diff --git a/src/mzscheme/src/exnsrc.ss b/src/mzscheme/src/exnsrc.ss
index 3882ada404..2742ce6ea2 100644
--- a/src/mzscheme/src/exnsrc.ss
+++ b/src/mzscheme/src/exnsrc.ss
@@ -1,3 +1,4 @@
+#lang scheme
 
 #|
 
@@ -7,47 +8,49 @@ propeties (the latter in curly braces), strings are contracts/comments.
 
 |#
 
-#cs
+(provide info)
+(define info '
+
 (exn [exn_field_check
       (message "immutable string" "error message")
       (continuation-marks "mark set"
-			  "value returned by \\scmfirst{current-continuation-marks} immediately before the exception is raised")] 
+                          "value returned by \\scmfirst{current-continuation-marks} immediately before the exception is raised")] 
      -
      (fail [] "exceptions that represent errors"
-	   (contract [] "inappropriate run-time use of a function or syntactic form"
-		     (arity []
-			    "application with the wrong number of arguments")
-		     (divide-by-zero [] "divide by zero")
-		     (continuation [] "attempt to cross a continuation barrier")
-		     (variable [variable_field_check
-				(id "symbol" "the variable's identifier")]
-			       "unbound/not-yet-defined global or module variable"))
-	   (syntax [syntax_field_check
-		    (exprs "immutable list of syntax objects" "illegal expression(s)")
-		    {exn:source scheme_source_property |scheme_make_prim(extract_syntax_locations)|}]
-		   "syntax error, but not a \\scmfirst{read} error")
-	   (read [read_field_check
-		  (srclocs "immutable list of \\scmk{srcloc}s (see \\SecRef{linecol})" "source location(s) of error")
-		  {exn:source scheme_source_property  |scheme_make_prim(extract_read_locations)|}]
-		 "\\rawscm{read} parsing error"
-		 (eof [] "unexpected end-of-file")
-		 (non-char [] "unexpected non-character"))
-	   (filesystem [] "error manipulating a filesystem object"
-		       (exists [] "attempt to create a file that exists already")
-		       (version [] "version mismatch loading an extension"))
-	   (network [] "TCP and UDP errors")
-	   (out-of-memory [] "out of memory")
-	   (unsupported [] "unsupported feature")
-	   (user [] "for end users"))
-     
-     (break [break_field_check
-	     (continuation "escape continuation" "resumes from the break")]
-	    "asynchronous break signal"))
+           (contract [] "inappropriate run-time use of a function or syntactic form"
+                     (arity []
+                            "application with the wrong number of arguments")
+                     (divide-by-zero [] "divide by zero")
+                     (continuation [] "attempt to cross a continuation barrier")
+                     (variable [variable_field_check
+                                (id "symbol" "the variable's identifier")]
+                               "unbound/not-yet-defined global or module variable"))
+           (syntax [syntax_field_check
+                    (exprs "immutable list of syntax objects" "illegal expression(s)")
+                    {exn:source scheme_source_property |scheme_make_prim(extract_syntax_locations)|}]
+                   "syntax error, but not a \\scmfirst{read} error")
+           (read [read_field_check
+                  (srclocs "immutable list of \\scmk{srcloc}s (see \\SecRef{linecol})" "source location(s) of error")
+                  {exn:source scheme_source_property  |scheme_make_prim(extract_read_locations)|}]
+                 "\\rawscm{read} parsing error"
+                 (eof [] "unexpected end-of-file")
+                 (non-char [] "unexpected non-character"))
+           (filesystem [] "error manipulating a filesystem object"
+                       (exists [] "attempt to create a file that exists already")
+                       (version [] "version mismatch loading an extension"))
+           (network [] "TCP and UDP errors")
+           (out-of-memory [] "out of memory")
+           (unsupported [] "unsupported feature")
+           (user [] "for end users"))
 
+     (break [break_field_check
+             (continuation "escape continuation" "resumes from the break")]
+            "asynchronous break signal"))
+
+)
 
 #|
 Not an exception in the above sense:
      (special-comment [width "non-negative exact integer" "width of the special comment in port positions"]
-	"raised by a custom input port's special-reading procedure")
+        "raised by a custom input port's special-reading procedure")
 |#
-
diff --git a/src/mzscheme/src/makeexn b/src/mzscheme/src/makeexn
index 7f376a151c..f22b6d2df6 100755
--- a/src/mzscheme/src/makeexn
+++ b/src/mzscheme/src/makeexn
@@ -1,13 +1,21 @@
 #!/bin/sh
 #|
-if [ "$PLTHOME" = "" ] ; then PLTHOME=/usr/local/lib/plt ; export PLTHOME ; fi
-exec ${PLTHOME}/bin/mzscheme -gqr $0 "$@"
+if [ "$PLTHOME" = "" ]; then
+  exec mzscheme -um "$0" "$@"
+else
+  exec ${PLTHOME}/bin/mzscheme -um $0 "$@"
+fi
 |#
 
-(define doc? (and (= (vector-length argv) 1)
-		  (string=? (vector-ref argv 0) "doc")))
+#lang scheme
 
-(define l (read))
+(provide main)
+(define (main [arg #f])
+  (if (equal? arg "doc") (print-doc) (print-header)))
+
+(require "exnsrc.ss")
+
+(define l info)
 
 (define-struct ex (define string base doc args props guard parent parent-def numtotal depth mark))
 (define-struct fld (name type doc))
@@ -99,13 +107,7 @@ exec ${PLTHOME}/bin/mzscheme -gqr $0 "$@"
 				   (add1 depth)))
 	       (cdddr v)))))]))
 
-(define l (make-struct-list l
-			    #f
-			    #f
-			    ""
-			    0
-			    0))
-
+(set! l (make-struct-list l #f #f "" 0 0))
 
 (define (symbol-length s)
   (string-length (symbol->string s)))
@@ -116,192 +118,168 @@ exec ${PLTHOME}/bin/mzscheme -gqr $0 "$@"
    (regexp-replace* " " type "-")
    "or-#f"))
 
-(if doc?
-    (begin
-      (printf "% This file was generated by makeexn~n")
-      (display "\\begin{exntable}\n")
-      (for-each
-       (lambda (e)
-	 (let ([tab
-		(lambda (pre)
-		  (let loop ([d (ex-depth e)])
-		    (cond
-		     [(zero? d) ""]
-		     [(= d 1) (format "\\exn~ainset{}" pre)]
-		     [else
-		      (string-append (format "\\exn~atab{}" pre)
-				     (loop (sub1 d)))])))])
-	   (display (tab ""))
-	   (printf "\\exntype{~a}{~a}{~a}{~a} " 
-		   (ex-base e)
-		   (ex-string e)
-		   (case (ex-mark e)
-		     ((#f) "$\\bullet$")
-		     ((#\+) "$\\bullet$")
-		     ((#\*) "$\\bullet$"))
-		   (let ([make-var (lambda (f)
-				     (let ([type (let ([s (fld-type f)])
-						   (if (string=? s "value")
-						       "v"
-						       s))]
-					   [name (fld-name f)])
-				       (cond
-					[(eq? name 'value) "v"]
-					[(regexp-match "port" type) type]
-					[else (format "~a-~a" name (clean-help-desk-type type))])))])
-		     (let loop ([e e][s #f])
-		       (let* ([p (ex-parent e)]
-			      [s (if p (loop p s) s)])
-			 (let loop ([l (ex-args e)][s s])
-			   (cond
-			    [(null? l) s]
-			    [s (loop (cdr l) (string-append s " " (make-var (car l))))]
-			    [else (loop (cdr l) (make-var (car l)))]))))))
-	   
-	   (if (eq? (ex-doc e) '-)
-	       (printf "\\exnusenone{~a} " (tab ""))
-	       (printf "\\exnuse{~a}{~a}{~a} " (tab "") (ex-doc e)
-		       (- 6.3 (* 0.08 (symbol-length (ex-base e))) (* 0.25 (ex-depth e)))))
-	   
-	   (let ([args (ex-args e)]
-		 [print-one
-		  (lambda (f)
-		    (printf "\\exnfield{~a}{~a}{~s}{~a}{~a} " 
-			    (fld-name f) (ex-string e)
-			    (- 5.4 (* 0.08 (symbol-length (fld-name f))) (* 0.25 (ex-depth e))) (fld-doc f) 
-			    (fld-type f)))])
-	     (unless (null? args)
-		     (printf "\\exnbeginfields{~a} " (tab ""))
-		     (print-one (car args))
-		     (for-each (lambda (f)
-				 (printf "\\exnnextfield{~a}" (tab ""))
-				 (print-one f))
-			       (cdr args))
-		     (printf "\\exnendfields{~a}" (tab ""))))
-	   (printf "\\exnendline{}")
-	   (display (tab "close"))
-	   (newline)))
-       l)
-      (display "\\end{exntable}\n"))
-    (begin
-      (printf "/* This file was generated by makeexn */~n")
+(define (print-doc)
+  (printf "% This file was generated by makeexn~n")
+  (display "\\begin{exntable}\n")
+  (for-each
+   (lambda (e)
+     (let ([tab
+            (lambda (pre)
+              (let loop ([d (ex-depth e)])
+                (cond
+                  [(zero? d) ""]
+                  [(= d 1) (format "\\exn~ainset{}" pre)]
+                  [else
+                   (string-append (format "\\exn~atab{}" pre)
+                                  (loop (sub1 d)))])))])
+       (display (tab ""))
+       (printf "\\exntype{~a}{~a}{~a}{~a} " 
+               (ex-base e)
+               (ex-string e)
+               (case (ex-mark e)
+                 ((#f) "$\\bullet$")
+                 ((#\+) "$\\bullet$")
+                 ((#\*) "$\\bullet$"))
+               (let ([make-var (lambda (f)
+                                 (let ([type (let ([s (fld-type f)])
+                                               (if (string=? s "value")
+                                                 "v"
+                                                 s))]
+                                       [name (fld-name f)])
+                                   (cond
+                                     [(eq? name 'value) "v"]
+                                     [(regexp-match "port" type) type]
+                                     [else (format "~a-~a" name (clean-help-desk-type type))])))])
+                 (let loop ([e e][s #f])
+                   (let* ([p (ex-parent e)]
+                          [s (if p (loop p s) s)])
+                     (let loop ([l (ex-args e)][s s])
+                       (cond
+                         [(null? l) s]
+                         [s (loop (cdr l) (string-append s " " (make-var (car l))))]
+                         [else (loop (cdr l) (make-var (car l)))]))))))
+       
+       (if (eq? (ex-doc e) '-)
+         (printf "\\exnusenone{~a} " (tab ""))
+         (printf "\\exnuse{~a}{~a}{~a} " (tab "") (ex-doc e)
+                 (- 6.3 (* 0.08 (symbol-length (ex-base e))) (* 0.25 (ex-depth e)))))
+       
+       (let ([args (ex-args e)]
+             [print-one
+              (lambda (f)
+                (printf "\\exnfield{~a}{~a}{~s}{~a}{~a} " 
+                        (fld-name f) (ex-string e)
+                        (- 5.4 (* 0.08 (symbol-length (fld-name f))) (* 0.25 (ex-depth e))) (fld-doc f) 
+                        (fld-type f)))])
+         (unless (null? args)
+           (printf "\\exnbeginfields{~a} " (tab ""))
+           (print-one (car args))
+           (for-each (lambda (f)
+                       (printf "\\exnnextfield{~a}" (tab ""))
+                       (print-one f))
+                     (cdr args))
+           (printf "\\exnendfields{~a}" (tab ""))))
+       (printf "\\exnendline{}")
+       (display (tab "close"))
+       (newline)))
+   l)
+  (display "\\end{exntable}\n"))
 
-      (printf "#ifndef _MZEXN_DEFINES~n")
-      (printf "#define _MZEXN_DEFINES~n~n")
-      (printf "enum {~n")
-      (for-each
-       (lambda (e)
-	 (printf "  ~a,~n" (ex-define e)))
-       l)
-      (printf "  MZEXN_OTHER~n};~n~n")
-      (printf "#endif~n~n")
-      
-      
-      (printf "#ifdef _MZEXN_TABLE~n~n")
-      (printf "#define MZEXN_MAXARGS ~a~n~n" max-exn-args)
-	
-      (printf "#ifdef GLOBAL_EXN_ARRAY~n")
-
-      (printf "static exn_rec exn_table[] = {~n")
-      (let loop ([ll l])
-	(let ([e (car ll)])
-	  
-	  (printf "  { ~a, NULL, NULL, 0, NULL, ~a }" 
-		  (ex-numtotal e)
-		  (if (ex-parent e)
-		      (let loop ([pos 0][ll l])
-			(if (eq? (car ll) (ex-parent e))
-			    pos
-			    (loop (add1 pos) (cdr ll))))
-		      -1))
-	  
-	  (unless (null? (cdr ll))
-		  (printf ",~n")
-		  (loop (cdr ll)))))
-      (printf "~n};~n")
-
-      (printf "#else~n")
-      (printf "static exn_rec *exn_table;~n")      
-      (printf "#endif~n")
-
-      (printf "~n#endif~n~n")
-
-      (printf "#ifdef _MZEXN_PRESETUP~n~n")
-      (printf "#ifndef GLOBAL_EXN_ARRAY~n")
-      (printf "  exn_table = (exn_rec *)scheme_malloc(sizeof(exn_rec) * MZEXN_OTHER);~n")
-      (let loop ([l l])
-	(let ([e (car l)])
-	  
-	  (printf "  exn_table[~a].args = ~a;~n"
-		  (ex-define e)
-		  (ex-numtotal e))
-	  (unless (null? (cdr l))
-		  (loop (cdr l)))))
-      (printf "#endif~n")
-      (printf "~n#endif~n~n")      
-      
-      (printf "#ifdef _MZEXN_DECL_FIELDS~n~n")
-      
-      (for-each
-       (lambda (e)
-	 (let ([l (ex-args e)])
-	   (unless (null? l)
-		   (printf "static const char *~a_FIELDS[~s] = { \"~a\"" 
-			   (ex-define e)
-			   (length l) 
-			   (fld-name (car l)))
-		   (for-each
-		    (lambda (field)
-		      (printf ", \"~a\"" (fld-name field)))
-		    (cdr l))
-		   (printf " };~n"))))
-       l)
-
-      (printf "~n#endif~n~n")
-      
-      (printf "#ifdef _MZEXN_DECL_PROPS~n~n")
-      
-      (for-each
-       (lambda (e)
-	 (let ([l (ex-props e)])
-	   (unless (null? l)
-	     (printf "#define ~a_PROPS " (ex-define e))
-	     (let loop ([l l])
-	       (if (null? l)
-		   (printf "scheme_null")
-		   (begin
-		     (printf "scheme_make_pair(")
-		     (printf "scheme_make_pair(~a, ~a), "
-			     (prop-c-name (car l)) 
-			     (prop-value (car l)))
-		     (loop (cdr l))
-		     (printf ")"))))
-	     (printf "~n"))))
-       l)
-
-      (printf "~n#endif~n~n")
-      
-      (printf "#ifdef _MZEXN_SETUP~n~n")
-      
-      (for-each
-       (lambda (e)
-	 (printf "  SETUP_STRUCT(~a, ~a, ~s, ~a, ~a, ~a, ~a)~n"
-		 (ex-define e)
-		 (let ([p (ex-parent-def e)])
-		   (if p
-		       (format "EXN_PARENT(~a)" p)
-		       #cs'NULL))
-		 (ex-string e)
-		 (length (ex-args e))
-		 (if (null? (ex-args e))
-		     "NULL"
-		     (format "~a_FIELDS" (ex-define e)))
-		 (if (null? (ex-props e))
-		     "scheme_null"
-		     (format "~a_PROPS" (ex-define e)))
-		 (if (ex-guard e)
-		     (format "scheme_make_prim(~a)" (ex-guard e))
-		     "NULL")))
-       l)
-
-      (printf "~n#endif~n")))
+(define (print-header)
+  (printf "/* This file was generated by makeexn */~n")
+  (printf "#ifndef _MZEXN_DEFINES~n")
+  (printf "#define _MZEXN_DEFINES~n~n")
+  (printf "enum {~n")
+  (for-each (lambda (e) (printf "  ~a,~n" (ex-define e)))
+            l)
+  (printf "  MZEXN_OTHER~n};~n~n")
+  (printf "#endif~n~n")
+  (printf "#ifdef _MZEXN_TABLE~n~n")
+  (printf "#define MZEXN_MAXARGS ~a~n~n" max-exn-args)
+  (printf "#ifdef GLOBAL_EXN_ARRAY~n")
+  (printf "static exn_rec exn_table[] = {~n")
+  (let loop ([ll l])
+    (let ([e (car ll)])
+      (printf "  { ~a, NULL, NULL, 0, NULL, ~a }" 
+              (ex-numtotal e)
+              (if (ex-parent e)
+                (let loop ([pos 0][ll l])
+                  (if (eq? (car ll) (ex-parent e))
+                    pos
+                    (loop (add1 pos) (cdr ll))))
+                -1))
+      (unless (null? (cdr ll))
+        (printf ",~n")
+        (loop (cdr ll)))))
+  (printf "~n};~n")
+  (printf "#else~n")
+  (printf "static exn_rec *exn_table;~n")      
+  (printf "#endif~n")
+  (printf "~n#endif~n~n")
+  (printf "#ifdef _MZEXN_PRESETUP~n~n")
+  (printf "#ifndef GLOBAL_EXN_ARRAY~n")
+  (printf "  exn_table = (exn_rec *)scheme_malloc(sizeof(exn_rec) * MZEXN_OTHER);~n")
+  (let loop ([l l])
+    (let ([e (car l)])
+      (printf "  exn_table[~a].args = ~a;~n"
+              (ex-define e)
+              (ex-numtotal e))
+      (unless (null? (cdr l))
+        (loop (cdr l)))))
+  (printf "#endif~n")
+  (printf "~n#endif~n~n")
+  (printf "#ifdef _MZEXN_DECL_FIELDS~n~n")
+  (for-each
+   (lambda (e)
+     (let ([l (ex-args e)])
+       (unless (null? l)
+         (printf "static const char *~a_FIELDS[~s] = { \"~a\"" 
+                 (ex-define e) (length l) (fld-name (car l)))
+         (for-each
+          (lambda (field)
+            (printf ", \"~a\"" (fld-name field)))
+          (cdr l))
+         (printf " };~n"))))
+   l)
+  (printf "~n#endif~n~n")
+  (printf "#ifdef _MZEXN_DECL_PROPS~n~n")
+  (for-each
+   (lambda (e)
+     (let ([l (ex-props e)])
+       (unless (null? l)
+         (printf "#define ~a_PROPS " (ex-define e))
+         (let loop ([l l])
+           (if (null? l)
+             (printf "scheme_null")
+             (begin
+               (printf "scheme_make_pair(")
+               (printf "scheme_make_pair(~a, ~a), "
+                       (prop-c-name (car l)) 
+                       (prop-value (car l)))
+               (loop (cdr l))
+               (printf ")"))))
+         (printf "~n"))))
+   l)
+  (printf "~n#endif~n~n")
+  (printf "#ifdef _MZEXN_SETUP~n~n")
+  (for-each
+   (lambda (e)
+     (printf "  SETUP_STRUCT(~a, ~a, ~s, ~a, ~a, ~a, ~a)~n"
+             (ex-define e)
+             (let ([p (ex-parent-def e)])
+               (if p
+                 (format "EXN_PARENT(~a)" p)
+                 #cs'NULL))
+             (ex-string e)
+             (length (ex-args e))
+             (if (null? (ex-args e))
+               "NULL"
+               (format "~a_FIELDS" (ex-define e)))
+             (if (null? (ex-props e))
+               "scheme_null"
+               (format "~a_PROPS" (ex-define e)))
+             (if (ex-guard e)
+               (format "scheme_make_prim(~a)" (ex-guard e))
+               "NULL")))
+   l)
+  (printf "~n#endif~n"))