diff --git a/collects/2htdp/private/checked-cell.rkt b/collects/2htdp/private/checked-cell.rkt
index 8136aed963..0f69390edc 100644
--- a/collects/2htdp/private/checked-cell.rkt
+++ b/collects/2htdp/private/checked-cell.rkt
@@ -15,14 +15,13 @@
 
 (define checked-cell% 
   (class* object% (checked-cell<%>) 
-    (init-field msg    ;; String 
-                value0 ;; X
+    (init-field value0 ;; X
                 ok?)   ;; Any -> Boolean : X 
     
     (init [display #f]) ;; (U String #f) ; a string is the name of the state display window
     
     (field 
-     [value (coerce "initial value" value0)]
+     [value (coerce "the initial expression" value0 #t)]
      ;; (U False pasteboard%)
      [pb (if (boolean? display)
              #f
@@ -63,10 +62,15 @@
                   (read-all)))))))
     
     ;; Symbol Any -> ok?
-    (define/private (coerce tag nw)
+    (define/private (coerce tag nw [say-evaluated-to #f])
       (let ([b (ok? nw)])
-        (check-result "check-with predicate" boolean? "Boolean" b)
-        (check-result tag (lambda _ b) (format "~a (see check-with)" msg) nw)
+        (unless (boolean? b)
+          (tp-error 'check-with "the test function ~a is expected to return a boolean, but it returned ~v" 
+                    (object-name ok?) b))
+        (unless b
+          (tp-error 'check-with "~a ~a ~v, which fails to pass check-with's ~a test"
+                    tag (if say-evaluated-to "evaluated to" "returned") 
+                    nw (object-name ok?)))
         nw))
     
     ;; Symbol Any -> Void 
diff --git a/collects/2htdp/private/clauses-spec-and-process.rkt b/collects/2htdp/private/clauses-spec-and-process.rkt
index 36b85595bd..04adcdbbea 100644
--- a/collects/2htdp/private/clauses-spec-and-process.rkt
+++ b/collects/2htdp/private/clauses-spec-and-process.rkt
@@ -72,10 +72,9 @@
   
   if anything fails, use the legal keyword to specialize the error message
 |#
-(define (->args tag stx state0 clauses Spec ->rec? legal)
-  (define msg (format "not a legal clause in a ~a description" legal))
+(define (->args tag stx state0 clauses Spec ->rec?)
   (define kwds (map (compose (curry datum->syntax stx) car) Spec))
-  (define spec (clauses-use-kwd (syntax->list clauses) ->rec? msg kwds))
+  (define spec (clauses-use-kwd (syntax->list clauses) ->rec? tag kwds))
   (duplicates? tag spec)
   (not-a-clause tag stx state0 kwds)
   (map (lambda (s) 
@@ -93,20 +92,21 @@
        Spec))
 
 ;; check whether rec? occurs, produce list of keyword x clause pairs 
-(define (clauses-use-kwd stx:list ->rec? legal-clause kwds)
+(define (clauses-use-kwd stx:list ->rec? tag kwds)
   (define kwd-in? (->kwds-in kwds))
-  (define double (string-append legal-clause ", ~a has been redefined"))
   (map (lambda (stx)
          (syntax-case stx ()
            [(kw . E) (kwd-in? #'kw) (begin (->rec? #'kw #'E) (cons #'kw stx))]
            [(kw . E)
             (let ([kw (syntax-e #'kw)])
               (if (member kw (map syntax-e kwds))
-                  (raise-syntax-error #f (format double kw) stx)
-                  (raise-syntax-error #f legal-clause stx)))]
-           [_ (raise-syntax-error #f legal-clause stx)]))
+                  (raise-syntax-error tag (format "the ~a clause appears twice" kw) stx)
+                  (raise-syntax-error tag (format "~a clauses are not allowed when using ~a" kw tag)
+                                      stx)))]
+           [_ (raise-syntax-error tag "expected a clause, but found something else" stx)]))
        stx:list))
 
+
 ;; [Listof SyntaxIdentifier] -> (Syntax -> Boolean)
 (define (->kwds-in kwds)
   (lambda (k)
@@ -118,7 +118,7 @@
   (syntax-case state0 ()
     [(kw . E) 
      ((->kwds-in kwds) #'kw) 
-     (raise-syntax-error tag "missing initial state" stx)]
+     (raise-syntax-error tag "expected an initial state, but found a clause" stx)]
     [_ #t]))
 
 ;; Symbol [Listof kw] -> true
diff --git a/collects/2htdp/private/universe.rkt b/collects/2htdp/private/universe.rkt
index ebf6190eaa..1b614cb674 100644
--- a/collects/2htdp/private/universe.rkt
+++ b/collects/2htdp/private/universe.rkt
@@ -67,7 +67,7 @@
       
       (field 
        [universe 
-        (new checked-cell% [msg "UniSt"] [value0 universe0] [ok? check-with] 
+        (new checked-cell% [value0 universe0] [ok? check-with] 
              [display (if (string? state) state (and state  "your server's state"))])])
  
       ;; -----------------------------------------------------------------------
@@ -87,7 +87,7 @@
 	      (define n (if (object-name name) (object-name name) name))
               (define-values (u mails bad) 
                 (bundle> n (name (send universe get) a ...)))
-              (send universe set (format "~a callback" 'name) u)
+              (send universe set (format "value returned from ~a" 'name) u)
               (unless (boolean? to-string) (send gui add (to-string u)))
               (broadcast mails)
               (for-each (lambda (iw)
@@ -120,7 +120,7 @@
         (kill iworld))
       
       ;; tick, tock : deal with a tick event for this world 
-      (def/cback pubment (ptock) (lambda (w) (pptock w)))
+      (def/cback pubment (ptock) (let ([on-tick (lambda (w) (pptock w))]) on-tick))
       (define/public (pptock w) (void))
       
       ;; IWorld -> Void 
@@ -179,7 +179,7 @@
                 (loop))))
           ;; --- go universe go ---
           (set! iworlds '())
-          (send universe set "initial value" universe0)
+          (send universe set "initial expression" universe0)
           (send gui add "a new universe is up and running")
           (thread loop)))
       
@@ -363,10 +363,7 @@
 ;; Symbol Any ->* Universe [Listof Mail] [Listof IWorld]
 (define (bundle> tag r)
   (unless (bundle? r) 
-    (raise
-      (make-exn
-	(format "error: bundle expected from ~a, given: ~e" tag r)
-	(current-continuation-marks))))
+    (tp-error tag "expected the ~a function to return a bundle, but it returned ~e" tag r))
   (values (bundle-state r) (bundle-mails r) (bundle-bad r)))
 
 (define-struct mail (to content) #:transparent)
diff --git a/collects/2htdp/private/world.rkt b/collects/2htdp/private/world.rkt
index 92638e1347..293b2c272e 100644
--- a/collects/2htdp/private/world.rkt
+++ b/collects/2htdp/private/world.rkt
@@ -59,7 +59,7 @@
       (field
        [to-draw on-draw]
        [world
-        (new checked-cell% [msg "World"] [value0 world0] [ok? check-with]
+        (new checked-cell% [value0 world0] [ok? check-with]
              [display (and state (or name "your world program's state"))])])
       
       
@@ -256,7 +256,7 @@
             (queue-callback 
              (lambda ()
                (with-handlers ([exn? (handler #t)])
-                 (define tag (format "~a callback" 'transform))
+                 (define tag (object-name transform))
                  (define nw (transform (send world get) arg ...))
                  (define (d) (pdraw) (set-draw#!))
                  ;; ---
diff --git a/collects/2htdp/tests/on-tick-defined.rkt b/collects/2htdp/tests/on-tick-defined.rkt
index 2946379b5f..bec034fb80 100644
--- a/collects/2htdp/tests/on-tick-defined.rkt
+++ b/collects/2htdp/tests/on-tick-defined.rkt
@@ -6,9 +6,9 @@
 
 (error-print-source-location #f)
 
-(define legal "~a: not a legal clause in a world description")
+(define legal "big-bang: ~a clauses are not allowed when using big-bang")
 (define double 
-  (string-append (format legal 'on-tick) ", on-tick has been redefined"))
+  "big-bang: the on-tick clause appears twice")
 
 (with-handlers ((exn:fail:syntax? 
                  (lambda (x) 
@@ -33,7 +33,8 @@
 
 (with-handlers ((exn:fail:syntax? 
                  (lambda (e)
-                   (unless (string=? (exn-message e) (format legal 'stop-when))
+                   (unless (string=? (exn-message e) 
+                                     "big-bang: expected a clause, but found something else")
                      (raise e)))))
   (eval '(module a scheme
            (require 2htdp/universe)
@@ -44,7 +45,7 @@
 
 (with-handlers ((exn:fail:syntax? 
                  (lambda (x) 
-                   (unless (string=? (exn-message x) "big-bang: missing initial state")
+                   (unless (string=? (exn-message x) "big-bang: expected an initial state, but found a clause")
                      (raise x)))))
   (eval '(module a scheme 
            (require 2htdp/universe)
@@ -52,7 +53,7 @@
 
 (with-handlers ((exn:fail:syntax? 
                  (lambda (x) 
-                   (unless (string=? (exn-message x) "universe: missing initial state")
+                   (unless (string=? (exn-message x) "universe: expected an initial state, but found a clause")
                      (raise x)))))
   (eval '(module a scheme 
            (require 2htdp/universe)
diff --git a/collects/2htdp/tests/test-image.rkt b/collects/2htdp/tests/test-image.rkt
index 2fb0eda246..26bc640223 100644
--- a/collects/2htdp/tests/test-image.rkt
+++ b/collects/2htdp/tests/test-image.rkt
@@ -1972,60 +1972,60 @@
 
 (test/exn (rectangle 10 10 "solid" (make-pen "black" 12 "solid" "round" "round"))
           =>
-          #rx"^rectangle: expected <image-color>")
+          #rx"^rectangle: expects a image-color")
 
 (test/exn (rectangle 10 10 'solid (make-pen "black" 12 "solid" "round" "round"))
           =>
-          #rx"^rectangle: expected <image-color>")
+          #rx"^rectangle: expects a image-color")
 
 (test/exn (circle 10 'solid (make-pen "black" 12 "solid" "round" "round"))
           =>
-          #rx"^circle: expected <image-color>")
+          #rx"^circle: expects a image-color")
 
 (test/exn (ellipse 10 10 'solid (make-pen "black" 12 "solid" "round" "round"))
           =>
-          #rx"^ellipse: expected <image-color>")
+          #rx"^ellipse: expects a image-color")
 
 (test/exn (triangle 10 'solid (make-pen "black" 12 "solid" "round" "round"))
           =>
-          #rx"^triangle: expected <image-color>")
+          #rx"^triangle: expects a image-color")
 
 (test/exn (right-triangle 10 12 'solid (make-pen "black" 12 "solid" "round" "round"))
           =>
-          #rx"^right-triangle: expected <image-color>")
+          #rx"^right-triangle: expects a image-color")
 
 (test/exn (isosceles-triangle 10 120 'solid (make-pen "black" 12 "solid" "round" "round"))
           =>
-          #rx"^isosceles-triangle: expected <image-color>")
+          #rx"^isosceles-triangle: expects a image-color")
 
 (test/exn (square 10 'solid (make-pen "black" 12 "solid" "round" "round"))
           =>
-          #rx"^square: expected <image-color>")
+          #rx"^square: expects a image-color")
 
 (test/exn (rhombus 40 45 'solid (make-pen "black" 12 "solid" "round" "round"))
           =>
-          #rx"^rhombus: expected <image-color>")
+          #rx"^rhombus: expects a image-color")
 
 (test/exn (regular-polygon 40 6 'solid (make-pen "black" 12 "solid" "round" "round"))
           =>
-          #rx"^regular-polygon: expected <image-color>")
+          #rx"^regular-polygon: expects a image-color")
 
 (test/exn (star 40 'solid (make-pen "black" 12 "solid" "round" "round"))
           =>
-          #rx"^star: expected <image-color>")
+          #rx"^star: expects a image-color")
 
 (test/exn (star-polygon 40 7 3 'solid (make-pen "black" 12 "solid" "round" "round"))
           =>
-          #rx"^star-polygon: expected <image-color>")
+          #rx"^star-polygon: expects a image-color")
 
 (test/exn (polygon (list (make-posn 0 0) (make-posn 100 0) (make-posn 100 100))
                    'solid (make-pen "black" 12 "solid" "round" "round"))
           =>
-          #rx"^polygon: expected <image-color>")
+          #rx"^polygon: expects a image-color")
 (test/exn (polygon (list (make-posn 0 0+1i) (make-posn 100 0) (make-posn 100 100))
                    'solid (make-pen "black" 12 "solid" "round" "round"))
           =>
-          #rx"^polygon: expected <list-of-posns-with-real-valued-x-and-y-coordinates>")
+          #rx"^polygon: expects a list-of-posns-with-real-valued-x-and-y-coordinates")
 
 
 (test/exn (save-image "tri.png" (triangle 50 "solid" "purple"))
diff --git a/collects/2htdp/universe.rkt b/collects/2htdp/universe.rkt
index 1b0e61c7d5..7d382c7049 100644
--- a/collects/2htdp/universe.rkt
+++ b/collects/2htdp/universe.rkt
@@ -218,7 +218,7 @@
     "wheel-down"))
 
 (define-syntax (big-bang stx)
-  (define world0 "big-bang needs at least an initial world")
+  (define world0 "expects an expression for the initial world and at least one clause, but nothing's there")
   (syntax-case stx ()
     [(big-bang) (raise-syntax-error #f world0 stx)]
     [(big-bang w clause ...)
@@ -230,11 +230,11 @@
                    [(V) (set! rec? #'V)]
                    [_ (err '#'record? stx)])))]
             [args 
-             (->args 'big-bang stx #'w #'(clause ...) WldSpec ->rec? "world")]
+             (->args 'big-bang stx #'w #'(clause ...) WldSpec ->rec?)]
             [dom (syntax->list #'(clause ...))])
        (cond
          [(and (not (contains-clause? #'to-draw dom)) (not (contains-clause? #'on-draw dom)))
-          (raise-syntax-error #f "missing to-draw clause" stx)]
+          (raise-syntax-error #f "expects at least one clause after the initial world, but nothing's there" stx)]
          [else 
           (stepper-syntax-property
            #`(run-it ((new-world (if #,rec? aworld% world%)) w #,@args))
@@ -248,7 +248,7 @@
 
 (define (run-movie r m*)
   (check-arg 'run-movie (positive? r) "positive number" "first" r)
-  (check-arg 'run-movie (list? m*) "list (of images)" "second" m*)
+  (check-arg 'run-movie (list? m*) "list of images" "second" m*)
   (for-each (lambda (m) (check-image 'run-movie m "first" "list of images")) m*)
   (let* ([fst (car m*)]
          [wdt (image-width fst)]
@@ -314,16 +314,16 @@
 
 (define-syntax (universe stx)
   (syntax-case stx ()
-    [(universe) (raise-syntax-error #f "not a legal universe description" stx)]
-    [(universe u) (raise-syntax-error #f "not a legal universe description" stx)]
+    [(universe) (raise-syntax-error #f "expects an expression for the initial world and at least one clause, but nothing's there" stx)]
+    [(universe u) (raise-syntax-error #f "expects at least one clause after the initial world, but nothing's there" stx)]
     [(universe u bind ...)
-     (let* ([args (->args 'universe stx #'u #'(bind ...) UniSpec void "universe")]
+     (let* ([args (->args 'universe stx #'u #'(bind ...) UniSpec void)]
             [dom (syntax->list #'(bind ...))])
        (cond
          [(not (contains-clause? #'on-new dom))
-          (raise-syntax-error #f "missing on-new clause" stx)]
+          (raise-syntax-error #f "expects a on-new clause, but found none" stx)]
          [(not (contains-clause? #'on-msg dom))
-          (raise-syntax-error #f "missing on-msg clause" stx)]
+          (raise-syntax-error #f "expects a on-msg clause, but found none" stx)]
          [else ; (and (memq #'on-new dom) (memq #'on-msg dom))
           #`(run-it ((new-universe universe%) u #,@args))]))]))
 
diff --git a/collects/htdp/error.rkt b/collects/htdp/error.rkt
index 73e9d20acd..9708d75dc4 100644
--- a/collects/htdp/error.rkt
+++ b/collects/htdp/error.rkt
@@ -1,12 +1,14 @@
 #lang scheme/base
-(require scheme/class)
+(require scheme/class
+         lang/private/rewrite-error-message)
 
 ;; --------------------------------------------------------------------------
 (provide check-arg check-arity check-proc check-result 
          check-list-list check-color
          check-fun-res check-dependencies
          natural?
-         find-non tp-exn? number->ord)
+         find-non tp-exn? number->ord
+         tp-error)
 
 (define (natural? w)
   (and (number? w) (integer? w) (>= w 0)))
@@ -79,7 +81,7 @@
 (define (check-result pname pred? expected given . other-given)
   (if (pred? given)
       given
-      (tp-error pname "result of type <~a> expected, your function produced ~a" expected 
+      (tp-error pname "is expected to return a ~a, but it returned ~v" expected 
                 (if (pair? other-given)
                     (car other-given)
                     given))))
@@ -112,7 +114,7 @@
 ;; check-arg : sym bool str (or/c str non-negative-integer) TST -> void
 (define (check-arg pname condition expected arg-posn given)
   (unless condition
-    (tp-error pname "expected <~a> as ~a argument, given: ~e"
+    (tp-error pname "expects a ~a as ~a argument, given: ~e"
               expected 
               (spell-out arg-posn)
               given)))
@@ -121,16 +123,16 @@
 (define (check-arity name arg# args)
   (if (= (length args) arg#)
       (void)
-      (tp-error name "expects ~a arguments, given ~e" arg# (length args))))
+      (tp-error name (argcount-error-message arg# (length args)))))
 
 ;; check-proc :
 ;;   sym (... *->* ...) num (union sym str) (union sym str) -> void
 (define (check-proc proc f exp-arity arg# arg-err)
   (unless (procedure? f)
-    (tp-error proc "procedure expected as ~a argument; given ~e" arg# f))
+    (tp-error proc "expected a function as ~a argument; given ~e" arg# f))
   (let ([arity-of-f (procedure-arity f)])
     (unless (procedure-arity-includes? f exp-arity) ; (and (number? arity-of-f) (>= arity-of-f exp-arity))
-      (tp-error proc "procedure of ~a expected as ~a argument; given procedure of ~a "
+      (tp-error proc "expected function of ~a as ~a argument; given function of ~a "
                 arg-err arg# 
                 (cond
                   [(number? arity-of-f)
diff --git a/collects/htdp/world.rkt b/collects/htdp/world.rkt
index f4c0bc67af..b9ca5e072d 100644
--- a/collects/htdp/world.rkt
+++ b/collects/htdp/world.rkt
@@ -73,6 +73,7 @@ Matthew
          htdp/image
          mrlib/cache-image-snip
          lang/prim
+         lang/private/rewrite-error-message
          (for-syntax scheme/base))
 
 (require mrlib/gif)
@@ -180,13 +181,8 @@ Matthew
     (define args (length x))
     (if (or (= args 5) (= args 4))
         (apply big-bang0 x) 
-        (error 'big-bang msg))))
-(define msg
-  (string-append
-   "big-bang consumes 4 or 5 arguments:\n"
-   "-- (big-bang <width> <height> <rate> <world0>)\n"
-   "-- (big-bang <width> <height> <rate> <world0> <animated-gif>)\n"
-   "see Help Desk."))
+        (tp-error 'big-bang "expects 4 or 5 arguments, given ~a" args))))
+
 (define *running?* #f)
 (define big-bang0
   (case-lambda 
@@ -199,17 +195,17 @@ Matthew
      ;; ============================================
      (check-arg 'big-bang
                 (and (number? delta) (<= 0 delta 1000))
-                "number [of seconds] between 0 and 1000"
+                "number of seconds between 0 and 1000"
                 "third"
                 delta)
      (check-arg 'big-bang 
                 (boolean? animated-gif)
-                "boolean expected"
+                "boolean"
                 "fifth"
                 animated-gif)
      (let ([w (coerce w)]
            [h (coerce h)])
-       (when *running?*  (error 'big-bang "the world is still running"))
+       (when *running?*  (error 'big-bang "the world is still running, cannot start another world"))
        (set! *running?* #t)
        (callback-stop!)
        ;; (when (vw-init?) (error 'big-bang "big-bang already called once"))
@@ -288,13 +284,7 @@ Matthew
     (define args (length x))
     (if (or (= args 5) (= args 4))
         (apply run-simulation0 x) 
-        (error 'run-simulation msg-run-simulation))))
-(define msg-run-simulation
-  (string-append
-   "consumes 4 or 5 arguments:\n"
-   "-- (run-simulation <width> <height> <rate> <world-to-world-function>)\n"
-   "-- (run-simulation <width> <height> <rate> <world-to-world-function> <create-animated-gif?>)\n"
-   "see Help Desk."))
+        (tp-error 'run-simulation "expects 4 or 5 arguments, given ~a" args))))
 
 
 (define run-simulation0
@@ -343,7 +333,7 @@ Matthew
 (define (check-scene tag i rank)
   (if (image? i)
       (unless (scene? i)
-        (error tag "scene expected, given image whose pinhole is at (~s,~s) instead of (0,0)"
+        (tp-error tag "expects a scene, given image whose pinhole is at (~s,~s) instead of (0,0)"
                (pinhole-x i) (pinhole-y i)))
       (check-arg tag #f "image" rank i)))
 
@@ -415,7 +405,10 @@ Matthew
             [(lower-left)  (if (number? low) (add low h) (add 0 lft))]
             [(upper-right) (if (number? upp) (add upp 0) (add w rgt))]
             [(lower-right) (if (number? low) (add low h) (add w rgt))]
-            [else (error 'dir "contract violation: ~e" dir)])]
+            [else (tp-error
+                   'dir
+                   "expected a symbol for the direction, such as 'upper-left 'lower-right 'upper-right or 'lower-right, given ~a"
+                   dir)])]
          [(and (< 0 x1 w) (< 0 y1 h)) ;; (x1,y1) in interior; symmetry!
           (add-line-to-scene0 img x1 y1 x0 y0 c)]
          [else 
@@ -524,7 +517,7 @@ Matthew
 (define unique-world (cons 1 1))
 (define (check-world tag)
   (when (eq? unique-world the-world) 
-    (error tag "evaluate (big-bang Number Number Number World) first")))
+    (tp-error tag "big-bang has not been called before calling ~a" tag)))
 
 (define the-world unique-world)
 (define the-world0 unique-world)
@@ -696,7 +689,7 @@ Matthew
       [(tick)  (timer-callback0 world)]
       [(key)   (key-callback0 world (cadr fst))]
       [(mouse) (mouse-callback0 world (cadr fst) (caddr fst) (cadddr fst))]
-      [else (error 'play-back "bad type of event: ~s" fst)]))
+      [else (tp-error 'play-back "bad type of event: ~s" fst)]))
   ;; --- creating images 
   (define total (+ (length event-history) 1))
   (define image-count 0)
@@ -872,7 +865,7 @@ Matthew
         [(send e entering?)    'enter]
         [(send e leaving?)     'leave]
         [else ; (send e get-event-type)
-         (error 'on-mouse-event
+         (tp-error 'on-mouse-event
                 (format 
                  "Unknown event type: ~a"
                  (send e get-event-type)))]))
diff --git a/collects/lang/private/teach.rkt b/collects/lang/private/teach.rkt
index 7ef6294af8..4c6988b391 100644
--- a/collects/lang/private/teach.rkt
+++ b/collects/lang/private/teach.rkt
@@ -64,7 +64,6 @@
 		      syntax/stx
 		      syntax/struct
 		      syntax/context
-                      syntax/colored-errors
 		      mzlib/include
 		      scheme/list
 		      (rename racket/base racket:define-struct define-struct)
diff --git a/collects/tests/drracket/language-test.rkt b/collects/tests/drracket/language-test.rkt
index ee0e868024..2d43726807 100644
--- a/collects/tests/drracket/language-test.rkt
+++ b/collects/tests/drracket/language-test.rkt
@@ -1015,7 +1015,7 @@ the settings above should match r5rs
                      "(void)" 
                      "qqq: this name was defined previously and cannot be re-defined\n(void)")
     (test-expression "(cond [(= 1 2) 3])" "cond: all question results were false")
-    (test-expression "(cons 1 2)"   "cons: second argument must be a list or cyclic list, but received 1 and 2")
+    (test-expression "(cons 1 2)"  "cons: second argument must be a list, but received 1 and 2")
     (test-expression "(+ (list 1) 2)" "+: expects a number as 1st argument, given (list 1)")
     (test-expression "'(1)" 
                      "(list 1)"
diff --git a/collects/tests/drracket/repl-test.rkt b/collects/tests/drracket/repl-test.rkt
index ca6b12c0bc..83b51dbcec 100644
--- a/collects/tests/drracket/repl-test.rkt
+++ b/collects/tests/drracket/repl-test.rkt
@@ -79,7 +79,6 @@ This produces an ACK message
 
 (define test-data
   (list
-   #|
    ;; basic tests
    (mktest "1"
            ("1"
@@ -611,7 +610,7 @@ This produces an ACK message
            #f
            void
            void)
-   |#
+
    ;; error escape handler test
    (mktest
     "(let ([old (error-escape-handler)])\n(+ (let/ec k\n(dynamic-wind\n(lambda () (error-escape-handler (lambda () (k 5))))\n(lambda () (expt 3 #f))\n(lambda () (error-escape-handler old))))\n10))"