diff --git a/collects/unstable/bytes.rkt b/collects/unstable/bytes.rkt
index c871642225..b33d4f51a9 100644
--- a/collects/unstable/bytes.rkt
+++ b/collects/unstable/bytes.rkt
@@ -1,5 +1,6 @@
-#lang racket
-(require racket/serialize)
+#lang racket/base
+(require racket/contract
+         racket/serialize)
 
 (provide/contract
  [read/bytes (bytes? . -> . serializable?)]
diff --git a/collects/unstable/debug.rkt b/collects/unstable/debug.rkt
index c7ab5e30d5..7c0b362e71 100644
--- a/collects/unstable/debug.rkt
+++ b/collects/unstable/debug.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 (provide debug
          dprintf
@@ -20,11 +20,12 @@
          parameterize/debug)
 
 (require racket/block
+         racket/match
          unstable/pretty
          unstable/srcloc
          unstable/location
          unstable/syntax
-         (for-syntax racket/match syntax/parse unstable/syntax))
+         (for-syntax racket/base racket/match syntax/parse unstable/syntax))
 
 (define-syntax (let/debug stx)
   (syntax-parse stx
diff --git a/collects/unstable/define.rkt b/collects/unstable/define.rkt
index 6060426ce1..7ea40e0100 100644
--- a/collects/unstable/define.rkt
+++ b/collects/unstable/define.rkt
@@ -1,6 +1,7 @@
-#lang racket
+#lang racket/base
 
-(require (for-syntax racket/list
+(require (for-syntax racket/base
+                     racket/list
                      racket/match
                      syntax/kerncase
                      unstable/syntax))
diff --git a/collects/unstable/gui/slideshow.rkt b/collects/unstable/gui/slideshow.rkt
index 6d80f38266..f2ba379f1f 100644
--- a/collects/unstable/gui/slideshow.rkt
+++ b/collects/unstable/gui/slideshow.rkt
@@ -1,9 +1,11 @@
-#lang racket
+#lang racket/base
 
 (require slideshow/base slideshow/pict
+         racket/contract racket/list racket/match
          racket/splicing racket/stxparam racket/gui/base
          racket/block racket/class
-         unstable/define)
+         unstable/define
+         (for-syntax scheme/base))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;
@@ -304,7 +306,7 @@
  [strike (->* [pict?] [any/c] pict?)]
  [shade (->* [pict?] [any/c #:ratio (real-in 0 1)] pict?)])
 (provide staged slide/staged stage stage-name
-         before at after before/at at/after except
+         before at after before/at at/after
          pict-if pict-cond pict-case pict-match
          pict-combine with-pict-combine)
 
diff --git a/collects/unstable/hash.rkt b/collects/unstable/hash.rkt
index 34bcc14293..4365ed43cd 100644
--- a/collects/unstable/hash.rkt
+++ b/collects/unstable/hash.rkt
@@ -1,6 +1,5 @@
-#lang racket
-
-(require (for-syntax syntax/parse))
+#lang racket/base
+(require racket/contract)
 
 ;; Eli: See comments for `dict-ref/check' and relatives.
 
diff --git a/collects/unstable/markparam.rkt b/collects/unstable/markparam.rkt
index 90d3027c5f..8b400fd6a8 100644
--- a/collects/unstable/markparam.rkt
+++ b/collects/unstable/markparam.rkt
@@ -1,5 +1,8 @@
-#lang racket
-(require racket/serialize)
+#lang racket/base
+(require racket/serialize
+         racket/function
+         racket/contract
+         (for-syntax racket/base))
 
 (define mark-parameter-first
   (curry continuation-mark-set-first #f))
diff --git a/collects/unstable/path.rkt b/collects/unstable/path.rkt
index 0ed877ca13..a6967c8f1a 100644
--- a/collects/unstable/path.rkt
+++ b/collects/unstable/path.rkt
@@ -1,10 +1,11 @@
-#lang racket
-(require unstable/list
+#lang racket/base
+(require racket/contract
+         unstable/list
          unstable/contract)
 
 ; explode-path* : path? -> (listof path?)
 (define (explode-path* p)
-  (let loop ([p p] [r empty])
+  (let loop ([p p] [r null])
     (cond 
       [(eq? 'relative p) r]
       [(not p) r]
diff --git a/collects/unstable/planet.rkt b/collects/unstable/planet.rkt
index 60a5e9d70f..b7ef1aa891 100644
--- a/collects/unstable/planet.rkt
+++ b/collects/unstable/planet.rkt
@@ -1,6 +1,6 @@
-#lang racket
+#lang racket/base
 
-(require (for-syntax unstable/planet-syntax)
+(require (for-syntax racket/base unstable/planet-syntax)
          unstable/planet-syntax
          unstable/require)
 
diff --git a/collects/unstable/port.rkt b/collects/unstable/port.rkt
index 89710d8a57..87ef299e5b 100644
--- a/collects/unstable/port.rkt
+++ b/collects/unstable/port.rkt
@@ -1,5 +1,7 @@
-#lang racket
-(require unstable/srcloc)
+#lang racket/base
+(require racket/match
+         racket/contract
+         unstable/srcloc)
 
 #|
 Ryan:
diff --git a/collects/unstable/require.rkt b/collects/unstable/require.rkt
index ea536f96c2..c98dcffe75 100644
--- a/collects/unstable/require.rkt
+++ b/collects/unstable/require.rkt
@@ -1,6 +1,7 @@
-#lang racket
+#lang racket/base
 
-(require (for-syntax racket/match
+(require (for-syntax racket/base
+                     racket/match
                      racket/require-transform
                      racket/provide-transform
                      syntax/parse
diff --git a/collects/unstable/sandbox.rkt b/collects/unstable/sandbox.rkt
index 76f7a4259a..e1735e3aa4 100644
--- a/collects/unstable/sandbox.rkt
+++ b/collects/unstable/sandbox.rkt
@@ -1,6 +1,7 @@
-#lang racket
+#lang racket/base
 
-(require racket/sandbox)
+(require racket/promise
+         racket/sandbox)
 
 (provide make-trusted-evaluator
          make-trusted-module-evaluator
diff --git a/collects/unstable/scribblings/dirs.scrbl b/collects/unstable/scribblings/dirs.scrbl
index a39a5e3509..99bcd08319 100644
--- a/collects/unstable/scribblings/dirs.scrbl
+++ b/collects/unstable/scribblings/dirs.scrbl
@@ -84,3 +84,5 @@ replaced by @racketresult[user], and the PLaneT cache is replaced by
 @racketresult[planet].
 
 }
+
+@close-eval[evaluator]
diff --git a/collects/unstable/scribblings/sequence.scrbl b/collects/unstable/scribblings/sequence.scrbl
index 01ad01396c..7f58c4ef0f 100644
--- a/collects/unstable/scribblings/sequence.scrbl
+++ b/collects/unstable/scribblings/sequence.scrbl
@@ -1,15 +1,18 @@
-#lang scribble/doc
-@(require scribble/base
-          scribble/manual
-          scribble/eval
-	  scribblings/reference/mz
+#lang scribble/manual
+@(require scribble/eval
 	  "utils.rkt"
-         (for-label unstable/sequence
-                    racket/contract
-                    racket/base))
+          (for-label unstable/sequence
+                     racket/contract
+                     racket/base))
 
 @(define the-eval (make-base-eval))
 @(the-eval '(require unstable/sequence))
+@(define-syntax speed
+    (syntax-rules ()
+      [(_ id what)
+       (t "An " (scheme id) " application can provide better performance for "
+          (elem what)
+          " iteration when it appears directly in a " (scheme for) " clause.")]))
 
 @title[#:tag "sequence"]{Sequences}
 
diff --git a/collects/unstable/sexp-diff.rkt b/collects/unstable/sexp-diff.rkt
index 46ffc90d7d..c8d4fff0a0 100644
--- a/collects/unstable/sexp-diff.rkt
+++ b/collects/unstable/sexp-diff.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 ;;; diff-sexp.lisp -- diffs s-expressions based on Levenshtein-like edit distance.
 
@@ -45,6 +45,8 @@
 
 ;;; Code:
 
+(require racket/list)
+
 (provide sexp-diff)
 
 ;; Computes the number of atoms contained in TREE.
diff --git a/collects/unstable/string.rkt b/collects/unstable/string.rkt
index 8b8eabc92a..cd5ad807a3 100644
--- a/collects/unstable/string.rkt
+++ b/collects/unstable/string.rkt
@@ -1,5 +1,6 @@
-#lang racket
-(require racket/serialize)
+#lang racket/base
+(require racket/contract
+         racket/serialize)
 
 (define (read/string str)
   (read (open-input-string str)))
diff --git a/collects/unstable/web.rkt b/collects/unstable/web.rkt
index 001a962337..0864fba011 100644
--- a/collects/unstable/web.rkt
+++ b/collects/unstable/web.rkt
@@ -1,5 +1,6 @@
-#lang racket
+#lang racket/base
 (require xml
+         racket/contract
          unstable/function
          unstable/text)