tcp
          racket/pretty
-         "debug.ss")
+         "debug.rkt")
 
 (provide
  test-name
@@ -60,7 +60,7 @@
 (define initial-port 6012)
 (define port-filename
   (build-path (find-system-path 'temp-dir)
-              "framework-tests-receive-sexps-port.ss"))
+              "framework-tests-receive-sexps-port.rkt"))
 
 (unless (file-exists? port-filename)
   (call-with-output-file port-filename
@@ -97,7 +97,7 @@
         (if (eq? 'windows (system-type)) "Racket.exe" "racket")))
       (path->string
        (build-path (collection-path "tests" "framework")
-                   "framework-test-engine.ss")))))
+                   "framework-test-engine.rkt")))))
   (debug-printf mz-tcp "accepting listener\n")
   (let-values ([(in out) (tcp-accept listener)])
     (set! in-port in)
diff --git a/collects/tests/framework/text.rkt b/collects/tests/framework/text.rkt
index ca34ae4ef6..7b07e9c02f 100644
--- a/collects/tests/framework/text.rkt
+++ b/collects/tests/framework/text.rkt
@@ -1,7 +1,7 @@
 #lang racket/base
 
 (require racket/file
-         "test-suite-utils.ss")
+         "test-suite-utils.rkt")
 
 (define dummy-frame-title "dummy to avoid quitting")
 (queue-sexp-to-mred `(send (make-object frame:basic% ,dummy-frame-title) show #t))
diff --git a/collects/tests/gracket/mem.rkt b/collects/tests/gracket/mem.rkt
index ae8d663ea8..8e0e0bf707 100644
--- a/collects/tests/gracket/mem.rkt
+++ b/collects/tests/gracket/mem.rkt
@@ -154,7 +154,7 @@
 	    (let ([e edit])
               (send e begin-edit-sequence)
 	      (when load-file?
-		(send e load-file (build-path source-dir "mem.ss")))
+		(send e load-file (build-path source-dir "mem.rkt")))
 	      (let loop ([i 20])
 		(send e insert (number->string i))
 		(unless (zero? i)
diff --git a/collects/tests/gracket/wxme.rkt b/collects/tests/gracket/wxme.rkt
index 65cd1f110f..47c2ad3348 100644
--- a/collects/tests/gracket/wxme.rkt
+++ b/collects/tests/gracket/wxme.rkt
@@ -12,7 +12,7 @@
          mred/private/wxme/editor
          mred/private/wxme/text
          mred/private/wxme/pasteboard
-         "test-editor-admin.ss"
+         "test-editor-admin.rkt"
          mred/private/wxme/stream
          mred/private/wxme/keymap
          mred/private/wxme/editor-snip
diff --git a/collects/tests/info.rkt b/collects/tests/info.rkt
index fb81880f48..dad6183fc4 100644
--- a/collects/tests/info.rkt
+++ b/collects/tests/info.rkt
@@ -1,7 +1,7 @@
 #lang setup/infotab
 
 (define name "Test Suites")
-(define tools '(("time-keystrokes.ss" "drracket")))
+(define tools '(("time-keystrokes.rkt" "drracket")))
 (define tool-names '("Time Keystrokes"))
 
 (define compile-omit-paths
diff --git a/collects/tests/macro-debugger/all-tests.rkt b/collects/tests/macro-debugger/all-tests.rkt
index f742952cf6..bba476891e 100644
--- a/collects/tests/macro-debugger/all-tests.rkt
+++ b/collects/tests/macro-debugger/all-tests.rkt
@@ -1,17 +1,17 @@
 #lang scheme/base
 (require rackunit
          macro-debugger/model/debug
-         "gentest-framework.ss"
-         "gentests.ss"
-         "test-setup.ss"
-         "tests/syntax-basic.ss"
-         "tests/syntax-macros.ss"
-         "tests/syntax-modules.ss"
-         "tests/syntax-errors.ss"
-         "tests/hiding.ss"
-         "tests/regression.ss"
-         "tests/policy.ss"
-         ;;"tests/collects.ss"
+         "gentest-framework.rkt"
+         "gentests.rkt"
+         "test-setup.rkt"
+         "tests/syntax-basic.rkt"
+         "tests/syntax-macros.rkt"
+         "tests/syntax-modules.rkt"
+         "tests/syntax-errors.rkt"
+         "tests/hiding.rkt"
+         "tests/regression.rkt"
+         "tests/policy.rkt"
+         ;;"tests/collects.rkt"
          )
 (provide all-tests)
 
diff --git a/collects/tests/macro-debugger/gentests.rkt b/collects/tests/macro-debugger/gentests.rkt
index add1446b42..4561a7b461 100644
--- a/collects/tests/macro-debugger/gentests.rkt
+++ b/collects/tests/macro-debugger/gentests.rkt
@@ -2,8 +2,8 @@
 (require rackunit)
 (require macro-debugger/model/debug
          macro-debugger/model/stx-util
-         "gentest-framework.ss"
-         "test-setup.ss")
+         "gentest-framework.rkt"
+         "test-setup.rkt")
 (provide mk-deriv-test
          mk-steps-test
          mk-hidden-deriv-test
diff --git a/collects/tests/macro-debugger/tests/hiding.rkt b/collects/tests/macro-debugger/tests/hiding.rkt
index 41780be436..9033101132 100644
--- a/collects/tests/macro-debugger/tests/hiding.rkt
+++ b/collects/tests/macro-debugger/tests/hiding.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 (require rackunit)
 (require macro-debugger/model/debug
-         "../test-setup.ss")
+         "../test-setup.rkt")
 (provide specialized-hiding-tests)
 
 ;; == Macro hiding
diff --git a/collects/tests/macro-debugger/tests/policy.rkt b/collects/tests/macro-debugger/tests/policy.rkt
index 2abc459904..27ef7bacac 100644
--- a/collects/tests/macro-debugger/tests/policy.rkt
+++ b/collects/tests/macro-debugger/tests/policy.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 (require rackunit)
 (require macro-debugger/model/debug
-         "../test-setup.ss")
+         "../test-setup.rkt")
 (provide policy-tests)
 
 (define ns (make-base-namespace))
diff --git a/collects/tests/macro-debugger/tests/regression.rkt b/collects/tests/macro-debugger/tests/regression.rkt
index 7e0883770d..8517fba241 100644
--- a/collects/tests/macro-debugger/tests/regression.rkt
+++ b/collects/tests/macro-debugger/tests/regression.rkt
@@ -2,7 +2,7 @@
 (require rackunit)
 (require macro-debugger/model/debug
          macro-debugger/model/steps
-         "../test-setup.ss")
+         "../test-setup.rkt")
 (provide regression-tests)
 
 (define regression-tests
@@ -116,7 +116,7 @@
     (test-case "hiding: keeping lifts in sync"
       (let ([freshname (gensym)])
         (eval `(module ,freshname mzscheme
-                 (require (lib "contract.ss"))
+                 (require (lib "contract.rkt"))
                  (provide/contract [f (integer? . -> . integer?)]
                                    [c integer?])
                  (define (f x) (add1 x))
diff --git a/collects/tests/macro-debugger/tests/syntax-basic.rkt b/collects/tests/macro-debugger/tests/syntax-basic.rkt
index 28027993b0..5e01601484 100644
--- a/collects/tests/macro-debugger/tests/syntax-basic.rkt
+++ b/collects/tests/macro-debugger/tests/syntax-basic.rkt
@@ -1,5 +1,5 @@
 #lang scheme/base
-(require "../gentest-framework.ss")
+(require "../gentest-framework.rkt")
 (provide proto:kernel-forms
          proto:kernel-contexts)
 
diff --git a/collects/tests/macro-debugger/tests/syntax-errors.rkt b/collects/tests/macro-debugger/tests/syntax-errors.rkt
index d51bfc3fbd..a2c2deb801 100644
--- a/collects/tests/macro-debugger/tests/syntax-errors.rkt
+++ b/collects/tests/macro-debugger/tests/syntax-errors.rkt
@@ -1,6 +1,5 @@
-
 #lang scheme/base
-(require "../gentest-framework.ss")
+(require "../gentest-framework.rkt")
 (provide proto:errors)
 
 (define-tests proto:errors "Bad syntax"
diff --git a/collects/tests/macro-debugger/tests/syntax-macros.rkt b/collects/tests/macro-debugger/tests/syntax-macros.rkt
index 8837463a1e..97599623a4 100644
--- a/collects/tests/macro-debugger/tests/syntax-macros.rkt
+++ b/collects/tests/macro-debugger/tests/syntax-macros.rkt
@@ -1,6 +1,5 @@
-
 #lang scheme/base
-(require "../gentest-framework.ss")
+(require "../gentest-framework.rkt")
 (provide proto:macros)
 
 (define-tests proto:macros "Macros"
diff --git a/collects/tests/macro-debugger/tests/syntax-modules.rkt b/collects/tests/macro-debugger/tests/syntax-modules.rkt
index b4db2d19a3..3297fe200b 100644
--- a/collects/tests/macro-debugger/tests/syntax-modules.rkt
+++ b/collects/tests/macro-debugger/tests/syntax-modules.rkt
@@ -1,6 +1,5 @@
-
 #lang scheme/base
-(require "../gentest-framework.ss")
+(require "../gentest-framework.rkt")
 (provide proto:modules)
 
 (define-syntax-rule (testM form . clauses)
@@ -327,9 +326,9 @@
           (P? (make-P P-x P-y))))
   (test "module with match"
         (module m mzscheme
-          (require (lib "match.ss"))
+          (require (lib "match.rkt"))
           (match '4 [n (add1 n)])))
   (test "module with match before require"
         (module m mzscheme
           (match '4 [n (add1 n)])
-          (require (lib "match.ss")))))
+          (require (lib "match.rkt")))))
diff --git a/collects/tests/match/match-tests.rkt b/collects/tests/match/match-tests.rkt
index 8eb873dc3c..c72a5b3b7f 100644
--- a/collects/tests/match/match-tests.rkt
+++ b/collects/tests/match/match-tests.rkt
@@ -117,11 +117,11 @@
                        (check = 3 (value))
                        (reset)
                        (check =  0 (value))))
-                     
+
      ))
-  
+
   (define match-tests
-    (test-suite "Tests for match.ss"
+    (test-suite "Tests for match.rkt"
                      doc-tests
                      simple-tests
                      nonlinear-tests
diff --git a/collects/tests/match/other-plt-tests.rkt b/collects/tests/match/other-plt-tests.rkt
index 8ca39c2723..57ae43a31f 100644
--- a/collects/tests/match/other-plt-tests.rkt
+++ b/collects/tests/match/other-plt-tests.rkt
@@ -35,7 +35,7 @@
   
   (define other-plt-tests 
     (test-suite 
-     "Tests copied from plt-match-test.ss"
+     "Tests copied from plt-match-test.rkt"
      
      (mytest (match "hello"
                ((pregexp (pregexp "hello")) #t)
diff --git a/collects/tests/match/other-tests.rkt b/collects/tests/match/other-tests.rkt
index f32005ae5e..b10f8c4f50 100644
--- a/collects/tests/match/other-tests.rkt
+++ b/collects/tests/match/other-tests.rkt
@@ -16,7 +16,7 @@
                        (check set-equal? tst exp))]))
   
   (define other-tests 
-    (test-suite "Tests copied from match-test.ss"
+    (test-suite "Tests copied from match-test.rkt"
 
 (mytest (letrec ((z 
                 (lambda (x) 
diff --git a/collects/tests/match/plt-match-tests.rkt b/collects/tests/match/plt-match-tests.rkt
index e42ec0f650..9a77411425 100644
--- a/collects/tests/match/plt-match-tests.rkt
+++ b/collects/tests/match/plt-match-tests.rkt
@@ -1,7 +1,8 @@
 #lang scheme/base
 
 (require (for-syntax scheme/base)
-         "match-tests.ss" "other-plt-tests.ss" "other-tests.ss" "examples.ss"
+         "match-tests.rkt" "other-plt-tests.rkt" "other-tests.rkt"
+         "examples.rkt"
          rackunit rackunit/text-ui)
 
 (require mzlib/plt-match)
@@ -364,7 +365,7 @@
                 (check = 1 b)))))
 
 (define plt-match-tests
-  (test-suite "Tests for plt-match.ss"
+  (test-suite "Tests for plt-match.rkt"
               doc-tests
               cons-tests
               simple-tests
diff --git a/collects/tests/net/head.rkt b/collects/tests/net/head.rkt
index 63df83896d..85c05f69d1 100644
--- a/collects/tests/net/head.rkt
+++ b/collects/tests/net/head.rkt
@@ -1,7 +1,7 @@
 #lang scheme
 (require net/head tests/eli-tester)
 
-;; a few tests of head.ss -- JBC, 2006-07-31
+;; a few tests of head.rkt -- JBC, 2006-07-31
 
 (provide tests)
 (define (tests)
diff --git a/collects/tests/plai/gc/bad-mutators/mut-1.rkt b/collects/tests/plai/gc/bad-mutators/mut-1.rkt
index 539786ee0a..f65b316abd 100644
--- a/collects/tests/plai/gc/bad-mutators/mut-1.rkt
+++ b/collects/tests/plai/gc/bad-mutators/mut-1.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../bad-collectors/broken-collector.ss" 12)
+(allocator-setup "../bad-collectors/broken-collector.rkt" 12)
 
 50
 60
diff --git a/collects/tests/plai/gc/bad-mutators/mutator2.rkt b/collects/tests/plai/gc/bad-mutators/mutator2.rkt
index 7ccce78833..c55f336206 100644
--- a/collects/tests/plai/gc/bad-mutators/mutator2.rkt
+++ b/collects/tests/plai/gc/bad-mutators/mutator2.rkt
@@ -1,2 +1,2 @@
 #lang plai/mutator
-(allocator-setup "../collectors/trivial-collector.ss" "y")
+(allocator-setup "../collectors/trivial-collector.rkt" "y")
diff --git a/collects/tests/plai/gc/bad-mutators/mutator5.rkt b/collects/tests/plai/gc/bad-mutators/mutator5.rkt
index e2f1b6c40b..7316851b96 100644
--- a/collects/tests/plai/gc/bad-mutators/mutator5.rkt
+++ b/collects/tests/plai/gc/bad-mutators/mutator5.rkt
@@ -1,2 +1,2 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/trivial-collector.ss")
+(allocator-setup "../good-collectors/trivial-collector.rkt")
diff --git a/collects/tests/plai/gc/bad-mutators/void-app.rkt b/collects/tests/plai/gc/bad-mutators/void-app.rkt
index af2f43b3d1..c1a80220e9 100644
--- a/collects/tests/plai/gc/bad-mutators/void-app.rkt
+++ b/collects/tests/plai/gc/bad-mutators/void-app.rkt
@@ -1,4 +1,4 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 100)
+(allocator-setup "../good-collectors/good-collector.rkt" 100)
 (define x (cons 1 2))
 ((set-first! x 2) 1)
diff --git a/collects/tests/plai/gc/good-mutators/andor.rkt b/collects/tests/plai/gc/good-mutators/andor.rkt
index 2fcfcffd2b..74c06d7f21 100644
--- a/collects/tests/plai/gc/good-mutators/andor.rkt
+++ b/collects/tests/plai/gc/good-mutators/andor.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 400)
+(allocator-setup "../good-collectors/good-collector.rkt" 400)
 (define (do-one i) (/ (- i 1)))
 (define (loop i)
   (or (= 1 i)
diff --git a/collects/tests/plai/gc/good-mutators/app.rkt b/collects/tests/plai/gc/good-mutators/app.rkt
index 0ec5037ae5..3038959241 100644
--- a/collects/tests/plai/gc/good-mutators/app.rkt
+++ b/collects/tests/plai/gc/good-mutators/app.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 28)
+(allocator-setup "../good-collectors/good-collector.rkt" 28)
 
 (define (app f)
   (lambda (x)
diff --git a/collects/tests/plai/gc/good-mutators/bindings.rkt b/collects/tests/plai/gc/good-mutators/bindings.rkt
index 2fa567a449..96c4e6224b 100644
--- a/collects/tests/plai/gc/good-mutators/bindings.rkt
+++ b/collects/tests/plai/gc/good-mutators/bindings.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 58)
+(allocator-setup "../good-collectors/good-collector.rkt" 58)
 
 (define x 'intial)
 (set! x 'final)
diff --git a/collects/tests/plai/gc/good-mutators/by-val.rkt b/collects/tests/plai/gc/good-mutators/by-val.rkt
index 10fd5ab0cf..35d54cb3c6 100644
--- a/collects/tests/plai/gc/good-mutators/by-val.rkt
+++ b/collects/tests/plai/gc/good-mutators/by-val.rkt
@@ -1,6 +1,6 @@
 ; Ensure that call by value is correctly implemented.
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 40)
+(allocator-setup "../good-collectors/good-collector.rkt" 40)
 
 (define global-val 'global)
 
diff --git a/collects/tests/plai/gc/good-mutators/case.rkt b/collects/tests/plai/gc/good-mutators/case.rkt
index bdf0266481..9497bc8aa2 100644
--- a/collects/tests/plai/gc/good-mutators/case.rkt
+++ b/collects/tests/plai/gc/good-mutators/case.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 40)
+(allocator-setup "../good-collectors/good-collector.rkt" 40)
 (test/value=? (case 1 [(1) 2])
               2)
 (test/value=? (case 1 [(1) 2] [else 3])
diff --git a/collects/tests/plai/gc/good-mutators/circular.rkt b/collects/tests/plai/gc/good-mutators/circular.rkt
index df26d99cc5..dd99eff806 100644
--- a/collects/tests/plai/gc/good-mutators/circular.rkt
+++ b/collects/tests/plai/gc/good-mutators/circular.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 68)
+(allocator-setup "../good-collectors/good-collector.rkt" 68)
 
 (define (gen-circular)
   (let ([x (cons 3 4)])
diff --git a/collects/tests/plai/gc/good-mutators/classic-error.rkt b/collects/tests/plai/gc/good-mutators/classic-error.rkt
index d1197725e7..24aea5acb3 100644
--- a/collects/tests/plai/gc/good-mutators/classic-error.rkt
+++ b/collects/tests/plai/gc/good-mutators/classic-error.rkt
@@ -1,6 +1,6 @@
 #lang plai/mutator
 ; This is `classic' in that it caught many bugs in copying collectors that students wrote for CS173, Fall 2007.
-(allocator-setup "../good-collectors/good-collector.ss" 28)
+(allocator-setup "../good-collectors/good-collector.rkt" 28)
 
 'trash
 'junk
diff --git a/collects/tests/plai/gc/good-mutators/closure-1.rkt b/collects/tests/plai/gc/good-mutators/closure-1.rkt
index 24249f6335..2dabb5d8bc 100644
--- a/collects/tests/plai/gc/good-mutators/closure-1.rkt
+++ b/collects/tests/plai/gc/good-mutators/closure-1.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 60)
+(allocator-setup "../good-collectors/good-collector.rkt" 60)
 
 (define lst '(2 -10)) ; (cons 2 (cons -10 empty)))
 
diff --git a/collects/tests/plai/gc/good-mutators/closure-2.rkt b/collects/tests/plai/gc/good-mutators/closure-2.rkt
index fe15f40b25..07e3890b02 100644
--- a/collects/tests/plai/gc/good-mutators/closure-2.rkt
+++ b/collects/tests/plai/gc/good-mutators/closure-2.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 40)
+(allocator-setup "../good-collectors/good-collector.rkt" 40)
 
 
 (define make-conser
diff --git a/collects/tests/plai/gc/good-mutators/cond.rkt b/collects/tests/plai/gc/good-mutators/cond.rkt
index 6a6b8ec1f0..ba9871c98a 100644
--- a/collects/tests/plai/gc/good-mutators/cond.rkt
+++ b/collects/tests/plai/gc/good-mutators/cond.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 40)
+(allocator-setup "../good-collectors/good-collector.rkt" 40)
 
 (cond
  [(zero? 3) 1111]
diff --git a/collects/tests/plai/gc/good-mutators/else.rkt b/collects/tests/plai/gc/good-mutators/else.rkt
index 281ef1a30b..92812c0076 100644
--- a/collects/tests/plai/gc/good-mutators/else.rkt
+++ b/collects/tests/plai/gc/good-mutators/else.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
 ; Is else defined?
-(allocator-setup "../good-collectors/good-collector.ss" 40)
+(allocator-setup "../good-collectors/good-collector.rkt" 40)
 
 (test/value=? (cond [else 28935723]) 28935723)
diff --git a/collects/tests/plai/gc/good-mutators/empty-mutator.rkt b/collects/tests/plai/gc/good-mutators/empty-mutator.rkt
index eab5348cbc..c4ca4ab497 100644
--- a/collects/tests/plai/gc/good-mutators/empty-mutator.rkt
+++ b/collects/tests/plai/gc/good-mutators/empty-mutator.rkt
@@ -1,3 +1,3 @@
 #lang plai/mutator
 
-(allocator-setup "../good-collectors/good-collector.ss" 80)
+(allocator-setup "../good-collectors/good-collector.rkt" 80)
diff --git a/collects/tests/plai/gc/good-mutators/gc-order.rkt b/collects/tests/plai/gc/good-mutators/gc-order.rkt
index fb4998f2fe..fecb8145a0 100644
--- a/collects/tests/plai/gc/good-mutators/gc-order.rkt
+++ b/collects/tests/plai/gc/good-mutators/gc-order.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 58)
+(allocator-setup "../good-collectors/good-collector.rkt" 58)
 
 (define x 3)
 (cons (begin (set! x 2)
diff --git a/collects/tests/plai/gc/good-mutators/global-roots.rkt b/collects/tests/plai/gc/good-mutators/global-roots.rkt
index 4a4b457461..408cc17c6a 100644
--- a/collects/tests/plai/gc/good-mutators/global-roots.rkt
+++ b/collects/tests/plai/gc/good-mutators/global-roots.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 20)
+(allocator-setup "../good-collectors/good-collector.rkt" 20)
 
 
 (define car first)
diff --git a/collects/tests/plai/gc/good-mutators/imports.rkt b/collects/tests/plai/gc/good-mutators/imports.rkt
index 173c91c9af..2d749d2b5a 100644
--- a/collects/tests/plai/gc/good-mutators/imports.rkt
+++ b/collects/tests/plai/gc/good-mutators/imports.rkt
@@ -1,7 +1,6 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 20)
+(allocator-setup "../good-collectors/good-collector.rkt" 20)
 
 (import-primitives modulo)
 
 (test/value=? (modulo 5 3) 2)
-
diff --git a/collects/tests/plai/gc/good-mutators/kathi-bug-1.rkt b/collects/tests/plai/gc/good-mutators/kathi-bug-1.rkt
index b68407f44f..1e33fcf950 100644
--- a/collects/tests/plai/gc/good-mutators/kathi-bug-1.rkt
+++ b/collects/tests/plai/gc/good-mutators/kathi-bug-1.rkt
@@ -1,4 +1,4 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 84)
+(allocator-setup "../good-collectors/good-collector.rkt" 84)
 (define L (cons 3 empty))
 (test/value=? L '(3))
diff --git a/collects/tests/plai/gc/good-mutators/mutator4.rkt b/collects/tests/plai/gc/good-mutators/mutator4.rkt
index 446885152d..2cd344cc0b 100644
--- a/collects/tests/plai/gc/good-mutators/mutator4.rkt
+++ b/collects/tests/plai/gc/good-mutators/mutator4.rkt
@@ -1,3 +1,3 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 100)
+(allocator-setup "../good-collectors/good-collector.rkt" 100)
 (cons 4 #t)
diff --git a/collects/tests/plai/gc/good-mutators/mutator6.rkt b/collects/tests/plai/gc/good-mutators/mutator6.rkt
index 313cc89cab..4039c2ded2 100644
--- a/collects/tests/plai/gc/good-mutators/mutator6.rkt
+++ b/collects/tests/plai/gc/good-mutators/mutator6.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 58)
+(allocator-setup "../good-collectors/good-collector.rkt" 58)
 
 (define x 'intial)
 (test/value=? x 'intial)
diff --git a/collects/tests/plai/gc/good-mutators/mutator7.rkt b/collects/tests/plai/gc/good-mutators/mutator7.rkt
index a921b692d2..4b0888d5ff 100644
--- a/collects/tests/plai/gc/good-mutators/mutator7.rkt
+++ b/collects/tests/plai/gc/good-mutators/mutator7.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 58)
+(allocator-setup "../good-collectors/good-collector.rkt" 58)
 
 (define x 'initial)
 
diff --git a/collects/tests/plai/gc/good-mutators/names.rkt b/collects/tests/plai/gc/good-mutators/names.rkt
index d9eec182ad..0a5ecf912e 100644
--- a/collects/tests/plai/gc/good-mutators/names.rkt
+++ b/collects/tests/plai/gc/good-mutators/names.rkt
@@ -1,3 +1,3 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 10)
+(allocator-setup "../good-collectors/good-collector.rkt" 10)
 (let ([f (λ (x) x)]) f)
diff --git a/collects/tests/plai/gc/good-mutators/proc-list.rkt b/collects/tests/plai/gc/good-mutators/proc-list.rkt
index 758d138204..35bfd39e97 100644
--- a/collects/tests/plai/gc/good-mutators/proc-list.rkt
+++ b/collects/tests/plai/gc/good-mutators/proc-list.rkt
@@ -2,7 +2,7 @@
 ; Demonstrates garbage collection while a closure is on the stack.  A correct collector must ensure that the roots
 ; reachable from (make-adder 90) and (make-adder 200) -- that is, the values 90 and 200 that k is bound to -- do
 ; not get discarded.
-(allocator-setup "../good-collectors/good-collector.ss" 58)
+(allocator-setup "../good-collectors/good-collector.rkt" 58)
 
 (define (make-adder k)
   (lambda (n) (+ n k)))
diff --git a/collects/tests/plai/gc/good-mutators/repeat-test.rkt b/collects/tests/plai/gc/good-mutators/repeat-test.rkt
index 0ecade0cf3..25a08bc68a 100644
--- a/collects/tests/plai/gc/good-mutators/repeat-test.rkt
+++ b/collects/tests/plai/gc/good-mutators/repeat-test.rkt
@@ -1,6 +1,6 @@
 #lang plai/mutator
 
-(allocator-setup "../good-collectors/good-collector.ss" 30)
+(allocator-setup "../good-collectors/good-collector.rkt" 30)
 
 (test/value=? (cons 1 empty) '(1))
 (test/value=? (cons 1 empty) '(1))
diff --git a/collects/tests/plai/gc/good-mutators/student-1.rkt b/collects/tests/plai/gc/good-mutators/student-1.rkt
index e8d4f19c9b..b7c31ecd57 100644
--- a/collects/tests/plai/gc/good-mutators/student-1.rkt
+++ b/collects/tests/plai/gc/good-mutators/student-1.rkt
@@ -1,6 +1,6 @@
 #lang plai/mutator
 
-; mark-and-sweep-test.ss - Ben Childs
+; mark-and-sweep-test.rkt - Ben Childs
 ; Designed to test the mark and sweep collector
 ; Runs three tests:
 ;
@@ -15,7 +15,7 @@
 ; Finally it runs the sample tests distributed with the assignment
 
 
-(allocator-setup "../good-collectors/good-collector.ss" 80)
+(allocator-setup "../good-collectors/good-collector.rkt" 80)
 
 ; Helper to generate long lists
 (define (gen-list x)
diff --git a/collects/tests/plai/gc/good-mutators/tail-calls.rkt b/collects/tests/plai/gc/good-mutators/tail-calls.rkt
index 7b78f23b0e..39b081ce22 100644
--- a/collects/tests/plai/gc/good-mutators/tail-calls.rkt
+++ b/collects/tests/plai/gc/good-mutators/tail-calls.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 68)
+(allocator-setup "../good-collectors/good-collector.rkt" 68)
 
 (define (length-accum lst len)
   (if (empty? lst)
diff --git a/collects/tests/plai/gc/good-mutators/test-framework.rkt b/collects/tests/plai/gc/good-mutators/test-framework.rkt
index 799993241d..5b928df3c2 100644
--- a/collects/tests/plai/gc/good-mutators/test-framework.rkt
+++ b/collects/tests/plai/gc/good-mutators/test-framework.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 28)
+(allocator-setup "../good-collectors/good-collector.rkt" 28)
 
 (halt-on-errors #t)
 (test/value=? 12 12)
diff --git a/collects/tests/plai/gc/good-mutators/thunks.rkt b/collects/tests/plai/gc/good-mutators/thunks.rkt
index 35331cceae..6c9f73ef88 100644
--- a/collects/tests/plai/gc/good-mutators/thunks.rkt
+++ b/collects/tests/plai/gc/good-mutators/thunks.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 4)
+(allocator-setup "../good-collectors/good-collector.rkt" 4)
 
 ; 2
 (define thunker
diff --git a/collects/tests/plai/gc/other-mutators/error.rkt b/collects/tests/plai/gc/other-mutators/error.rkt
index f807538bcc..d811c4825a 100644
--- a/collects/tests/plai/gc/other-mutators/error.rkt
+++ b/collects/tests/plai/gc/other-mutators/error.rkt
@@ -1,3 +1,3 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 400)
+(allocator-setup "../good-collectors/good-collector.rkt" 400)
 (error 'error "plai/mutator has error")
diff --git a/collects/tests/plai/gc/other-mutators/printing.rkt b/collects/tests/plai/gc/other-mutators/printing.rkt
index df36495a6c..611212d99d 100644
--- a/collects/tests/plai/gc/other-mutators/printing.rkt
+++ b/collects/tests/plai/gc/other-mutators/printing.rkt
@@ -1,5 +1,5 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 400)
+(allocator-setup "../good-collectors/good-collector.rkt" 400)
 (print-only-errors #f)
 
 (define lst (cons 1 (cons 2 (cons 3 empty))))
diff --git a/collects/tests/plai/gc/other-mutators/top.rkt b/collects/tests/plai/gc/other-mutators/top.rkt
index e6a117acbb..26ebad09e3 100644
--- a/collects/tests/plai/gc/other-mutators/top.rkt
+++ b/collects/tests/plai/gc/other-mutators/top.rkt
@@ -1,3 +1,3 @@
 #lang plai/mutator
-(allocator-setup "../good-collectors/good-collector.ss" 400)
+(allocator-setup "../good-collectors/good-collector.rkt" 400)
 frozzle
diff --git a/collects/tests/planet/cmdline-tool.rkt b/collects/tests/planet/cmdline-tool.rkt
index 3fa30ffd44..614c14cbf7 100644
--- a/collects/tests/planet/cmdline-tool.rkt
+++ b/collects/tests/planet/cmdline-tool.rkt
@@ -34,7 +34,7 @@ using 'system' to call out to the tool and then reading its results, etc.
     (get-output-string sp)))
 
 (unless (regexp-match #rx"No packages" (call-planet "show"))
-  (error 'cmdline-tool.ss "please clear out all planet packages before running this test"))
+  (error 'cmdline-tool.rkt "please clear out all planet packages before running this test"))
 
 (when (file-exists? test-connection.plt-cache)
   (delete-file test-connection.plt-cache))
@@ -52,10 +52,10 @@ using 'system' to call out to the tool and then reading its results, etc.
     [(regexp-match #rx"test-connection.plt" (call-planet "show"))
      (printf "Installed successfully\n")]
     [else
-     (error 'cmdline-tool.ss "Installation failed\n")])
+     (error 'cmdline-tool.rkt "Installation failed\n")])
   
   (unless (file-exists? test-connection.plt-cache)
-    (error 'cmdline-tool.ss "Installation did not populate ~s" test-connection.plt-cache)))
+    (error 'cmdline-tool.rkt "Installation did not populate ~s" test-connection.plt-cache)))
 
   
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -69,12 +69,12 @@ using 'system' to call out to the tool and then reading its results, etc.
   (printf "done\n")
   (cond
     [(regexp-match #rx"test-connection.plt" (call-planet "show"))
-     (error 'cmdline-tool.ss "Removal failed\n")]
+     (error 'cmdline-tool.rkt "Removal failed\n")]
     [else
      (printf "Removed successfully\n")])
   
   (unless (file-exists? test-connection.plt-cache)
-    (error 'cmdline-tool.ss "Removal removed ~s" test-connection.plt-cache)))
+    (error 'cmdline-tool.rkt "Removal removed ~s" test-connection.plt-cache)))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;
@@ -108,7 +108,7 @@ using 'system' to call out to the tool and then reading its results, etc.
   (printf "done\n")
   
   (unless (same-file? direct-file (list-ref test-connection-spec 1))
-    (error 'cmdline-tool.ss "expected planet fetch and planet url to point at the same file, but found different ones"))
+    (error 'cmdline-tool.rkt "expected planet fetch and planet url to point at the same file, but found different ones"))
   
   (delete-file direct-file)
   (printf "Download succesful\n"))
@@ -125,10 +125,10 @@ using 'system' to call out to the tool and then reading its results, etc.
   (apply call-planet "fileinject" test-connection-spec)
   (printf "done\n")
   (unless (regexp-match #rx"test-connection.plt" (call-planet "show"))
-    (error 'cmdline-tool.ss "expected a fileinject to show up in planet info"))
+    (error 'cmdline-tool.rkt "expected a fileinject to show up in planet info"))
   (apply call-planet "remove" test-connection-spec)
   (when (regexp-match #rx"test-connection.plt" (call-planet "show"))
-    (error 'cmdline-tool.ss "expected remove (after fileinject) to remove test-connection.plt"))
+    (error 'cmdline-tool.rkt "expected remove (after fileinject) to remove test-connection.plt"))
   (printf "Fileinject successful\n"))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -147,7 +147,7 @@ using 'system' to call out to the tool and then reading its results, etc.
       string<=?)))
   (define tmp-dir "test-connection-contents")
   (when (directory-exists? tmp-dir)
-      (error 'cmdline-tool.ss "expected the directory ~a to not exist" tmp-dir))
+      (error 'cmdline-tool.rkt "expected the directory ~a to not exist" tmp-dir))
   (call-planet "open" (list-ref test-connection-spec 1) tmp-dir)
   (define open-files
     (sort (let f/d-loop ([f/d #f]
@@ -182,12 +182,12 @@ using 'system' to call out to the tool and then reading its results, etc.
   (system (format "rm -rf ~a" tmp-dir))
   (printf "done\n")
   (unless (equal? open-files structure-files)
-    (error 'cmdline-tool.ss "expected planet structure to produce the same files as planet open, got ~s and ~s"
+    (error 'cmdline-tool.rkt "expected planet structure to produce the same files as planet open, got ~s and ~s"
            structure-files 
            open-files))
  
   (unless (equal? doc.txt-fetch doc.txt-print)
-    (error 'cmdline-tool.ss "expected planet print to produce the same content as the actual file, got\n~s\nand\n~s"
+    (error 'cmdline-tool.rkt "expected planet print to produce the same content as the actual file, got\n~s\nand\n~s"
            doc.txt-print
            doc.txt-fetch)))
     
@@ -272,7 +272,7 @@ using 'system' to call out to the tool and then reading its results, etc.
   
 (define (ensure-not-there fn)
   (when (file-exists? fn)
-    (error 'cmdline-tool.ss
+    (error 'cmdline-tool.rkt
            "test script expects no file named ~a to exist in the current directory (may have been left behind by test script, tho ... (which would be a bug))"
            fn)))
 
diff --git a/collects/tests/planet/lang.rkt b/collects/tests/planet/lang.rkt
index 51d8f80512..1baae6dd72 100644
--- a/collects/tests/planet/lang.rkt
+++ b/collects/tests/planet/lang.rkt
@@ -2,7 +2,7 @@
 
 (require planet/util
          scheme/runtime-path
-         "../eli-tester.ss")
+         "../eli-tester.rkt")
 
 (define-runtime-path here ".")
 (define (in-here path) (path->string (build-path here path)))
@@ -13,7 +13,7 @@
  (add-hard-link "plt" "dummy-package.plt" 1 0
                 (string->path (in-here "examples/dummy-package")))
  => (void)
- (dynamic-require `(file ,(in-here "examples/dummy-module.ss")) 'result)
+ (dynamic-require `(file ,(in-here "examples/dummy-module.rkt")) 'result)
  => '(successful test result)
  (remove-hard-link "plt" "dummy-package.plt" 1 0)
  => (void)
diff --git a/collects/tests/planet/version.rkt b/collects/tests/planet/version.rkt
index 644f619e5b..5d8ac058a2 100644
--- a/collects/tests/planet/version.rkt
+++ b/collects/tests/planet/version.rkt
@@ -14,7 +14,7 @@
 
 (define (test/proc file line got expected)
   (unless (equal? got expected)
-    (error 'test.ss "FAILED ~a: ~s\n     got ~s\nexpected ~s" file line got expected)))
+    (error 'test.rkt "FAILED ~a: ~s\n     got ~s\nexpected ~s" file line got expected)))
 
 
 (test (string->mz-version "372")
diff --git a/collects/tests/profile/main.rkt b/collects/tests/profile/main.rkt
index fd6a2e3849..27f939797f 100644
--- a/collects/tests/profile/main.rkt
+++ b/collects/tests/profile/main.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 
 (require tests/eli-tester profile/structs profile/analyzer
-         scheme/match scheme/list "topsort.ss")
+         scheme/match scheme/list "topsort.rkt")
 
 (define A '(A . #f))
 (define B '(B . #f))
diff --git a/collects/tests/profile/topsort.rkt b/collects/tests/profile/topsort.rkt
index edadb61e8b..e4f3f79392 100644
--- a/collects/tests/profile/topsort.rkt
+++ b/collects/tests/profile/topsort.rkt
@@ -96,7 +96,7 @@
                 '((A) (B)))
 
    ;; this is an example using the actual times for the A->B->A case that is
-   ;; tested in main.ss
+   ;; tested in main.rkt
    (same-levels '(* 2->1 A 1->2 B 2->1 A 1->2 *)
                 '((A) (B)))
 
diff --git a/collects/tests/racket/benchmarks/common/conform.rkt b/collects/tests/racket/benchmarks/common/conform.rkt
index aa05146346..29e844d1a1 100644
--- a/collects/tests/racket/benchmarks/common/conform.rkt
+++ b/collects/tests/racket/benchmarks/common/conform.rkt
@@ -1,2 +1 @@
-
-(module conform "wrap.ss" r5rs)
+(module conform "wrap.rkt" r5rs)
diff --git a/collects/tests/racket/benchmarks/common/cpstak.rkt b/collects/tests/racket/benchmarks/common/cpstak.rkt
index 8ca30fcf96..188aeda45f 100644
--- a/collects/tests/racket/benchmarks/common/cpstak.rkt
+++ b/collects/tests/racket/benchmarks/common/cpstak.rkt
@@ -1,2 +1 @@
-
-(module cpstak "wrap.ss")
+(module cpstak "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/ctak.rkt b/collects/tests/racket/benchmarks/common/ctak.rkt
index a5be89924f..abd6fe88fe 100644
--- a/collects/tests/racket/benchmarks/common/ctak.rkt
+++ b/collects/tests/racket/benchmarks/common/ctak.rkt
@@ -1,2 +1 @@
-
-(module ctak "wrap.ss")
+(module ctak "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/dderiv.rkt b/collects/tests/racket/benchmarks/common/dderiv.rkt
index 4913ebec5f..0cb5870fa7 100644
--- a/collects/tests/racket/benchmarks/common/dderiv.rkt
+++ b/collects/tests/racket/benchmarks/common/dderiv.rkt
@@ -1,2 +1 @@
-
-(module dderiv "wrap.ss")
+(module dderiv "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/deriv.rkt b/collects/tests/racket/benchmarks/common/deriv.rkt
index 31d2bcb067..a8ab984395 100644
--- a/collects/tests/racket/benchmarks/common/deriv.rkt
+++ b/collects/tests/racket/benchmarks/common/deriv.rkt
@@ -1,2 +1 @@
-
-(module deriv "wrap.ss")
+(module deriv "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/destruct.rkt b/collects/tests/racket/benchmarks/common/destruct.rkt
index 057e6ec9d7..75863aa5b4 100644
--- a/collects/tests/racket/benchmarks/common/destruct.rkt
+++ b/collects/tests/racket/benchmarks/common/destruct.rkt
@@ -1,2 +1 @@
-
-(module destruct "wrap.ss" r5rs)
+(module destruct "wrap.rkt" r5rs)
diff --git a/collects/tests/racket/benchmarks/common/div.rkt b/collects/tests/racket/benchmarks/common/div.rkt
index 018bdb14d8..8380e0979d 100644
--- a/collects/tests/racket/benchmarks/common/div.rkt
+++ b/collects/tests/racket/benchmarks/common/div.rkt
@@ -1,2 +1 @@
-
-(module div "wrap.ss")
+(module div "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/dynamic.rkt b/collects/tests/racket/benchmarks/common/dynamic.rkt
index 15a2da7011..9c9c6b9118 100644
--- a/collects/tests/racket/benchmarks/common/dynamic.rkt
+++ b/collects/tests/racket/benchmarks/common/dynamic.rkt
@@ -1,2 +1 @@
-
-(module dynamic "wrap.ss" r5rs)
+(module dynamic "wrap.rkt" r5rs)
diff --git a/collects/tests/racket/benchmarks/common/dynamic2.rkt b/collects/tests/racket/benchmarks/common/dynamic2.rkt
index 3bc71e6238..931c1093f2 100644
--- a/collects/tests/racket/benchmarks/common/dynamic2.rkt
+++ b/collects/tests/racket/benchmarks/common/dynamic2.rkt
@@ -1,2 +1 @@
-
-(module dynamic2 "wrap.ss")
+(module dynamic2 "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/earley.rkt b/collects/tests/racket/benchmarks/common/earley.rkt
index 8033ac2250..a54753a299 100644
--- a/collects/tests/racket/benchmarks/common/earley.rkt
+++ b/collects/tests/racket/benchmarks/common/earley.rkt
@@ -1,2 +1 @@
-
-(module earley "wrap.ss")
+(module earley "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/fft.rkt b/collects/tests/racket/benchmarks/common/fft.rkt
index ed81fa0266..febd3138f4 100644
--- a/collects/tests/racket/benchmarks/common/fft.rkt
+++ b/collects/tests/racket/benchmarks/common/fft.rkt
@@ -1,2 +1 @@
-
-(module fft "wrap.ss")
+(module fft "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/graphs.rkt b/collects/tests/racket/benchmarks/common/graphs.rkt
index 45d75d7458..693bfd7dc8 100644
--- a/collects/tests/racket/benchmarks/common/graphs.rkt
+++ b/collects/tests/racket/benchmarks/common/graphs.rkt
@@ -1,2 +1 @@
-
-(module graphs "wrap.ss")
+(module graphs "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/kanren.rkt b/collects/tests/racket/benchmarks/common/kanren.rkt
index 2778244b4a..0f5179568a 100644
--- a/collects/tests/racket/benchmarks/common/kanren.rkt
+++ b/collects/tests/racket/benchmarks/common/kanren.rkt
@@ -1,2 +1 @@
-
-(module kanren "wrap.ss")
+(module kanren "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/lattice.rkt b/collects/tests/racket/benchmarks/common/lattice.rkt
index 2394be43d7..811489fd03 100644
--- a/collects/tests/racket/benchmarks/common/lattice.rkt
+++ b/collects/tests/racket/benchmarks/common/lattice.rkt
@@ -1,2 +1 @@
-
-(module lattice "wrap.ss" r5rs)
+(module lattice "wrap.rkt" r5rs)
diff --git a/collects/tests/racket/benchmarks/common/lattice2.rkt b/collects/tests/racket/benchmarks/common/lattice2.rkt
index 96e746f367..ec70ebcc8a 100644
--- a/collects/tests/racket/benchmarks/common/lattice2.rkt
+++ b/collects/tests/racket/benchmarks/common/lattice2.rkt
@@ -1,2 +1 @@
-
-(module lattice2 "wrap.ss")
+(module lattice2 "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/maze.rkt b/collects/tests/racket/benchmarks/common/maze.rkt
index 1073c71769..d7f6d293f0 100644
--- a/collects/tests/racket/benchmarks/common/maze.rkt
+++ b/collects/tests/racket/benchmarks/common/maze.rkt
@@ -1,2 +1 @@
-
-(module maze "wrap.ss" r5rs)
+(module maze "wrap.rkt" r5rs)
diff --git a/collects/tests/racket/benchmarks/common/maze2.rkt b/collects/tests/racket/benchmarks/common/maze2.rkt
index 83fdc7cf51..d637bfe8d1 100644
--- a/collects/tests/racket/benchmarks/common/maze2.rkt
+++ b/collects/tests/racket/benchmarks/common/maze2.rkt
@@ -1,2 +1 @@
-
-(module maze2 "wrap.ss")
+(module maze2 "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/mazefun.rkt b/collects/tests/racket/benchmarks/common/mazefun.rkt
index 8c21660459..c9c11a7a81 100644
--- a/collects/tests/racket/benchmarks/common/mazefun.rkt
+++ b/collects/tests/racket/benchmarks/common/mazefun.rkt
@@ -1,2 +1 @@
-
-(module mazefun "wrap.ss")
+(module mazefun "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/nboyer.rkt b/collects/tests/racket/benchmarks/common/nboyer.rkt
index 2f3e901883..7e7007924c 100644
--- a/collects/tests/racket/benchmarks/common/nboyer.rkt
+++ b/collects/tests/racket/benchmarks/common/nboyer.rkt
@@ -1,2 +1 @@
-
-(module nboyer "wrap.ss")
+(module nboyer "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/nestedloop.rkt b/collects/tests/racket/benchmarks/common/nestedloop.rkt
index 5d7594bcdd..6c1217e873 100644
--- a/collects/tests/racket/benchmarks/common/nestedloop.rkt
+++ b/collects/tests/racket/benchmarks/common/nestedloop.rkt
@@ -1,2 +1 @@
-
-(module nestedloop "wrap.ss")
+(module nestedloop "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/nfa.rkt b/collects/tests/racket/benchmarks/common/nfa.rkt
index 1f9a6d657d..d18abb4dc8 100644
--- a/collects/tests/racket/benchmarks/common/nfa.rkt
+++ b/collects/tests/racket/benchmarks/common/nfa.rkt
@@ -1,2 +1 @@
-
-(module nfa "wrap.ss")
+(module nfa "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/nothing.rkt b/collects/tests/racket/benchmarks/common/nothing.rkt
index 1f7a80f8fe..73ff2072f6 100644
--- a/collects/tests/racket/benchmarks/common/nothing.rkt
+++ b/collects/tests/racket/benchmarks/common/nothing.rkt
@@ -1,2 +1 @@
-
-(module nothing "wrap.ss")
+(module nothing "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/nqueens.rkt b/collects/tests/racket/benchmarks/common/nqueens.rkt
index de43a29c50..ac8933d980 100644
--- a/collects/tests/racket/benchmarks/common/nqueens.rkt
+++ b/collects/tests/racket/benchmarks/common/nqueens.rkt
@@ -1,2 +1 @@
-
-(module nqueens "wrap.ss")
+(module nqueens "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/nucleic2.rkt b/collects/tests/racket/benchmarks/common/nucleic2.rkt
index 9e96273041..c4bf242dc1 100644
--- a/collects/tests/racket/benchmarks/common/nucleic2.rkt
+++ b/collects/tests/racket/benchmarks/common/nucleic2.rkt
@@ -1,2 +1 @@
-
-(module nucleic2 "wrap.ss")
+(module nucleic2 "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/nucleic3.rkt b/collects/tests/racket/benchmarks/common/nucleic3.rkt
index 19107cee51..8dc1384097 100644
--- a/collects/tests/racket/benchmarks/common/nucleic3.rkt
+++ b/collects/tests/racket/benchmarks/common/nucleic3.rkt
@@ -1,2 +1 @@
-
-(module nucleic3 "wrap.ss")
+(module nucleic3 "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/paraffins.rkt b/collects/tests/racket/benchmarks/common/paraffins.rkt
index e5c0de450c..c30f416101 100644
--- a/collects/tests/racket/benchmarks/common/paraffins.rkt
+++ b/collects/tests/racket/benchmarks/common/paraffins.rkt
@@ -1,2 +1 @@
-
-(module paraffins "wrap.ss")
+(module paraffins "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/peval.rkt b/collects/tests/racket/benchmarks/common/peval.rkt
index a8c13ef2d4..650d3decba 100644
--- a/collects/tests/racket/benchmarks/common/peval.rkt
+++ b/collects/tests/racket/benchmarks/common/peval.rkt
@@ -1,2 +1 @@
-
-(module peval "wrap.ss" r5rs)
+(module peval "wrap.rkt" r5rs)
diff --git a/collects/tests/racket/benchmarks/common/puzzle.rkt b/collects/tests/racket/benchmarks/common/puzzle.rkt
index c661a89e47..b2456716d7 100644
--- a/collects/tests/racket/benchmarks/common/puzzle.rkt
+++ b/collects/tests/racket/benchmarks/common/puzzle.rkt
@@ -1,2 +1 @@
-
-(module puzzle "wrap.ss")
+(module puzzle "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/ray.rkt b/collects/tests/racket/benchmarks/common/ray.rkt
index ecf94e4dba..f5ce742618 100644
--- a/collects/tests/racket/benchmarks/common/ray.rkt
+++ b/collects/tests/racket/benchmarks/common/ray.rkt
@@ -1,2 +1 @@
-
-(module ray "wrap.ss")
+(module ray "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/sboyer.rkt b/collects/tests/racket/benchmarks/common/sboyer.rkt
index d9f73bf479..726df16616 100644
--- a/collects/tests/racket/benchmarks/common/sboyer.rkt
+++ b/collects/tests/racket/benchmarks/common/sboyer.rkt
@@ -1,2 +1 @@
-
-(module sboyer "wrap.ss")
+(module sboyer "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/scheme.rkt b/collects/tests/racket/benchmarks/common/scheme.rkt
index ff7ef2a760..92598f692d 100644
--- a/collects/tests/racket/benchmarks/common/scheme.rkt
+++ b/collects/tests/racket/benchmarks/common/scheme.rkt
@@ -1,2 +1 @@
-
-(module scheme "wrap.ss" r5rs)
+(module scheme "wrap.rkt" r5rs)
diff --git a/collects/tests/racket/benchmarks/common/scheme2.rkt b/collects/tests/racket/benchmarks/common/scheme2.rkt
index ca1ee4a289..e4aed6209e 100644
--- a/collects/tests/racket/benchmarks/common/scheme2.rkt
+++ b/collects/tests/racket/benchmarks/common/scheme2.rkt
@@ -1,2 +1 @@
-
-(module scheme2 "wrap.ss")
+(module scheme2 "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/sort1.rkt b/collects/tests/racket/benchmarks/common/sort1.rkt
index 08c94c3d62..75d1d5119f 100644
--- a/collects/tests/racket/benchmarks/common/sort1.rkt
+++ b/collects/tests/racket/benchmarks/common/sort1.rkt
@@ -1,2 +1 @@
-
-(module sort1 "wrap.ss" r5rs)
+(module sort1 "wrap.rkt" r5rs)
diff --git a/collects/tests/racket/benchmarks/common/tak.rkt b/collects/tests/racket/benchmarks/common/tak.rkt
index bc4ec8d0a5..fa79dd8ae8 100644
--- a/collects/tests/racket/benchmarks/common/tak.rkt
+++ b/collects/tests/racket/benchmarks/common/tak.rkt
@@ -1,2 +1 @@
-
-(module tak "wrap.ss")
+(module tak "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/takl.rkt b/collects/tests/racket/benchmarks/common/takl.rkt
index 1023cb61ab..b871acb704 100644
--- a/collects/tests/racket/benchmarks/common/takl.rkt
+++ b/collects/tests/racket/benchmarks/common/takl.rkt
@@ -1,2 +1 @@
-
-(module takl "wrap.ss")
+(module takl "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/takr.rkt b/collects/tests/racket/benchmarks/common/takr.rkt
index 4c62598815..47575e7bc6 100644
--- a/collects/tests/racket/benchmarks/common/takr.rkt
+++ b/collects/tests/racket/benchmarks/common/takr.rkt
@@ -1,2 +1 @@
-
-(module takr "wrap.ss")
+(module takr "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/takr2.rkt b/collects/tests/racket/benchmarks/common/takr2.rkt
index 24c5898bab..ed20b4391c 100644
--- a/collects/tests/racket/benchmarks/common/takr2.rkt
+++ b/collects/tests/racket/benchmarks/common/takr2.rkt
@@ -1,2 +1 @@
-
-(module takr2 "wrap.ss")
+(module takr2 "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/common/triangle.rkt b/collects/tests/racket/benchmarks/common/triangle.rkt
index 322de72563..afe3e5428e 100644
--- a/collects/tests/racket/benchmarks/common/triangle.rkt
+++ b/collects/tests/racket/benchmarks/common/triangle.rkt
@@ -1,2 +1 @@
-
-(module triangle "wrap.ss")
+(module triangle "wrap.rkt")
diff --git a/collects/tests/racket/benchmarks/places/place-channel.rkt b/collects/tests/racket/benchmarks/places/place-channel.rkt
index ceb44f4b2c..995eabd736 100644
--- a/collects/tests/racket/benchmarks/places/place-channel.rkt
+++ b/collects/tests/racket/benchmarks/places/place-channel.rkt
@@ -55,9 +55,9 @@
        (place-channel-put ch fourk-b-message)))
   )
 END
-  "pct1.ss")
+  "pct1.rkt")
 
-  (let ([pl (dynamic-place "pct1.ss" 'place-main)])
+  (let ([pl (dynamic-place "pct1.rkt" 'place-main)])
     (define message-size (* 4024 1024))
     (define four-k-message (make-bytes message-size 65))
     (define count 150)
@@ -84,9 +84,9 @@ END
        (place-channel-put ch (place-channel-get ch))))
   )
 END
-  "pct1.ss")
+  "pct1.rkt")
 
-  (let ([pl (dynamic-place "pct1.ss" 'place-main)])
+  (let ([pl (dynamic-place "pct1.rkt" 'place-main)])
     (define tree (let loop ([depth 8])
       (if (depth . <= . 0)
         1
diff --git a/collects/tests/racket/benchmarks/places/place-launch.rkt b/collects/tests/racket/benchmarks/places/place-launch.rkt
index caeae3f557..aaf5a6c201 100644
--- a/collects/tests/racket/benchmarks/places/place-launch.rkt
+++ b/collects/tests/racket/benchmarks/places/place-launch.rkt
@@ -20,7 +20,7 @@
       (barrier ch))
   )
 END
-  "pct1.ss")
+  "pct1.rkt")
   (splat
   #<<END
   (module pct2 racket
@@ -36,7 +36,7 @@ END
       (barrier ch))
   )
 END
-  "pct2.ss")
+  "pct2.rkt")
 
   
   (define-values (plcnt reps symcnt)
@@ -62,8 +62,8 @@ END
       (barrier-m pls)
       (places-wait pls)))
 
-  (t "pct1.ss" "racket/base")
-  (t "pct2.ss" "racket")
+  (t "pct1.rkt" "racket/base")
+  (t "pct2.rkt" "racket")
 )
 
     
diff --git a/collects/tests/racket/benchmarks/places/symbols.rkt b/collects/tests/racket/benchmarks/places/symbols.rkt
index 57740c474a..b14c970692 100644
--- a/collects/tests/racket/benchmarks/places/symbols.rkt
+++ b/collects/tests/racket/benchmarks/places/symbols.rkt
@@ -26,14 +26,14 @@
 )]))
   )
 END
-  "pct1.ss")
+  "pct1.rkt")
 
   (define-values (plcnt reps symcnt)
     (match (current-command-line-arguments)
       [(vector) (values (processor-count) 10 1000000)]
       [(vector a b c) (values a b c)]))
 
-  (define pls (for/list ([i (in-range plcnt)]) (dynamic-place "pct1.ss" 'place-main)))
+  (define pls (for/list ([i (in-range plcnt)]) (dynamic-place "pct1.rkt" 'place-main)))
 
   (for ([i (in-range plcnt)]
         [pl pls])
@@ -60,7 +60,7 @@ END
             (barrier ch))
   )
 END
-  "pct2.ss")
+  "pct2.rkt")
 
   (define-values (plcnt reps symcnt)
     (match (current-command-line-arguments)
@@ -70,7 +70,7 @@ END
 
   (for ([j (in-range reps)])
     (time-n "require-algol-parse/racket-class" j
-      (define pls (for/list ([i (in-range plcnt)]) (dynamic-place "pct2.ss" 'place-main)))
+      (define pls (for/list ([i (in-range plcnt)]) (dynamic-place "pct2.rkt" 'place-main)))
       (barrier-m pls))))
 
 (symbol-test)
diff --git a/collects/tests/racket/benchmarks/rx/auto.rkt b/collects/tests/racket/benchmarks/rx/auto.rkt
index 939068eba2..f27445abe7 100755
--- a/collects/tests/racket/benchmarks/rx/auto.rkt
+++ b/collects/tests/racket/benchmarks/rx/auto.rkt
@@ -8,7 +8,7 @@ exec racket -qu "$0" ${1+"$@"}
            mzlib/port
            mzlib/list
            mzlib/date
-           "../common/cmdline.ss")
+           "../common/cmdline.rkt")
 
   ;; Needed for rxmzold, comment out otherwise:
   (begin
@@ -79,8 +79,8 @@ exec racket -qu "$0" ${1+"$@"}
         (* 1000 (read)))))
 
   (define (test-pcre input rx iterations)
-    (let ([pcregexp (dynamic-require "pcre.ss" 'pcregexp)]
-	  [pcregexp-match (dynamic-require "pcre.ss" 'pcregexp-match)])
+    (let ([pcregexp (dynamic-require "pcre.rkt" 'pcregexp)]
+	  [pcregexp-match (dynamic-require "pcre.rkt" 'pcregexp-match)])
       (let ([rx (pcregexp rx)])
 	(let ([start (current-inexact-milliseconds)])
 	  (let loop ([n iterations])
diff --git a/collects/tests/racket/embed-planet-1/alt.rkt b/collects/tests/racket/embed-planet-1/alt.rkt
index 197192d70e..abb8992b46 100644
--- a/collects/tests/racket/embed-planet-1/alt.rkt
+++ b/collects/tests/racket/embed-planet-1/alt.rkt
@@ -1,5 +1,5 @@
 #lang racket/base
-(require "main.ss")
+(require "main.rkt")
 
 (with-output-to-file "stdout"
   #:exists 'append
diff --git a/collects/tests/srfi/1/alist-test.rkt b/collects/tests/srfi/1/alist-test.rkt
index a2b87d8586..4bb0dfd13c 100644
--- a/collects/tests/srfi/1/alist-test.rkt
+++ b/collects/tests/srfi/1/alist-test.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <alist-test.ss> ---- Association list tests
+;;; <alist-test.rkt> ---- Association list tests
 ;;; Time-stamp: <2008-03-07 16:36:15 nhw>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -305,4 +305,4 @@
      ))
   )
 
-;;; alist-test.ss ends here
+;;; alist-test.rkt ends here
diff --git a/collects/tests/srfi/1/all-1-tests.rkt b/collects/tests/srfi/1/all-1-tests.rkt
index 31a3daf77b..057e407578 100644
--- a/collects/tests/srfi/1/all-1-tests.rkt
+++ b/collects/tests/srfi/1/all-1-tests.rkt
@@ -1,16 +1,16 @@
 (module all-1-tests mzscheme
   
   (require rackunit)
-  (require "alist-test.ss"
-           "cons-test.ss"
-           "delete-test.ss"
-           "filter-test.ss"
-           "fold-test.ss"
-           "lset-test.ss"
-           "misc-test.ss"
-           "predicate-test.ss"
-           "search-test.ss"
-           "selector-test.ss")
+  (require "alist-test.rkt"
+           "cons-test.rkt"
+           "delete-test.rkt"
+           "filter-test.rkt"
+           "fold-test.rkt"
+           "lset-test.rkt"
+           "misc-test.rkt"
+           "predicate-test.rkt"
+           "search-test.rkt"
+           "selector-test.rkt")
   
   (provide all-1-tests)
   
diff --git a/collects/tests/srfi/1/cons-test.rkt b/collects/tests/srfi/1/cons-test.rkt
index 61aa2a3ac0..eccb6f75b3 100644
--- a/collects/tests/srfi/1/cons-test.rkt
+++ b/collects/tests/srfi/1/cons-test.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <cons-test.ss> ---- List constructor tests
+;;; <cons-test.rkt> ---- List constructor tests
 ;;; Time-stamp: <05/12/16 21:14:31 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -214,4 +214,4 @@
 
      ))
   )
-;;; cons-test.ss ends here
+;;; cons-test.rkt ends here
diff --git a/collects/tests/srfi/1/delete-test.rkt b/collects/tests/srfi/1/delete-test.rkt
index 90297e8a69..1f74c41adc 100644
--- a/collects/tests/srfi/1/delete-test.rkt
+++ b/collects/tests/srfi/1/delete-test.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <delete-test.ss> ---- List deletion function tests
+;;; <delete-test.rkt> ---- List deletion function tests
 ;;; Time-stamp: <05/12/16 21:16:28 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -355,4 +355,4 @@
      ))
 
   )
-;;; delete-test.ss ends here
+;;; delete-test.rkt ends here
diff --git a/collects/tests/srfi/1/filter-test.rkt b/collects/tests/srfi/1/filter-test.rkt
index c7eff01d01..c0f8f2bd97 100644
--- a/collects/tests/srfi/1/filter-test.rkt
+++ b/collects/tests/srfi/1/filter-test.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <filter-test.ss> ---- List filtering and partitioning tests
+;;; <filter-test.rkt> ---- List filtering and partitioning tests
 ;;; Time-stamp: <05/12/16 21:16:28 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -270,4 +270,4 @@
      ))
   )
 
-;;; filter-test.ss ends here
+;;; filter-test.rkt ends here
diff --git a/collects/tests/srfi/1/fold-test.rkt b/collects/tests/srfi/1/fold-test.rkt
index 1b277f3d4d..63d9a5db49 100644
--- a/collects/tests/srfi/1/fold-test.rkt
+++ b/collects/tests/srfi/1/fold-test.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <fold-test.ss> ---- Tests for list folds
+;;; <fold-test.rkt> ---- Tests for list folds
 ;;; Time-stamp: <05/12/16 21:19:37 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -953,4 +953,4 @@
 
      ))
   )
-;;; fold-test.ss ends here
+;;; fold-test.rkt ends here
diff --git a/collects/tests/srfi/1/lset-test.rkt b/collects/tests/srfi/1/lset-test.rkt
index 75592ba274..6e08cdb319 100644
--- a/collects/tests/srfi/1/lset-test.rkt
+++ b/collects/tests/srfi/1/lset-test.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <lset-test.ss> ---- Lists as Sets Tests
+;;; <lset-test.rkt> ---- Lists as Sets Tests
 ;;; Time-stamp: <05/12/16 21:15:22 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -108,4 +108,4 @@
                           '(d c b i o u))))
      ))
   )
-;;; lset-test.ss ends here
+;;; lset-test.rkt ends here
diff --git a/collects/tests/srfi/1/misc-test.rkt b/collects/tests/srfi/1/misc-test.rkt
index 427ac4503d..6a2a7c5a50 100644
--- a/collects/tests/srfi/1/misc-test.rkt
+++ b/collects/tests/srfi/1/misc-test.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <misc-test.ss> ---- Misc list procedure tests
+;;; <misc-test.rkt> ---- Misc list procedure tests
 ;;; Time-stamp: <05/12/16 21:15:50 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -379,4 +379,4 @@
      ))
   )
 
-;;; misc-test.ss ends here
+;;; misc-test.rkt ends here
diff --git a/collects/tests/srfi/1/predicate-test.rkt b/collects/tests/srfi/1/predicate-test.rkt
index e85fa12e65..3effc3ad84 100644
--- a/collects/tests/srfi/1/predicate-test.rkt
+++ b/collects/tests/srfi/1/predicate-test.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <predicate-test.ss> ---- List predicate tests
+;;; <predicate-test.rkt> ---- List predicate tests
 ;;; Time-stamp: <05/12/16 21:16:27 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -165,4 +165,4 @@
 
      ))
   )
-;;; predicate-test.ss ends here
+;;; predicate-test.rkt ends here
diff --git a/collects/tests/srfi/1/search-test.rkt b/collects/tests/srfi/1/search-test.rkt
index 6eec8905a3..e06cf33cf9 100644
--- a/collects/tests/srfi/1/search-test.rkt
+++ b/collects/tests/srfi/1/search-test.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <search-test.ss> ---- List searching functions tests
+;;; <search-test.rkt> ---- List searching functions tests
 ;;; Time-stamp: <05/12/16 21:16:26 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -526,4 +526,4 @@
      ))
   )
 
-;;; search-test.ss ends here
+;;; search-test.rkt ends here
diff --git a/collects/tests/srfi/1/selector-test.rkt b/collects/tests/srfi/1/selector-test.rkt
index bf4e3fcb41..7226e0be84 100644
--- a/collects/tests/srfi/1/selector-test.rkt
+++ b/collects/tests/srfi/1/selector-test.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <selector-test.ss> ---- List selector tests
+;;; <selector-test.rkt> ---- List selector tests
 ;;; Time-stamp: <05/12/16 21:13:25 noel>
 ;;;
 ;;; Copyright (C) 2002 by Noel Welsh.
@@ -338,4 +338,4 @@
      ))
   )
 
-;;; selector-test.ss ends here
+;;; selector-test.rkt ends here
diff --git a/collects/tests/srfi/13/string-test.rkt b/collects/tests/srfi/13/string-test.rkt
index 4e6e77078b..e24eeeb513 100644
--- a/collects/tests/srfi/13/string-test.rkt
+++ b/collects/tests/srfi/13/string-test.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <string-test.ss> ---- SRFI-13 (string) tests
+;;; <string-test.rkt> ---- SRFI-13 (string) tests
 ;;; Time-stamp: <06/06/09 16:05:08 nhw>
 ;;;
 ;;; Copyright (C) 2002 by Francisco Solsona. 
@@ -79,4 +79,4 @@
 
   )
 
-;;; string-test.ss ends here
+;;; string-test.rkt ends here
diff --git a/collects/tests/srfi/14/char-set-test.rkt b/collects/tests/srfi/14/char-set-test.rkt
index f04abd813c..ad61059f16 100644
--- a/collects/tests/srfi/14/char-set-test.rkt
+++ b/collects/tests/srfi/14/char-set-test.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <char-set-test.ss> ---- Test driver for the SRFI-14 port: char-set
+;;; <char-set-test.rkt> ---- Test driver for the SRFI-14 port: char-set
 ;;; Time-stamp: <06/06/09 16:38:25 nhw>
 ;;;
 ;;; Copyright (C) 2002 by Francisco Solsona.
@@ -233,4 +233,4 @@
 
   )
 
-;;; char-set-test.ss ends here
+;;; char-set-test.rkt ends here
diff --git a/collects/tests/srfi/2/and-let-test.rkt b/collects/tests/srfi/2/and-let-test.rkt
index 89c8df5868..430925bbde 100644
--- a/collects/tests/srfi/2/and-let-test.rkt
+++ b/collects/tests/srfi/2/and-let-test.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <and-let-test.ss> ---- and-let* macro tests
+;;; <and-let-test.rkt> ---- and-let* macro tests
 ;;; Time-stamp: <06/06/09 15:58:59 nhw>
 ;;;
 ;;; Copyright (C) 2002 by Francisco Solsona. 
@@ -191,4 +191,4 @@
     
 
 
-;;; and-let-test.ss ends here
+;;; and-let-test.rkt ends here
diff --git a/collects/tests/srfi/26/cut-test.rkt b/collects/tests/srfi/26/cut-test.rkt
index 551448df60..ce9d4a96f0 100644
--- a/collects/tests/srfi/26/cut-test.rkt
+++ b/collects/tests/srfi/26/cut-test.rkt
@@ -1,5 +1,5 @@
 ;;;
-;;; <cut-test.ss> ---- SRFI 26 tests
+;;; <cut-test.rkt> ---- SRFI 26 tests
 ;;; Time-stamp: <06/06/09 16:04:14 nhw>
 ;;;
 ;;; Usually, I would add a copyright notice, and the announce that
@@ -20,7 +20,7 @@
 ;     SRFI-23: error
 ;
 
-; $Id: cut-test.ss,v 1.1 2002/06/20 15:40:52 noel Exp $
+; $Id: cut-test.rkt,v 1.1 2002/06/20 15:40:52 noel Exp $
 
 (module cut-test mzscheme
   (require rackunit)
diff --git a/collects/tests/srfi/43/all-srfi-43-tests.rkt b/collects/tests/srfi/43/all-srfi-43-tests.rkt
index e32ffd1f10..73004b9d0d 100644
--- a/collects/tests/srfi/43/all-srfi-43-tests.rkt
+++ b/collects/tests/srfi/43/all-srfi-43-tests.rkt
@@ -1,11 +1,11 @@
 (module all-srfi-43-tests mzscheme
   (require rackunit)
-  (require "constructor-tests.ss"
-           "predicate-tests.ss"
-           "iteration-tests.ss"
-           "searching-tests.ss"
-           "mutator-tests.ss"
-           "conversion-tests.ss")
+  (require "constructor-tests.rkt"
+           "predicate-tests.rkt"
+           "iteration-tests.rkt"
+           "searching-tests.rkt"
+           "mutator-tests.rkt"
+           "conversion-tests.rkt")
   (provide all-srfi-43-tests)
   
   (define all-srfi-43-tests
diff --git a/collects/tests/srfi/all-srfi-tests.rkt b/collects/tests/srfi/all-srfi-tests.rkt
index 104ccd1e3f..12933bf9cd 100644
--- a/collects/tests/srfi/all-srfi-tests.rkt
+++ b/collects/tests/srfi/all-srfi-tests.rkt
@@ -1,15 +1,15 @@
 (module all-srfi-tests mzscheme
   
   (require rackunit)
-  (require "1/all-1-tests.ss"
-           "2/and-let-test.ss"
-           "4/srfi-4-test.ss"
-           "13/string-test.ss"
-           "14/char-set-test.ss"
-           "26/cut-test.ss"
-           "40/all-srfi-40-tests.ss"
-           "43/all-srfi-43-tests.ss"
-           "69/hash-tests.ss")
+  (require "1/all-1-tests.rkt"
+           "2/and-let-test.rkt"
+           "4/srfi-4-test.rkt"
+           "13/string-test.rkt"
+           "14/char-set-test.rkt"
+           "26/cut-test.rkt"
+           "40/all-srfi-40-tests.rkt"
+           "43/all-srfi-43-tests.rkt"
+           "69/hash-tests.rkt")
   (provide all-srfi-tests)
   
   (define all-srfi-tests
diff --git a/collects/tests/srfi/run-tests.rkt b/collects/tests/srfi/run-tests.rkt
index 6d2feb1110..e837af627b 100644
--- a/collects/tests/srfi/run-tests.rkt
+++ b/collects/tests/srfi/run-tests.rkt
@@ -2,6 +2,6 @@
 
 (require rackunit)
 (require rackunit/text-ui)
-(require "all-srfi-tests.ss")
+(require "all-srfi-tests.rkt")
 
 (run-tests all-srfi-tests)
diff --git a/collects/tests/stepper/automatic-tests.rkt b/collects/tests/stepper/automatic-tests.rkt
index 542737e6e9..b5e06edd8f 100644
--- a/collects/tests/stepper/automatic-tests.rkt
+++ b/collects/tests/stepper/automatic-tests.rkt
@@ -5,8 +5,8 @@
 (require "shared-unit-tests.rkt")
 
 ;; now, the rest:
-(require "through-tests.ss" 
-         "test-engine.ss")
+(require "through-tests.rkt" 
+         "test-engine.rkt")
 
 (define lazy-tests 
   '(lazy1 lazy2 lazy3 lazy-multi lazy-app1 lazy-app2 lazy-app3 
diff --git a/collects/tests/stepper/test-cases.rkt b/collects/tests/stepper/test-cases.rkt
index 5d477d3d0f..ceee9b7010 100644
--- a/collects/tests/stepper/test-cases.rkt
+++ b/collects/tests/stepper/test-cases.rkt
@@ -1,7 +1,7 @@
 #lang racket
 
 (require "test-abbrev.rkt"
-         (prefix-in m: "language-level-model.ss")
+         (prefix-in m: "language-level-model.rkt")
          stepper/private/model-settings)
 
 (provide the-test-cases)
diff --git a/collects/tests/stepper/test-engine.rkt b/collects/tests/stepper/test-engine.rkt
index 5d244927ca..8cab719a64 100644
--- a/collects/tests/stepper/test-engine.rkt
+++ b/collects/tests/stepper/test-engine.rkt
@@ -6,7 +6,7 @@
          lang/run-teaching-program
          (only-in srfi/13 string-contains)
          scheme/contract
-         "language-level-model.ss")
+         "language-level-model.rkt")
 
 
 ;; A SIMPLE EXAMPLE OF USING THIS FRAMEWORK:
diff --git a/collects/tests/stepper/through-tests.rkt b/collects/tests/stepper/through-tests.rkt
index 103e5632f4..63f80234b1 100755
--- a/collects/tests/stepper/through-tests.rkt
+++ b/collects/tests/stepper/through-tests.rkt
@@ -1,8 +1,8 @@
 #lang racket
 
 (require (only-in stepper/private/model stepper-model-debug?)
-         (prefix-in m: "language-level-model.ss")
-         "test-engine.ss"
+         (prefix-in m: "language-level-model.rkt")
+         "test-engine.rkt"
          "test-cases.rkt"
          
          ;; for xml testing:
diff --git a/collects/tests/typed-scheme/main.rkt b/collects/tests/typed-scheme/main.rkt
index b3a7a32201..596e285b69 100644
--- a/collects/tests/typed-scheme/main.rkt
+++ b/collects/tests/typed-scheme/main.rkt
@@ -4,8 +4,8 @@
          mzlib/etc scheme/port
          compiler/compiler
          scheme/match mzlib/compile
-         "unit-tests/all-tests.ss"
-         "unit-tests/test-utils.ss"
+         "unit-tests/all-tests.rkt"
+         "unit-tests/test-utils.rkt"
          "optimizer/run.rkt")
 
 (define (scheme-file? s)
diff --git a/collects/tests/typed-scheme/nightly-run.rkt b/collects/tests/typed-scheme/nightly-run.rkt
index cc2059d7b9..d4798e5a07 100644
--- a/collects/tests/typed-scheme/nightly-run.rkt
+++ b/collects/tests/typed-scheme/nightly-run.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
 
 (require scheme/runtime-path)
-(define-runtime-path run "run.ss")
+(define-runtime-path run "run.rkt")
 (if (eq? 'cgc (system-type 'gc))
   (printf "Running under CGC => skipping tests\n")
   (parameterize ([current-command-line-arguments '#("--nightly")])
diff --git a/collects/tests/typed-scheme/run.rkt b/collects/tests/typed-scheme/run.rkt
index a6123e4f4b..84d94c6f06 100644
--- a/collects/tests/typed-scheme/run.rkt
+++ b/collects/tests/typed-scheme/run.rkt
@@ -1,7 +1,7 @@
 #lang racket
 (require racket/vector racket/gui/dynamic rackunit)
 
-(require "main.ss")
+(require "main.rkt")
 
 (define exec (make-parameter go/text))
 (define nightly? (make-parameter #f))
diff --git a/collects/tests/typed-scheme/succeed/foldo.rkt b/collects/tests/typed-scheme/succeed/foldo.rkt
index c2c2b33f17..9450b9d421 100644
--- a/collects/tests/typed-scheme/succeed/foldo.rkt
+++ b/collects/tests/typed-scheme/succeed/foldo.rkt
@@ -1,5 +1,5 @@
 (module foldo mzscheme
-  (require (lib "file.ss")(lib "match.ss"))
+  (require (lib "file.rkt") (lib "match.rkt"))
   (provide apply-to-scheme-files)
 
    (define-syntax (define-excluder stx)
@@ -27,8 +27,8 @@
 
   ;; ----------------------------------------
   ;; apply-to-scheme-files: (path[file] -> X) path[directory] -> (listof X)
-  ;; applies the given function to each .ss or .scm file in the given directory
-  ;; hierarchy; returns all results in a list
+  ;; applies the given function to each .rkt or .ss or .scm file in the given
+  ;; directory hierarchy; returns all results in a list
   (define  (apply-to-scheme-files f root )
      ;;FOLD-FILES
 
diff --git a/collects/tests/typed-scheme/succeed/leftist-heap.rkt b/collects/tests/typed-scheme/succeed/leftist-heap.rkt
index ef35166421..4d87e6c386 100644
--- a/collects/tests/typed-scheme/succeed/leftist-heap.rkt
+++ b/collects/tests/typed-scheme/succeed/leftist-heap.rkt
@@ -23,8 +23,8 @@
 ;; need rest args
 ;; didn't attempt generators
 
-;#reader (planet "typed-reader.ss" ("plt" "typed-scheme.plt"))
-;(module leftist-heap (planet "typed-scheme.ss" ("plt" "typed-scheme.plt" 3 0))
+;#reader (planet "typed-reader.rkt" ("plt" "typed-scheme.plt"))
+;(module leftist-heap (planet "typed-scheme.rkt" ("plt" "typed-scheme.plt" 3 0))
 ;(module leftist-heap mzscheme
 
 #lang typed-scheme
@@ -35,7 +35,7 @@
 (define-type-alias list-of Listof)
 (require
    (except-in srfi/67 current-compare =? <?)
-   #;"typed-list.ss"
+   #;"typed-list.rkt"
    #;srfi/42
    #;(only mzlib/list foldl))
 
diff --git a/collects/tests/typed-scheme/succeed/little-schemer.rkt b/collects/tests/typed-scheme/succeed/little-schemer.rkt
index a0cb66769e..a32d491941 100644
--- a/collects/tests/typed-scheme/succeed/little-schemer.rkt
+++ b/collects/tests/typed-scheme/succeed/little-schemer.rkt
@@ -1,6 +1,6 @@
 #lang typed-scheme
 #;(require mzlib/etc)
-#;(require "prims.ss")
+#;(require "prims.rkt")
 (require mzlib/match
          (for-syntax scheme/base))
 
diff --git a/collects/tests/typed-scheme/succeed/match-expander-problem.rkt b/collects/tests/typed-scheme/succeed/match-expander-problem.rkt
index dc6400e660..4adecb673d 100644
--- a/collects/tests/typed-scheme/succeed/match-expander-problem.rkt
+++ b/collects/tests/typed-scheme/succeed/match-expander-problem.rkt
@@ -1,7 +1,7 @@
 #lang typed-scheme
 
 #;(require mzlib/etc)
-;(require "prims.ss")
+;(require "prims.rkt")
 (require mzlib/match)
 
 (define-typed-struct pt ([x : Number] [y : Number]))
diff --git a/collects/tests/typed-scheme/succeed/metrics.rkt b/collects/tests/typed-scheme/succeed/metrics.rkt
index 4cd03a5b7a..7aafcd9406 100644
--- a/collects/tests/typed-scheme/succeed/metrics.rkt
+++ b/collects/tests/typed-scheme/succeed/metrics.rkt
@@ -2,7 +2,7 @@
 (provide results run-all-tests)
 
 #;(require "../list.scm"
-         "../etc.ss")
+         "../etc.rkt")
 (require/typed apply-to-scheme-files
                ((Path -> (Listof (Listof (U #f (Listof (U Real #f))))))
                 Path
@@ -11,18 +11,18 @@
 (define-type-alias top Any)
 (define-type-alias str String)
 
-(require/typed filename-extension (Path -> (U #f Bytes)) (lib "file.ss"))
-(require/typed normalize-path (Path Path -> Path) (lib "file.ss"))
-(require/typed explode-path (Path -> (Listof Path)) (lib "file.ss"))
-(require/typed srfi48::format (Port String String top * -> top)  "patch.ss")
+(require/typed filename-extension (Path -> (U #f Bytes)) (lib "file.rkt"))
+(require/typed normalize-path (Path Path -> Path) (lib "file.rkt"))
+(require/typed explode-path (Path -> (Listof Path)) (lib "file.rkt"))
+(require/typed srfi48::format (Port String String top * -> top)  "patch.rkt")
 ;; FIXME - prefix
-#;(require/typed srfi48:format ( Port String String top * -> top) (prefix-in srfi48: (lib "48.ss" "srfi")))
-(require (lib "match.ss")
-         ;(lib "file.ss")
-         ;(lib "list.ss")
-         ;(lib "etc.ss")
-         (prefix-in srfi13: (lib "13.ss" "srfi"))
-         ;(prefix srfi48: (lib "48.ss" "srfi"))
+#;(require/typed srfi48:format ( Port String String top * -> top) (prefix-in srfi48: (lib "48.rkt" "srfi")))
+(require (lib "match.rkt")
+         ;(lib "file.rkt")
+         ;(lib "list.rkt")
+         ;(lib "etc.rkt")
+         (prefix-in srfi13: (lib "13.rkt" "srfi"))
+         ;(prefix srfi48: (lib "48.rkt" "srfi"))
          )
 
 (define-type-alias Sexpr Any)
@@ -367,7 +367,7 @@
 ;; ============================================================
 ;; EXPERIMENT RUNNING
 
-;; FIXME - everything in untyped file (foldo.ss) b/c fold-files has terrible api
+;; FIXME - everything in untyped file (foldo.rkt) b/c fold-files has terrible api
 #;(define-syntax (define-excluder stx)
 
     (define (path->clause c)
@@ -393,8 +393,8 @@
 
 ;; ----------------------------------------
 ;; apply-to-scheme-files: (path[file] -> X) path[directory] -> (listof X)
-;; applies the given function to each .ss or .scm file in the given directory
-;; hierarchy; returns all results in a list
+;; applies the given function to each .rkt or .ss or .scm file in the given
+;; directory hierarchy; returns all results in a list
 #;(define:  (apply-to-scheme-files [f : (Path -> (Listof(Listof(Listof NumF))))]
                                    [root : Path])
     : (Listof (Listof(Listof(Listof NumF)))) ;;FOLD-FILES
diff --git a/collects/tests/typed-scheme/succeed/new-metrics.rkt b/collects/tests/typed-scheme/succeed/new-metrics.rkt
index a812d0c4af..da284ac88e 100644
--- a/collects/tests/typed-scheme/succeed/new-metrics.rkt
+++ b/collects/tests/typed-scheme/succeed/new-metrics.rkt
@@ -343,8 +343,8 @@
 
 ;; ----------------------------------------
 ;; apply-to-scheme-files: (path[file] -> X) path[directory] -> (listof X)
-;; applies the given function to each .ss or .scm file in the given directory
-;; hierarchy; returns all results in a list
+;; applies the given function to each .rkt or .ss or .scm file in the given
+;; directory hierarchy; returns all results in a list
 (: apply-to-scheme-files (All (X) ((Path -> X) Path -> (Listof X))))
 (define  (apply-to-scheme-files f root)
   (fold-files
diff --git a/collects/tests/typed-scheme/succeed/poly-tests.rkt b/collects/tests/typed-scheme/succeed/poly-tests.rkt
index 163cd36674..6458bf98e3 100644
--- a/collects/tests/typed-scheme/succeed/poly-tests.rkt
+++ b/collects/tests/typed-scheme/succeed/poly-tests.rkt
@@ -4,7 +4,7 @@
 (define-type-alias symbol Symbol)
 (define-type-alias top Any)
 (define-type-alias list-of Listof)
-#;(require "prims.ss")
+#;(require "prims.rkt")
 (define: mymap : (All (a b) ((a -> b) (list-of a) -> (list-of b)))
   (plambda: (a b) ([f : (a -> b)] [l : (list-of a)])
 	    (cond [(null? l) '()]
diff --git a/collects/tests/typed-scheme/succeed/require-poly.rkt b/collects/tests/typed-scheme/succeed/require-poly.rkt
index 68f90fc92c..28b6ef2e36 100644
--- a/collects/tests/typed-scheme/succeed/require-poly.rkt
+++ b/collects/tests/typed-scheme/succeed/require-poly.rkt
@@ -1,3 +1,3 @@
 #lang typed-scheme
 
-(require "simple-poly.ss")
+(require "simple-poly.rkt")
diff --git a/collects/tests/typed-scheme/succeed/seasoned-schemer.rkt b/collects/tests/typed-scheme/succeed/seasoned-schemer.rkt
index bae63bb505..3aa746f344 100644
--- a/collects/tests/typed-scheme/succeed/seasoned-schemer.rkt
+++ b/collects/tests/typed-scheme/succeed/seasoned-schemer.rkt
@@ -1,6 +1,6 @@
 #lang typed-scheme
 #;(require mzlib/etc)
-#;(require "prims.ss")
+#;(require "prims.rkt")
 (require mzlib/match)
 
 (define-type-alias number Number)
diff --git a/collects/tests/typed-scheme/unit-tests/all-tests.rkt b/collects/tests/typed-scheme/unit-tests/all-tests.rkt
index 53e17b4f83..19ed558ab5 100644
--- a/collects/tests/typed-scheme/unit-tests/all-tests.rkt
+++ b/collects/tests/typed-scheme/unit-tests/all-tests.rkt
@@ -1,19 +1,19 @@
 #lang scheme/base
 
 (require
- "test-utils.ss"
- "typecheck-tests.ss" ;;fail
+ "test-utils.rkt"
+ "typecheck-tests.rkt" ;;fail
 
- "subtype-tests.ss" ;; pass
- "type-equal-tests.ss" ;; pass
- "remove-intersect-tests.ss" ;; pass
- "parse-type-tests.ss" ;; pass
- "subst-tests.ss" ;; pass
- "infer-tests.ss" ;; pass
- "type-annotation-test.ss" ;; pass
+ "subtype-tests.rkt" ;; pass
+ "type-equal-tests.rkt" ;; pass
+ "remove-intersect-tests.rkt" ;; pass
+ "parse-type-tests.rkt" ;; pass
+ "subst-tests.rkt" ;; pass
+ "infer-tests.rkt" ;; pass
+ "type-annotation-test.rkt" ;; pass
 
- "module-tests.ss" ;; pass
- "contract-tests.ss"
+ "module-tests.rkt" ;; pass
+ "contract-tests.rkt"
 
  (r:infer infer infer-dummy)
  rackunit rackunit/text-ui)
diff --git a/collects/tests/typed-scheme/unit-tests/contract-tests.rkt b/collects/tests/typed-scheme/unit-tests/contract-tests.rkt
index c11c80dfab..8272dea4f9 100644
--- a/collects/tests/typed-scheme/unit-tests/contract-tests.rkt
+++ b/collects/tests/typed-scheme/unit-tests/contract-tests.rkt
@@ -1,10 +1,10 @@
 #lang scheme/base
 
-(require "test-utils.ss"
+(require "test-utils.rkt"
          (for-syntax scheme/base)
          (for-template scheme/base)
          (private type-contract)
-	 (rep type-rep filter-rep object-rep)
+         (rep type-rep filter-rep object-rep)
          (types utils union convenience)
          (utils tc-utils)
          rackunit)
diff --git a/collects/tests/typed-scheme/unit-tests/infer-tests.rkt b/collects/tests/typed-scheme/unit-tests/infer-tests.rkt
index 9f34e83246..f37b2aee3f 100644
--- a/collects/tests/typed-scheme/unit-tests/infer-tests.rkt
+++ b/collects/tests/typed-scheme/unit-tests/infer-tests.rkt
@@ -1,8 +1,8 @@
 #lang scheme/base
-(require "test-utils.ss" (for-syntax scheme/base))
+(require "test-utils.rkt" (for-syntax scheme/base))
 (require (rep type-rep)
-	 (r:infer infer)
-	 (types convenience union utils abbrev)
+         (r:infer infer)
+         (types convenience union utils abbrev)
          rackunit)
 
 
diff --git a/collects/tests/typed-scheme/unit-tests/module-tests.rkt b/collects/tests/typed-scheme/unit-tests/module-tests.rkt
index 2292f2f8c8..68121ee01c 100644
--- a/collects/tests/typed-scheme/unit-tests/module-tests.rkt
+++ b/collects/tests/typed-scheme/unit-tests/module-tests.rkt
@@ -1,11 +1,11 @@
 #lang scheme
-(require "test-utils.ss" rackunit)
+(require "test-utils.rkt" rackunit)
 
 (provide module-tests)
 
 (define (module-tests)
   (test-suite "Tests for whole modules"
-              #;(test-not-exn "name" (lambda () (expand #'(module m (planet "typed-scheme.ss" ("plt" "typed-scheme.plt"))
+              #;(test-not-exn "name" (lambda () (expand #'(module m (planet "typed-scheme.rkt" ("plt" "typed-scheme.plt"))
                                                             (define: x : number 3)))))
               ))
 
diff --git a/collects/tests/typed-scheme/unit-tests/parse-type-tests.rkt b/collects/tests/typed-scheme/unit-tests/parse-type-tests.rkt
index 9bdcecbe97..7c345193bb 100644
--- a/collects/tests/typed-scheme/unit-tests/parse-type-tests.rkt
+++ b/collects/tests/typed-scheme/unit-tests/parse-type-tests.rkt
@@ -1,10 +1,10 @@
 #lang scheme/base
-(require "test-utils.ss" (for-syntax scheme/base)
+(require "test-utils.rkt" (for-syntax scheme/base)
          racket/set
          (utils tc-utils)
-	 (env type-alias-env type-env-structs tvar-env type-name-env init-envs)
-	 (rep type-rep)
-	 (rename-in (types comparison subtype union utils convenience)
+         (env type-alias-env type-env-structs tvar-env type-name-env init-envs)
+         (rep type-rep)
+         (rename-in (types comparison subtype union utils convenience)
                     [Un t:Un] [-> t:->] [->* t:->*])
          (base-env base-types base-types-extra colon)
          (for-template (base-env base-types base-types-extra base-env colon))
@@ -15,7 +15,7 @@
 
 ;; HORRIBLE HACK!
 ;; We are solving the following problem:
-;; when we require "base-env.ss" for template, it constructs the type-alias-env
+;; when we require "base-env.rkt" for template, it constructs the type-alias-env
 ;; in phase 0 (relative to this module), but populates it with phase -1 identifiers
 ;; The identifiers are also bound in this module at phase -1, but the comparison for
 ;; the table is phase 0, so they don't compare correctly
@@ -24,7 +24,7 @@
 ;; We do this by going through the table, constructing new identifiers based on the symbol
 ;; of the old identifier.
 ;; This relies on the identifiers being bound at phase 0 in this module (which they are,
-;; because we have a phase 0 require of "base-env.ss").
+;; because we have a phase 0 require of "base-env.rkt").
 (for ([pr (type-alias-env-map cons)])
   (let ([nm (car pr)]
         [ty (cdr pr)])
diff --git a/collects/tests/typed-scheme/unit-tests/planet-requires.rkt b/collects/tests/typed-scheme/unit-tests/planet-requires.rkt
index 377fac186e..9d27c6a3d1 100644
--- a/collects/tests/typed-scheme/unit-tests/planet-requires.rkt
+++ b/collects/tests/typed-scheme/unit-tests/planet-requires.rkt
@@ -36,12 +36,12 @@
 
 (define-module rackunit
   (planet/multiple ("schematics" "rackunit.plt" 2 11)
-                   "test.ss"
-                   ;"graphical-ui.ss"
-                   "text-ui.ss"
-                   "util.ss")
+                   "test.rkt"
+                   ;"graphical-ui.rkt"
+                   "text-ui.rkt"
+                   "util.rkt")
   ;; disabled until Carl updates to v4
   #;
   (planet/multiple ("cce" "fasttest.plt" 1 2)
-                   "random.ss"
-                   "rackunit.ss"))
+                   "random.rkt"
+                   "rackunit.rkt"))
diff --git a/collects/tests/typed-scheme/unit-tests/remove-intersect-tests.rkt b/collects/tests/typed-scheme/unit-tests/remove-intersect-tests.rkt
index 489e941d91..f13e8a6d4c 100644
--- a/collects/tests/typed-scheme/unit-tests/remove-intersect-tests.rkt
+++ b/collects/tests/typed-scheme/unit-tests/remove-intersect-tests.rkt
@@ -1,7 +1,7 @@
 #lang scheme/base
-(require "test-utils.ss" (for-syntax scheme/base)
+(require "test-utils.rkt" (for-syntax scheme/base)
          (rep type-rep)
-	 (r:infer infer infer-dummy)
+         (r:infer infer infer-dummy)
          (types convenience subtype union remove-intersect)
          rackunit)
 
diff --git a/collects/tests/typed-scheme/unit-tests/subst-tests.rkt b/collects/tests/typed-scheme/unit-tests/subst-tests.rkt
index 5a5efe2d4f..3cb49a4137 100644
--- a/collects/tests/typed-scheme/unit-tests/subst-tests.rkt
+++ b/collects/tests/typed-scheme/unit-tests/subst-tests.rkt
@@ -1,8 +1,8 @@
 #lang scheme/base
 
-(require "test-utils.ss" (for-syntax scheme/base)
+(require "test-utils.rkt" (for-syntax scheme/base)
          (rep type-rep)
-	 (types utils abbrev numeric-tower substitute)
+         (types utils abbrev numeric-tower substitute)
          rackunit)
 
 (define-syntax-rule (s img var tgt result)
diff --git a/collects/tests/typed-scheme/unit-tests/subtype-tests.rkt b/collects/tests/typed-scheme/unit-tests/subtype-tests.rkt
index a69e68cab1..898db32a87 100644
--- a/collects/tests/typed-scheme/unit-tests/subtype-tests.rkt
+++ b/collects/tests/typed-scheme/unit-tests/subtype-tests.rkt
@@ -1,10 +1,10 @@
 #lang scheme/base
 
-(require "test-utils.ss"
+(require "test-utils.rkt"
          (types subtype convenience union)
-	 (rep type-rep)
-	 (env init-envs type-env-structs)
-	 (r:infer infer infer-dummy)
+         (rep type-rep)
+         (env init-envs type-env-structs)
+         (r:infer infer infer-dummy)
          rackunit
          (for-syntax scheme/base))
 
diff --git a/collects/tests/typed-scheme/unit-tests/type-annotation-test.rkt b/collects/tests/typed-scheme/unit-tests/type-annotation-test.rkt
index 82954507e6..6a4f73446f 100644
--- a/collects/tests/typed-scheme/unit-tests/type-annotation-test.rkt
+++ b/collects/tests/typed-scheme/unit-tests/type-annotation-test.rkt
@@ -1,12 +1,12 @@
 #lang scheme/base
-(require "test-utils.ss"
+(require "test-utils.rkt"
          (for-syntax scheme/base)
          typed-scheme/private/type-annotation
          typed-scheme/private/parse-type
          (types abbrev numeric-tower utils)
-	 (env type-env-structs init-envs)
-	 (utils tc-utils)
-	 (rep type-rep filter-rep object-rep)
+         (env type-env-structs init-envs)
+         (utils tc-utils)
+         (rep type-rep filter-rep object-rep)
          rackunit)
 
 (provide type-annotation-tests)
diff --git a/collects/tests/typed-scheme/unit-tests/type-equal-tests.rkt b/collects/tests/typed-scheme/unit-tests/type-equal-tests.rkt
index e183117e4f..c57bf72771 100644
--- a/collects/tests/typed-scheme/unit-tests/type-equal-tests.rkt
+++ b/collects/tests/typed-scheme/unit-tests/type-equal-tests.rkt
@@ -1,8 +1,8 @@
 #lang scheme/base
 
-(require "test-utils.ss" (for-syntax scheme/base)
+(require "test-utils.rkt" (for-syntax scheme/base)
          (rep type-rep)
-	 (types comparison abbrev numeric-tower union)
+         (types comparison abbrev numeric-tower union)
          rackunit)
 
 (provide type-equal-tests)
diff --git a/collects/tests/typed-scheme/unit-tests/typecheck-tests.rkt b/collects/tests/typed-scheme/unit-tests/typecheck-tests.rkt
index 1ef3656e72..ef38611582 100644
--- a/collects/tests/typed-scheme/unit-tests/typecheck-tests.rkt
+++ b/collects/tests/typed-scheme/unit-tests/typecheck-tests.rkt
@@ -1,14 +1,14 @@
 #lang racket/base
 
-(require "test-utils.ss"
+(require "test-utils.rkt"
          (for-syntax scheme/base)
          (for-template scheme/base))
 (require (private type-annotation parse-type)
          (base-env prims
                    base-types-extra base-special-env
                    base-env-indexing base-structs)
-	 (typecheck typechecker)
-	 (rep type-rep filter-rep object-rep)
+         (typecheck typechecker)
+         (rep type-rep filter-rep object-rep)
          (rename-in (types utils union convenience abbrev filter-ops)
                     [Un t:Un]
                     [true-lfilter -true-lfilter]
diff --git a/collects/tests/unstable/contract.rkt b/collects/tests/unstable/contract.rkt
index 32254042af..ed86edc83b 100644
--- a/collects/tests/unstable/contract.rkt
+++ b/collects/tests/unstable/contract.rkt
@@ -3,7 +3,7 @@
 (require rackunit rackunit/text-ui unstable/contract "helpers.rkt")
 
 (run-tests
- (test-suite "contract.ss"
+ (test-suite "contract.rkt"
    (test-suite "Flat Contracts"
      (test-suite "nat/c"
        (test-ok (with/c nat/c 1))
diff --git a/collects/tests/unstable/debug.rkt b/collects/tests/unstable/debug.rkt
index 0482b2c2cf..0bbc6758a8 100644
--- a/collects/tests/unstable/debug.rkt
+++ b/collects/tests/unstable/debug.rkt
@@ -3,7 +3,7 @@
 (require rackunit rackunit/text-ui unstable/debug "helpers.rkt")
 
 (run-tests
- (test-suite "debug.ss"
+ (test-suite "debug.rkt"
    (test-suite "dprintf"
      (test
       (let ()
diff --git a/collects/tests/unstable/define.rkt b/collects/tests/unstable/define.rkt
index ec393de503..dbd7dcceb7 100644
--- a/collects/tests/unstable/define.rkt
+++ b/collects/tests/unstable/define.rkt
@@ -3,7 +3,7 @@
 (require rackunit rackunit/text-ui racket/sandbox unstable/define "helpers.rkt")
 
 (run-tests
- (test-suite "define.ss"
+ (test-suite "define.rkt"
 
    (test-suite "at-end")
 
diff --git a/collects/tests/unstable/dict.rkt b/collects/tests/unstable/dict.rkt
index 632b01990d..8211d0291e 100644
--- a/collects/tests/unstable/dict.rkt
+++ b/collects/tests/unstable/dict.rkt
@@ -14,7 +14,7 @@
 (define (check/dict a b) (check dict=? a b))
 
 (run-tests
- (test-suite "dict.ss"
+ (test-suite "dict.rkt"
    (test-suite "Accessors"
      (test-suite "dict-empty?"
        (test (check-true (dict-empty? '())))
diff --git a/collects/tests/unstable/exn.rkt b/collects/tests/unstable/exn.rkt
index b774d7ba86..63e86c127d 100644
--- a/collects/tests/unstable/exn.rkt
+++ b/collects/tests/unstable/exn.rkt
@@ -3,7 +3,7 @@
 (require rackunit rackunit/text-ui unstable/exn "helpers.rkt")
 
 (run-tests
- (test-suite "exn.ss"
+ (test-suite "exn.rkt"
    (test-suite "try"
      (test-ok (try (+ 1 2)))
      (test-bad (try (+ 'a 'b)))
diff --git a/collects/tests/unstable/function.rkt b/collects/tests/unstable/function.rkt
index fc6efda0ee..5f3045e280 100644
--- a/collects/tests/unstable/function.rkt
+++ b/collects/tests/unstable/function.rkt
@@ -5,7 +5,7 @@
 (define list/kw (make-keyword-procedure list))
 
 (run-tests
- (test-suite "function.ss"
+ (test-suite "function.rkt"
 
    (test-suite "Simple Functions"
 
diff --git a/collects/tests/unstable/hash.rkt b/collects/tests/unstable/hash.rkt
index 95f2458b69..6cd69891e8 100644
--- a/collects/tests/unstable/hash.rkt
+++ b/collects/tests/unstable/hash.rkt
@@ -3,7 +3,7 @@
 (require rackunit rackunit/text-ui unstable/hash "helpers.rkt")
 
 (run-tests
- (test-suite "hash.ss"
+ (test-suite "hash.rkt"
    (test-suite "hash-union"
      (test-ok (hash-union #hash([1 . one] [2 . two])
                           #hash([3 . three] [4 . four]))
diff --git a/collects/tests/unstable/match.rkt b/collects/tests/unstable/match.rkt
index a356b1daa1..4a4b55d780 100644
--- a/collects/tests/unstable/match.rkt
+++ b/collects/tests/unstable/match.rkt
@@ -3,7 +3,7 @@
 (require unstable/match rackunit rackunit/text-ui "helpers.rkt")
 
 (run-tests
- (test-suite "match.ss"
+ (test-suite "match.rkt"
    (test-suite "match?"
      (test
       (check-true (match? (list 1 2 3)
diff --git a/collects/tests/unstable/planet-syntax.rkt b/collects/tests/unstable/planet-syntax.rkt
index 46090bdf3c..b43e8fefe1 100644
--- a/collects/tests/unstable/planet-syntax.rkt
+++ b/collects/tests/unstable/planet-syntax.rkt
@@ -15,7 +15,7 @@
          1 1 1 1)))
 
 (run-tests
- (test-suite "planet-syntax.ss"
+ (test-suite "planet-syntax.rkt"
 
    (test-suite "syntax-source-planet-package"
      (test-case "fail"
diff --git a/collects/tests/unstable/port.rkt b/collects/tests/unstable/port.rkt
index 5d80f5ac32..c0acbff1d2 100644
--- a/collects/tests/unstable/port.rkt
+++ b/collects/tests/unstable/port.rkt
@@ -3,7 +3,7 @@
 (require rackunit rackunit/text-ui unstable/port "helpers.rkt")
 
 (run-tests
- (test-suite "port.ss"
+ (test-suite "port.rkt"
    (test-suite "read-all"
      (test-ok (check-equal? (read-all read (open-input-string "1 2 3"))
                             (list 1 2 3)))
diff --git a/collects/tests/unstable/set.rkt b/collects/tests/unstable/set.rkt
index d245c8f4bd..b20bd13676 100644
--- a/collects/tests/unstable/set.rkt
+++ b/collects/tests/unstable/set.rkt
@@ -9,7 +9,7 @@
   (test (check/set arg ...)))
 
 (run-tests
- (test-suite "set.ss"
+ (test-suite "set.rkt"
    (test-suite "Conversions"
      (test-suite "list->set"
        (test/set (list->set (list 'a 'b 'c)) (list 'a 'b 'c))
diff --git a/collects/tests/unstable/syntax.rkt b/collects/tests/unstable/syntax.rkt
index 2c4974906f..242a87382f 100644
--- a/collects/tests/unstable/syntax.rkt
+++ b/collects/tests/unstable/syntax.rkt
@@ -15,7 +15,7 @@
          1 1 1 1)))
 
 (run-tests
- (test-suite "syntax.ss"
+ (test-suite "syntax.rkt"
 
    (test-suite "Syntax Lists"
 
diff --git a/collects/tests/utils/mz-testing.rkt b/collects/tests/utils/mz-testing.rkt
index 4376b9e971..df6bfad5a4 100644
--- a/collects/tests/utils/mz-testing.rkt
+++ b/collects/tests/utils/mz-testing.rkt
@@ -32,7 +32,7 @@
 	   exn:application:type?
 	   exn:application:arity?)
   
-  ; The format of the next line is important: file.ss relies on it
+  ; The format of the next line is important: file.rkt relies on it
   ; JBC : not in this version...
   (define cur-section '())(define errs '())
   
@@ -170,7 +170,7 @@
         (thunk-error-test (lambda () (eval expr)) expr exn?)])))
   
   ; JBC : I'm not going to worry about this for the time being :
-  ; (require (rename mzscheme err:mz:lambda lambda)) ; so err/rt-test works with beginner.ss
+  ; (require (rename mzscheme err:mz:lambda lambda)) ; so err/rt-test works with beginner.rkt
 
   (define-syntax err/rt-test
     (lambda (stx)
diff --git a/collects/tests/web-server/http/digest-auth-test.rkt b/collects/tests/web-server/http/digest-auth-test.rkt
index 321b755d4a..061c8af553 100644
--- a/collects/tests/web-server/http/digest-auth-test.rkt
+++ b/collects/tests/web-server/http/digest-auth-test.rkt
@@ -29,12 +29,12 @@ END
     [opaque . "5ccc069c403ebaf9f0171e9517f40e41"]))
 
 (define Safari-Example-bytes
-  #"Digest username=\"username\", realm=\"Digest Auth Test: g10971\", nonce=\"MTIzMzc2ODU3NCA4MjA2MTAyMDNhYzYyYTRiMTdmOTY4NzVjOWI1MzEwOQ==\", uri=\"/servlets/standalone.ss\", response=\"c3e45e8499e37bf0872930b35fcae291\", cnonce=\"94db38ffd6e360db658e0dbcbf5e43b9\", nc=00000001, qop=\"auth\"")
+  #"Digest username=\"username\", realm=\"Digest Auth Test: g10971\", nonce=\"MTIzMzc2ODU3NCA4MjA2MTAyMDNhYzYyYTRiMTdmOTY4NzVjOWI1MzEwOQ==\", uri=\"/servlets/standalone.rkt\", response=\"c3e45e8499e37bf0872930b35fcae291\", cnonce=\"94db38ffd6e360db658e0dbcbf5e43b9\", nc=00000001, qop=\"auth\"")
 (define Safari-Example-alist
   '([username . "username"]
     [realm . "Digest Auth Test: g10971"]
     [nonce . "MTIzMzc2ODU3NCA4MjA2MTAyMDNhYzYyYTRiMTdmOTY4NzVjOWI1MzEwOQ=="]
-    [uri . "/servlets/standalone.ss"]
+    [uri . "/servlets/standalone.rkt"]
     [response . "c3e45e8499e37bf0872930b35fcae291"]
     [cnonce . "94db38ffd6e360db658e0dbcbf5e43b9"]
     [nc . "00000001"]
diff --git a/collects/tex2page/info.rkt b/collects/tex2page/info.rkt
index f6f25515bc..89ad582935 100644
--- a/collects/tex2page/info.rkt
+++ b/collects/tex2page/info.rkt
@@ -1,4 +1,4 @@
 #lang setup/infotab
 
-(define mzscheme-launcher-libraries (list "start.ss"))
+(define mzscheme-launcher-libraries (list "start.rkt"))
 (define mzscheme-launcher-names (list "tex2page"))
diff --git a/collects/tex2page/main.rkt b/collects/tex2page/main.rkt
index 16f04ddbcc..1b6a321d6b 100644
--- a/collects/tex2page/main.rkt
+++ b/collects/tex2page/main.rkt
@@ -1,4 +1,4 @@
 #lang scheme/base
 
-(require "tex2page.ss")
-(provide (all-from-out "tex2page.ss"))
+(require "tex2page.rkt")
+(provide (all-from-out "tex2page.rkt"))
diff --git a/collects/tex2page/start.rkt b/collects/tex2page/start.rkt
index ec897c5767..2419ae88e1 100644
--- a/collects/tex2page/start.rkt
+++ b/collects/tex2page/start.rkt
@@ -1,6 +1,6 @@
 (module start mzscheme
-  (require "tex2page.ss"
-	   mzlib/cmdline)
+  (require "tex2page.rkt"
+           mzlib/cmdline)
 
   (command-line
    "tex2page"
@@ -9,4 +9,4 @@
     [("--version") "Reports long help and version information"
      (tex2page "--version")]]
    [args file "Processes each <file>"
-	 (map tex2page file)]))
+         (map tex2page file)]))
diff --git a/collects/tex2page/tex2page.rkt b/collects/tex2page/tex2page.rkt
index f17051a792..3a98209af1 100644
--- a/collects/tex2page/tex2page.rkt
+++ b/collects/tex2page/tex2page.rkt
@@ -8,5 +8,5 @@
        ((current-namespace (make-namespace)))
        (namespace-require
         `(file ,(path->string (build-path (this-expression-source-directory)
-                                          "tex2page-aux.ss"))))
+                                          "tex2page-aux.rkt"))))
        ((namespace-variable-value 'tex2page) f)))))
diff --git a/collects/texpict/balloon.rkt b/collects/texpict/balloon.rkt
index efbd448328..6fd6ee13cb 100644
--- a/collects/texpict/balloon.rkt
+++ b/collects/texpict/balloon.rkt
@@ -1,22 +1,22 @@
 (module balloon mzscheme
-  (require "mrpict.ss"
-	   "utils.ss"
-	   racket/draw
+  (require "mrpict.rkt"
+           "utils.rkt"
+           racket/draw
            mzlib/class
            mzlib/etc
            mzlib/math)
-  
+
   (provide wrap-balloon pip-wrap-balloon
-	   place-balloon
-	   pin-balloon
-	   (rename mk-balloon balloon)
+           place-balloon
+           pin-balloon
+           (rename mk-balloon balloon)
            make-balloon
-	   balloon?
+           balloon?
            balloon-pict
            balloon-point-x
            balloon-point-y
-	   balloon-color)
-  
+           balloon-color)
+
   (define-struct balloon (pict point-x point-y))
     
   (define no-pen (find-pen "white" 1 'transparent))
diff --git a/collects/texpict/code.rkt b/collects/texpict/code.rkt
index 4ed03d469d..9c928e24f4 100644
--- a/collects/texpict/code.rkt
+++ b/collects/texpict/code.rkt
@@ -1,8 +1,8 @@
 (module code racket/base
-  (require "mrpict.ss"
-	   (prefix-in r: racket/base)
+  (require "mrpict.rkt"
+           (prefix-in r: racket/base)
            mzlib/class
-	   mzlib/list
+           mzlib/list
            (only-in scheme/list last)
            racket/draw
            mzlib/unit
diff --git a/collects/texpict/face-demo.rkt b/collects/texpict/face-demo.rkt
index e1e9adca1b..378496ce04 100644
--- a/collects/texpict/face-demo.rkt
+++ b/collects/texpict/face-demo.rkt
@@ -3,10 +3,10 @@
            mzlib/class
            texpict/utils
            texpict/mrpict
-           "face.ss")
-  
+           "face.rkt")
+
   (define f (new frame% (label "frame")))
-  
+
   (define canvas-scale 1)
   
   (define c (new canvas%
diff --git a/collects/texpict/flash.rkt b/collects/texpict/flash.rkt
index b58330f7b6..a498cc7f99 100644
--- a/collects/texpict/flash.rkt
+++ b/collects/texpict/flash.rkt
@@ -1,13 +1,12 @@
-
 (module flash mzscheme
-  (require "mrpict.ss"
-	   mzlib/math
-	   mzlib/etc
+  (require "mrpict.rkt"
+           mzlib/math
+           mzlib/etc
            racket/draw
            mzlib/class)
 
   (provide filled-flash
-	   outline-flash)
+           outline-flash)
 
   (define-syntax define-flash
     (syntax-rules ()
diff --git a/collects/texpict/mrpict-sig.rkt b/collects/texpict/mrpict-sig.rkt
index 8684d95074..af8a72d3ef 100644
--- a/collects/texpict/mrpict-sig.rkt
+++ b/collects/texpict/mrpict-sig.rkt
@@ -1,10 +1,8 @@
-
 (module mrpict-sig mzscheme
   (require mzlib/unit)
-  
-  (require "private/common-sig.ss")
-  (require "private/mrpict-sig.ss")
-  
+
+  (require "private/common-sig.rkt")
+  (require "private/mrpict-sig.rkt")
+
   (provide texpict-common^
            mrpict-extra^))
-
diff --git a/collects/texpict/mrpict-unit.rkt b/collects/texpict/mrpict-unit.rkt
index 135e832706..cef11b95a0 100644
--- a/collects/texpict/mrpict-unit.rkt
+++ b/collects/texpict/mrpict-unit.rkt
@@ -1,14 +1,13 @@
-
 (module mrpict-unit mzscheme
   (require mzlib/unit)
 
   (require racket/draw/draw-sig)
 
-  (require "private/mrpict-sig.ss"
-	   "private/common-sig.ss"
-	   "private/common-unit.ss"
-	   "private/mrpict-extra.ss")
-	
+  (require "private/mrpict-sig.rkt"
+           "private/common-sig.rkt"
+           "private/common-unit.rkt"
+           "private/mrpict-extra.rkt")
+
   (provide mrpict@)
   (define-compound-unit/infer mrpict@
     (import draw^)
diff --git a/collects/texpict/mrpict.rkt b/collects/texpict/mrpict.rkt
index e39bcd73b1..96619edb16 100644
--- a/collects/texpict/mrpict.rkt
+++ b/collects/texpict/mrpict.rkt
@@ -6,11 +6,11 @@
            racket/draw)
 
   (require racket/draw/draw-sig
-	   racket/draw/draw-unit)
-  (require "private/mrpict-sig.ss"
-	   "private/common-sig.ss")
-  (require "mrpict-sig.ss"
-	   "mrpict-unit.ss")
+           racket/draw/draw-unit
+           "private/mrpict-sig.rkt"
+           "private/common-sig.rkt"
+           "mrpict-sig.rkt"
+           "mrpict-unit.rkt")
 
   (define-compound-unit/infer mrpict+mred@
     (import)
diff --git a/collects/texpict/private/common-unit.rkt b/collects/texpict/private/common-unit.rkt
index 66afc4c0ff..3ac3945982 100644
--- a/collects/texpict/private/common-unit.rkt
+++ b/collects/texpict/private/common-unit.rkt
@@ -4,8 +4,8 @@
            racket/class
            racket/list
            file/convertible)
-  
-  (require "common-sig.ss")
+
+  (require "common-sig.rkt")
 
   (import texpict-common-setup^)
   (export texpict-common^ texpict-internal^)
diff --git a/collects/texpict/private/mrpict-extra.rkt b/collects/texpict/private/mrpict-extra.rkt
index 10ba5f1b6d..a65e14d9f2 100644
--- a/collects/texpict/private/mrpict-extra.rkt
+++ b/collects/texpict/private/mrpict-extra.rkt
@@ -1,4 +1,3 @@
-
 #lang scheme/unit
 
   (require mzlib/class
@@ -7,8 +6,8 @@
   (require racket/draw/draw-sig
            racket/gui/dynamic)
 
-  (require "mrpict-sig.ss"
-	   "common-sig.ss")
+  (require "mrpict-sig.rkt"
+           "common-sig.rkt")
 
   (import draw^
           texpict-common^
diff --git a/collects/texpict/private/texpict-extra.rkt b/collects/texpict/private/texpict-extra.rkt
index 1697f89853..1ddb20ef23 100644
--- a/collects/texpict/private/texpict-extra.rkt
+++ b/collects/texpict/private/texpict-extra.rkt
@@ -1,11 +1,10 @@
-
 #lang scheme/unit
 
   (require mzlib/etc
-	   mzlib/list)
+           mzlib/list)
 
-  (require "texpict-sig.ss"
-	   "common-sig.ss")
+  (require "texpict-sig.rkt"
+           "common-sig.rkt")
 
   (import texpict-common^
           texpict-internal^)
diff --git a/collects/texpict/slideshow-run.rkt b/collects/texpict/slideshow-run.rkt
index 8e8acb0edd..c88de6e1e5 100644
--- a/collects/texpict/slideshow-run.rkt
+++ b/collects/texpict/slideshow-run.rkt
@@ -1,6 +1,5 @@
-
-(module slideshow-run "slideshow.ss"
+(module slideshow-run "slideshow.rkt"
   (require (prefix slideshow: slideshow/run))
 
-  (provide (all-from-except "slideshow.ss" #%module-begin)
+  (provide (all-from-except "slideshow.rkt" #%module-begin)
            (rename slideshow:#%module-begin #%module-begin)))
diff --git a/collects/texpict/texpict-sig.rkt b/collects/texpict/texpict-sig.rkt
index 4b25386521..8666f934ff 100644
--- a/collects/texpict/texpict-sig.rkt
+++ b/collects/texpict/texpict-sig.rkt
@@ -1,10 +1,8 @@
-
 (module texpict-sig mzscheme
   (require mzlib/unit)
-  
-  (require "private/common-sig.ss")
-  (require "private/texpict-sig.ss")
-  
+
+  (require "private/common-sig.rkt")
+  (require "private/texpict-sig.rkt")
+
   (provide texpict-common^
            texpict-extra^))
-
diff --git a/collects/texpict/texpict-unit.rkt b/collects/texpict/texpict-unit.rkt
index 72e6f670f5..adaab63066 100644
--- a/collects/texpict/texpict-unit.rkt
+++ b/collects/texpict/texpict-unit.rkt
@@ -1,16 +1,14 @@
-
 (module texpict-unit mzscheme
   (require mzlib/unit)
 
-  (require "private/texpict-sig.ss"
-	   "private/common-sig.ss"
-	   "private/common-unit.ss"
-	   "private/texpict-extra.ss")
-	
+  (require "private/texpict-sig.rkt"
+           "private/common-sig.rkt"
+           "private/common-unit.rkt"
+           "private/texpict-extra.rkt")
+
   (provide texpict@)
   (define-compound-unit/infer texpict@
     (import)
     (export texpict-common^
             texpict-extra^)
     (link common@ texpict-extra@)))
-
diff --git a/collects/texpict/texpict.rkt b/collects/texpict/texpict.rkt
index 24a5827985..eb42b7bab2 100644
--- a/collects/texpict/texpict.rkt
+++ b/collects/texpict/texpict.rkt
@@ -1,13 +1,11 @@
-
 (module texpict mzscheme
   (require mzlib/unit)
 
-  (require "texpict-sig.ss"
-	   "texpict-unit.ss")
-  (require "private/texpict-sig.ss"
-	   "private/common-sig.ss")
+  (require "texpict-sig.rkt"
+           "texpict-unit.rkt"
+           "private/texpict-sig.rkt"
+           "private/common-sig.rkt")
   (define-values/invoke-unit/infer texpict@)
 
   (provide-signature-elements texpict-common^
                               texpict-extra^))
-
diff --git a/collects/texpict/utils.rkt b/collects/texpict/utils.rkt
index 4fedf0d5f9..514443733c 100644
--- a/collects/texpict/utils.rkt
+++ b/collects/texpict/utils.rkt
@@ -5,7 +5,7 @@
            racket/draw
            racket/math
            racket/gui/dynamic
-           "mrpict.ss")
+           "mrpict.rkt")
 
   ;; Utilities for use with mrpict
   
diff --git a/collects/trace/calltrace-lib.rkt b/collects/trace/calltrace-lib.rkt
index c3299b8c30..e7e0ef7fa6 100644
--- a/collects/trace/calltrace-lib.rkt
+++ b/collects/trace/calltrace-lib.rkt
@@ -1,15 +1,13 @@
-
 ;; Poor man's stack-trace-on-exceptions/profiler.
 ;; See docs for information.
 
 (module calltrace-lib mzscheme
-  (require "stacktrace.ss"
-           mzlib/list 
+  (require "stacktrace.rkt"
+           mzlib/list
            mzlib/etc
            mzlib/unit)
 
 
-  
   ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;; Eval handler, exception handler
 
@@ -74,4 +72,3 @@
   (provide calltrace-eval-handler
            instrumenting-enabled
            annotate))
- 
diff --git a/collects/trace/calltrace.rkt b/collects/trace/calltrace.rkt
index cd3f6ea655..f731eded25 100644
--- a/collects/trace/calltrace.rkt
+++ b/collects/trace/calltrace.rkt
@@ -1,9 +1,6 @@
-
 ;; Poor man's call tracer.
 
 (module calltrace mzscheme
-  (require "calltrace-lib.ss")
-  
+  (require "calltrace-lib.rkt")
   (provide instrumenting-enabled)
-  
   (current-eval calltrace-eval-handler))
diff --git a/collects/trace/main.rkt b/collects/trace/main.rkt
index a74f886734..f61df1e298 100644
--- a/collects/trace/main.rkt
+++ b/collects/trace/main.rkt
@@ -1,4 +1,4 @@
 #lang scheme/base
 
-(require "calltrace.ss")
-(provide (all-from-out "calltrace.ss"))
+(require "calltrace.rkt")
+(provide (all-from-out "calltrace.rkt"))
diff --git a/collects/typed-scheme/private/parse-type.rkt b/collects/typed-scheme/private/parse-type.rkt
index 40c8dc7a4e..be2f4d1b1a 100644
--- a/collects/typed-scheme/private/parse-type.rkt
+++ b/collects/typed-scheme/private/parse-type.rkt
@@ -8,10 +8,10 @@
          syntax/parse
          (env type-env-structs tvar-env type-name-env type-alias-env lexical-env index-env)
          racket/match
-         (for-template scheme/base "../base-env/colon.ss")
+         (for-template scheme/base "../base-env/colon.rkt")
          ;; needed at this phase for tests
-         (combine-in (prefix-in t: "../base-env/base-types-extra.ss") "../base-env/colon.ss")
-         (for-template (prefix-in t: "../base-env/base-types-extra.ss")))
+         (combine-in (prefix-in t: "../base-env/base-types-extra.rkt") "../base-env/colon.rkt")
+         (for-template (prefix-in t: "../base-env/base-types-extra.rkt")))
 
 (define-struct poly (name vars) #:prefab)
 
diff --git a/collects/typed/test-engine/racket-tests.rkt b/collects/typed/test-engine/racket-tests.rkt
index f34b794b09..a4ad8d9004 100644
--- a/collects/typed/test-engine/racket-tests.rkt
+++ b/collects/typed/test-engine/racket-tests.rkt
@@ -1,5 +1,5 @@
 #lang scheme/base
 
 (require test-engine/racket-tests
-         "type-env-ext.ss")
+         "type-env-ext.rkt")
 (provide (all-from-out test-engine/racket-tests))
diff --git a/collects/typed/test-engine/scheme-tests.rkt b/collects/typed/test-engine/scheme-tests.rkt
index a7f6bb9414..337a64bfec 100644
--- a/collects/typed/test-engine/scheme-tests.rkt
+++ b/collects/typed/test-engine/scheme-tests.rkt
@@ -1,5 +1,5 @@
 #lang scheme/base
 
 (require test-engine/scheme-tests
-         "type-env-ext.ss")
+         "type-env-ext.rkt")
 (provide (all-from-out test-engine/scheme-tests))
diff --git a/collects/version/check.rkt b/collects/version/check.rkt
index 7a3c706acf..aefa793578 100644
--- a/collects/version/check.rkt
+++ b/collects/version/check.rkt
@@ -3,10 +3,10 @@
 (define version-url "http://download.racket-lang.org/version.txt")
 (define timeout 30)
 
-(require "utils.ss")
+(require "utils.rkt")
 
 ;; This file can be invoked from an installer, and in case it's
-;; without zo files using net/url.ss is extremely slow.  Instead, do
+;; without zo files using `net/url' is extremely slow.  Instead, do
 ;; things directly.
 ;; (require net/url)
 ;; (define (url->port url) (get-pure-port (string->url url)))
diff --git a/collects/version/info.rkt b/collects/version/info.rkt
index fa78d70bbd..eb839f6fbb 100644
--- a/collects/version/info.rkt
+++ b/collects/version/info.rkt
@@ -1,6 +1,6 @@
 #lang setup/infotab
 
-(define tools (list "tool.ss"))
+(define tools (list "tool.rkt"))
 (define tool-names (list "Version"))
 
 (define scribblings '(("version.scrbl" () (tool-library))))
diff --git a/collects/version/tool.rkt b/collects/version/tool.rkt
index 9e3ee3f6c5..aef894c80b 100644
--- a/collects/version/tool.rkt
+++ b/collects/version/tool.rkt
@@ -2,8 +2,8 @@
 
 (require scheme/unit scheme/class framework drscheme/tool
          browser/external string-constants
-         "patchlevel.ss"
-         "check.ss")
+         "patchlevel.rkt"
+         "check.rkt")
 
 (define download-url "http://download.racket-lang.org/")
 
diff --git a/collects/waterworld/waterworld.rkt b/collects/waterworld/waterworld.rkt
index 4ecaef6995..45ffd98871 100644
--- a/collects/waterworld/waterworld.rkt
+++ b/collects/waterworld/waterworld.rkt
@@ -8,26 +8,25 @@
   
   (define *progname* "WaterWorld")
 
-  (define *prefs-file* 
-	(let*-values 
-	 ([(sys-prefs-file) (find-system-path 'pref-file)]
-	  [(prefs-dir nm mbd) (split-path sys-prefs-file)])
-	 (build-path prefs-dir ".ww-prefs.ss")))
+  (define *prefs-file*
+    (let*-values ([(sys-prefs-file) (find-system-path 'pref-file)]
+                  [(prefs-dir nm mbd) (split-path sys-prefs-file)])
+      (build-path prefs-dir ".ww-prefs.rktd")))
 
   (define (get-ww-pref sym default)
     (get-preference sym (lambda () default) #t *prefs-file*))
 
   (define (put-ww-prefs ss)
     (let ([syms (map car ss)]
-	  [vals (map cadr ss)])
+          [vals (map cadr ss)])
       (put-preferences syms vals
-		       (lambda _
-			 (message-box
-			  "WaterWorld error"
-			  "Error saving preferences"
-			  #f
-			  '(ok)))
-		       *prefs-file*)))
+                       (lambda _
+                         (message-box
+                          "WaterWorld error"
+                          "Error saving preferences"
+                          #f
+                          '(ok)))
+                       *prefs-file*)))
 
   ; base dimensions
   (define *base-tile-edge-length* 48) ; length of triangular tile edge
@@ -1247,9 +1246,9 @@
 			       (build-path (collection-path "waterworld") 
 					   "games"))
 			   #f
-			   "ss"
+			   "rkt"
 			   '()
-			   '(("Scheme files" "*.ss")))])
+			   '(("Racket files" "*.rkt")))])
 		  (when fn
 			(let-values 
 			 ([(base n d) (split-path fn)])
diff --git a/collects/wxme/cache-image.rkt b/collects/wxme/cache-image.rkt
index 7e2dbefcee..1ae1e31d3e 100644
--- a/collects/wxme/cache-image.rkt
+++ b/collects/wxme/cache-image.rkt
@@ -1,7 +1,6 @@
-
 (module cache-image mzscheme
   (require mzlib/class
-           "wxme.ss")
+           "wxme.rkt")
 
   (provide reader
            cache-image%)
diff --git a/collects/wxme/comment.rkt b/collects/wxme/comment.rkt
index a3eb5cf044..d72ff94ed2 100644
--- a/collects/wxme/comment.rkt
+++ b/collects/wxme/comment.rkt
@@ -1,9 +1,8 @@
-
 (module comment mzscheme
   (require mzlib/class
            mzlib/string
-           "wxme.ss"
-           "private/readable-editor.ss")
+           "wxme.rkt"
+           "private/readable-editor.rkt")
 
   (provide reader
            comment-editor%)
diff --git a/collects/wxme/editor.rkt b/collects/wxme/editor.rkt
index 6c88a7684a..c6675e9140 100644
--- a/collects/wxme/editor.rkt
+++ b/collects/wxme/editor.rkt
@@ -1,7 +1,6 @@
-
 (module editor mzscheme
   (require mzlib/class
-           "private/class-help.ss")
+           "private/class-help.rkt")
 
   (provide editor%)
 
diff --git a/collects/wxme/image.rkt b/collects/wxme/image.rkt
index 24e3dba79b..241de1ee67 100644
--- a/collects/wxme/image.rkt
+++ b/collects/wxme/image.rkt
@@ -1,7 +1,7 @@
 #lang racket/base
 (require racket/class
          racket/snip
-         "private/class-help.ss")
+         "private/class-help.rkt")
 
 (provide image%)
 
diff --git a/collects/wxme/main.rkt b/collects/wxme/main.rkt
index 8d891c33a8..44908f0a8f 100644
--- a/collects/wxme/main.rkt
+++ b/collects/wxme/main.rkt
@@ -1,4 +1,4 @@
 #lang scheme/base
 
-(require "wxme.ss")
-(provide (all-from-out "wxme.ss"))
+(require "wxme.rkt")
+(provide (all-from-out "wxme.rkt"))
diff --git a/collects/wxme/number.rkt b/collects/wxme/number.rkt
index 48d1dcf247..b59ffde335 100644
--- a/collects/wxme/number.rkt
+++ b/collects/wxme/number.rkt
@@ -1,7 +1,6 @@
-
 (module number mzscheme
   (require mzlib/class
-           "wxme.ss")
+           "wxme.rkt")
 
   (provide reader)
 
diff --git a/collects/wxme/private/readable-editor.rkt b/collects/wxme/private/readable-editor.rkt
index 5317725b99..d5673e0dad 100644
--- a/collects/wxme/private/readable-editor.rkt
+++ b/collects/wxme/private/readable-editor.rkt
@@ -1,9 +1,8 @@
-
 (module readable-editor mzscheme
   (require mzlib/class
            mzlib/struct
-           "../wxme.ss"
-           "../editor.ss")
+           "../wxme.rkt"
+           "../editor.rkt")
 
   (provide readable-editor%
            editor-reader%)
diff --git a/collects/wxme/read.rkt b/collects/wxme/read.rkt
index a3fcbbadd6..288d39d096 100644
--- a/collects/wxme/read.rkt
+++ b/collects/wxme/read.rkt
@@ -1,7 +1,5 @@
-
 (module read mzscheme
-  (require "wxme.ss")
+  (require "wxme.rkt")
 
   (provide (rename wxme-read read)
            (rename wxme-read-syntax read-syntax)))
-
diff --git a/collects/wxme/scheme.rkt b/collects/wxme/scheme.rkt
index 6e98661f5e..ddc264a0cd 100644
--- a/collects/wxme/scheme.rkt
+++ b/collects/wxme/scheme.rkt
@@ -1,13 +1,12 @@
-
 (module scheme mzscheme
   (require mzlib/class
-           "wxme.ss"
-           "editor.ss"
-           "private/readable-editor.ss")
+           "wxme.rkt"
+           "editor.rkt"
+           "private/readable-editor.rkt")
 
   (provide reader 
            scheme-editor%)
-  
+
   (define scheme-editor% (class readable-editor% (super-new)))
 
   (define reader
diff --git a/collects/wxme/test-case.rkt b/collects/wxme/test-case.rkt
index aa2d642aab..441cc1e6a5 100644
--- a/collects/wxme/test-case.rkt
+++ b/collects/wxme/test-case.rkt
@@ -1,8 +1,7 @@
-
 (module test-case mzscheme
   (require mzlib/class
-           "wxme.ss"
-           "private/class-help.ss")
+           "wxme.rkt"
+           "private/class-help.rkt")
 
   (provide reader
            test-case%)
diff --git a/collects/wxme/text.rkt b/collects/wxme/text.rkt
index 9ea03e439c..cd751f3462 100644
--- a/collects/wxme/text.rkt
+++ b/collects/wxme/text.rkt
@@ -1,9 +1,8 @@
-
 (module text mzscheme
   (require mzlib/class
-           "wxme.ss"
-           "editor.ss"
-           "private/readable-editor.ss")
+           "wxme.rkt"
+           "editor.rkt"
+           "private/readable-editor.rkt")
 
   (provide reader
            text-editor%)
diff --git a/collects/wxme/wxme.rkt b/collects/wxme/wxme.rkt
index 0183c46f00..210000e99b 100644
--- a/collects/wxme/wxme.rkt
+++ b/collects/wxme/wxme.rkt
@@ -1,4 +1,3 @@
-
 (module wxme mzscheme
   (require mzlib/port
            mzlib/string
@@ -9,9 +8,9 @@
            scheme/gui/dynamic
            syntax/modread
            (only racket/snip/private/snip int->img-type)
-           "image.ss"
-           "editor.ss"
-           "private/compat.ss")
+           "image.rkt"
+           "editor.rkt"
+           "private/compat.rkt")
 
   (define (decode who port snip-filter close? skip-content?)
     (expect #rx#"^WXME" port who "does not start with \"WXME\"")
diff --git a/collects/wxme/xml.rkt b/collects/wxme/xml.rkt
index c1218b36ae..6b91f71c10 100644
--- a/collects/wxme/xml.rkt
+++ b/collects/wxme/xml.rkt
@@ -1,11 +1,10 @@
-
 (module xml mzscheme
   (require mzlib/class
            xml/xml
            mzlib/list
-           "wxme.ss"
-           "editor.ss"
-           "private/readable-editor.ss")
+           "wxme.rkt"
+           "editor.rkt"
+           "private/readable-editor.rkt")
 
   (provide reader
            xml-editor%)
@@ -31,7 +30,7 @@
 
            (super-new))))
 
-  ;; FIXME! Copied from xml-snip-helpers.ss verbatim
+  ;; FIXME! Copied from xml-snip-helpers.rkt verbatim
   (define (eliminate-whitespace-in-empty-tags xexpr)
     (cond
      [(and (pair? xexpr)
diff --git a/collects/xml/info.rkt b/collects/xml/info.rkt
index d1ff856ec4..4319a666bc 100644
--- a/collects/xml/info.rkt
+++ b/collects/xml/info.rkt
@@ -1,7 +1,7 @@
 #lang setup/infotab
 
 ;; the XML tool has been moved to the stepper collection, so that the
-;; stepper can create xml snips.  See collects/stepper/tool.ss for (a
+;; stepper can create xml snips.  See collects/stepper/tool.rkt for (a
 ;; bit) more information
 (define tools '(("text-box-tool.rkt")))
 (define tool-names '("Text Box"))