diff --git a/collects/compiler/compiler-unit.rkt b/collects/compiler/compiler-unit.rkt
index 3912d73b58..1c1d67fc03 100644
--- a/collects/compiler/compiler-unit.rkt
+++ b/collects/compiler/compiler-unit.rkt
@@ -201,9 +201,11 @@
   (define (compile-directory dir info 
                              #:verbose [verbose? #t] 
                              #:skip-path [orig-skip-path #f]
-                             #:skip-doc-sources? [skip-docs? #f])
+                             #:skip-doc-sources? [skip-docs? #f]
+                             #:managed-compile-zo [managed-compile-zo
+                                                   (make-caching-managed-compile-zo)])
     (define (worker prev sses)
-      (for-each (make-caching-managed-compile-zo) sses))
+      (for-each managed-compile-zo sses))
     (compile-directory-visitor dir info worker 
                              #:verbose verbose?
                              #:skip-path orig-skip-path
@@ -212,21 +214,27 @@
   (define (get-compile-directory-srcs dir info 
                              #:verbose [verbose? #t] 
                              #:skip-path [orig-skip-path #f]
-                             #:skip-doc-sources? [skip-docs? #f])
+                             #:skip-doc-sources? [skip-docs? #f]
+                             #:managed-compile-zo [managed-compile-zo
+                                                   (make-caching-managed-compile-zo)])
     (compile-directory-visitor dir info append
                              #:verbose verbose?
                              #:skip-path orig-skip-path
-                             #:skip-doc-sources? skip-docs?))
+                             #:skip-doc-sources? skip-docs?
+                             #:managed-compile-zo managed-compile-zo))
 
   (define (compile-collection-zos collection 
                                   #:skip-path [skip-path #f]
                                   #:skip-doc-sources? [skip-docs? #f]
+                                  #:managed-compile-zo [managed-compile-zo
+                                                        (make-caching-managed-compile-zo)]
                                   . cp)
     (compile-directory (apply collection-path collection cp)
                        (c-get-info (cons collection cp))
                        #:verbose #f
                        #:skip-path skip-path
-                       #:skip-doc-sources? skip-docs?))
+                       #:skip-doc-sources? skip-docs?
+                       #:managed-compile-zo managed-compile-zo))
 
   (define compile-directory-zos compile-directory)
   (define compile-directory-srcs get-compile-directory-srcs)
diff --git a/collects/scribblings/raco/api.scrbl b/collects/scribblings/raco/api.scrbl
index 064f136f98..f4ff5cc836 100644
--- a/collects/scribblings/raco/api.scrbl
+++ b/collects/scribblings/raco/api.scrbl
@@ -9,6 +9,7 @@
                      compiler/option
                      compiler/option-unit
                      compiler/comp-unit
+                     compiler/cm
                      dynext/compile-sig
                      dynext/link-sig
                      dynext/file-sig
@@ -70,15 +71,21 @@ file is reported through the current output port.}
 
 @defproc[(compile-collection-zos [collection string?] ...+
                                  [#:skip-path skip-path (or/c path-string? #f) #f]
-                                 [#:skip-doc-sources? skip-docs? any/c #f])
+                                 [#:skip-doc-sources? skip-docs? any/c #f]
+                                 [#:managed-compile-zo managed-compile-zo 
+                                                       (path-string? . -> . void?)
+                                                       (make-caching-managed-compile-zo)])
          void?]{
 
-Compiles the specified collection's files to @filepath{.zo} files.
+Compiles the specified collection's files to @filepath{.zo} files
+by using @racket[managed-compile-zo] on each source file.
 The @filepath{.zo} files are placed into the collection's
-@filepath{compiled} directory. By default, all files with the
+@filepath{compiled} directory.
+
+By default, all files with the
 extension @filepath{.rkt}, @filepath{.ss}, or @filepath{.scm} in a collection are
 compiled, as are all such files within subdirectories, execept that
-any file or directory whose path starts with @scheme[racket-path] is
+any file or directory whose path starts with @scheme[skip-path] is
 skipped. (``Starts with'' means that the simplified path @scheme[_p]'s
 byte-string form after @scheme[(simplify-path _p #f)]starts with the
 byte-string form of @scheme[(simplify-path skip-path #f)].)
@@ -118,17 +125,17 @@ collection.  The following fields are used:
        unless the provided @scheme[skip-docs?] argument is a true
        value.}
 
-]
-
-The compilation process for an individual file is driven by
-@scheme[managed-compile-zo] from @schememodname[compiler/cm].}
+]}
 
 
 @defproc[(compile-directory-zos [path path-string?]
                                 [info ()]
                                 [#:verbose verbose? any/c #f]
                                 [#:skip-path skip-path (or/c path-string? #f) #f]
-                                [#:skip-doc-sources? skip-docs? any/c #f])
+                                [#:skip-doc-sources? skip-docs? any/c #f]
+                                [#:managed-compile-zo managed-compile-zo 
+                                                      (path-string? . -> . void?)
+                                                      (make-caching-managed-compile-zo)])
          void?]{
 
 Like @scheme[compile-collection-zos], but compiles the given directory
diff --git a/collects/setup/setup-unit.rkt b/collects/setup/setup-unit.rkt
index 988d567280..e8fef2f8d5 100644
--- a/collects/setup/setup-unit.rkt
+++ b/collects/setup/setup-unit.rkt
@@ -124,7 +124,6 @@
         (when (not (zero? (string-length err))) (eprintf "STDERR:\n~a=====\n" err)))))
 
   (define (done)
-    (setup-printf #f "done")
     (unless (null? errors)
       (setup-printf #f "")
       (show-errors (current-error-port))
@@ -639,6 +638,11 @@
                               (thunk)))])
             (thunk))))))
 
+  ;; We keep timestamp information for all files that we try to compile.
+  ;; That's O(N) for an installation of size N, but the constant is small,
+  ;; and it makes a do-nothing setup complete much faster.
+  (define caching-managed-compile-zo (make-caching-managed-compile-zo))
+
   (define (compile-cc cc gcs)
     (parameterize ([current-namespace (make-base-empty-namespace)])
       (begin-record-error cc "making"
@@ -651,6 +655,7 @@
                 [info (cc-info cc)])
             (clean-cc dir info)
             (compile-directory-zos dir info 
+                                   #:managed-compile-zo caching-managed-compile-zo
                                    #:skip-path (and (avoid-main-installation) (find-collects-dir))
                                    #:skip-doc-sources? (not (make-docs)))))))
     (match gcs