diff --git a/INSTALL.txt b/INSTALL.txt
index 5f928efdf3..be2c7618eb 100644
--- a/INSTALL.txt
+++ b/INSTALL.txt
@@ -178,13 +178,14 @@ More Instructions: Building Racket-on-Chez
 ==========================================
 
 The `make cs` target (or `make cs-as-is` for a rebuild, or `nmake
-win32-cs` on Windows with Visual Studio) builds an experimental
-variant of Racket that runs on Chez Scheme. By default, the
-executables for the Racket-on-Chez variant all have a "cs" or "CS"
-suffix, so they coexist with a traditional Racket build. You can
-remove the "cs" suffix by providing `RACKETCS_SUFFIX=""` to `make`.
-(One day, if the experiment goes well, the default for
-`RACKETCS_SUFFIX with change from "cs" to "".)
+win32-cs` on Windows with Visual Studio) builds a variant of Racket
+that runs on Chez Scheme. By default, the executables for the
+Racket-on-Chez variant all have a "cs" or "CS" suffix, and they
+coexist with a traditional Racket build by keeping compiled files in a
+machine-specific subdirectory of the "compiled" directory. You can
+remove the "cs" suffix and the subdirectory in "compiled" by providing
+`RACKETCS_SUFFIX=""` to `make`. (One day, if all goes well, the
+default for `RACKETCS_SUFFIX` will change from "cs" to "".)
 
 Building Racket-on-Chez requires an existing Racket and Chez Scheme.
 If you use `make cs` with no further arguments, then the build process
diff --git a/Makefile b/Makefile
index 0ae4a31a12..37592b913b 100644
--- a/Makefile
+++ b/Makefile
@@ -282,9 +282,12 @@ cs-base:
 cs-as-is:
 	$(MAKE) cs CS_SETUP_TARGET=in-place-setup
 
+CS_CONFIG_TARGET = no-cfg-cs
+RACKET_GIVEN_ARGS = RACKET="$(RACKET_BUILT_FOR_CS)" CS_CONFIG_TARGET=run-cfg-cs SETUP_BOOT_MODE=--boot
+
 cs-after-racket:
 	if [ "$(RACKET)" = "" ] ; \
-         then $(MAKE) cs-after-racket-with-racket RACKET="$(RACKET_BUILT_FOR_CS)" SETUP_BOOT_MODE=--boot ; \
+         then $(MAKE) cs-after-racket-with-racket $(RACKET_GIVEN_ARGS) ; \
          else $(MAKE) cs-after-racket-with-racket RACKET="$(RACKET)" ; fi
 
 RACKETCS_SUFFIX_CONFIG = MORE_CONFIGURE_ARGS="$(MORE_CONFIGURE_ARGS) --enable-csdefault" PLAIN_RACKET="$(PLAIN_RACKET)3m"
@@ -296,7 +299,7 @@ racket-then-cs:
 
 racket-configured-then-cs:
 	$(MAKE) plain-base BASE_INSTALL_TARGET=nothing-after-base
-	$(MAKE) cs-after-racket-with-racket RACKET="$(RACKET_BUILT_FOR_CS)" SETUP_BOOT_MODE=--boot
+	$(MAKE) cs-after-racket-with-racket $(RACKET_GIVEN_ARGS)
 
 cs-only:
 	$(MAKE) racket/src/build/Makefile SRC_MAKEFILE_CONFIG=cfg-cs
@@ -327,9 +330,16 @@ cs-after-racket-with-abs-paths:
 nothing-after-base:
 	echo base done
 
-racket/src/build/cs/Makefile: racket/src/cs/c/configure racket/src/cs/c/Makefile.in
+racket/src/build/cs/Makefile: racket/src/cs/c/configure racket/src/cs/c/Makefile.in racket/src/cfg-cs
 	mkdir -p cd racket/src/build/cs
-	cd racket/src/build/cs; ../../cs/c/configure
+	cd racket/src/build/cs; ../../cs/c/configure $(CONFIGURE_ARGS_qq) $(MORE_CONFIGURE_ARGS)
+	$(MAKE) $(CS_CONFIG_TARGET)
+
+run-cfg-cs:
+	cd racket/src/build; ../../cs/cfg-cs $(CONFIGURE_ARGS_qq) $(MORE_CONFIGURE_ARGS)
+
+no-cfg-cs:
+	echo done
 
 scheme-src:
 	$(MAKE) racket/src/build/ChezScheme
diff --git a/racket/src/cs/Makefile b/racket/src/cs/Makefile
index 2cf11a1dfd..84bc6f6a29 100644
--- a/racket/src/cs/Makefile
+++ b/racket/src/cs/Makefile
@@ -19,7 +19,7 @@ RUMBLE_UNSAFE_COMP = --unsafe
 COMPILE_FILE = $(SCHEME) --script compile-file.ss $(UNSAFE_COMP) $(COMPRESS_COMP) $(DEBUG_COMP) --dest "$(BUILDDIR)"
 COMPILE_FILE_DEPS = compile-file.ss include.ss place-register.ss 
 
-RACKET_SETUP_ARGS = ../../bin/racket ../collects ../etc 0 false
+RACKET_SETUP_ARGS = ../../bin/racket ../collects ../etc 0 true false
 
 PRIMITIVES_TABLES = primitive/kernel.ss primitive/unsafe.ss primitive/flfxnum.ss \
                     primitive/paramz.ss primitive/extfl.ss primitive/network.ss \
diff --git a/racket/src/cs/c/Makefile.in b/racket/src/cs/c/Makefile.in
index 9c241e3a1c..792b78dc5e 100644
--- a/racket/src/cs/c/Makefile.in
+++ b/racket/src/cs/c/Makefile.in
@@ -131,10 +131,10 @@ racket.boot: racket.so
 EMBED_DEPS = $(srcdir)/embed-boot.rkt
 
 racketcs@NOT_OSX@: raw_racketcs racket.boot $(EMBED_DEPS)
-	$(RACKET) $(srcdir)/embed-boot.rkt @COMPRESS_COMP@ raw_racketcs racketcs $(SCHEME_INC) racket.boot
+	$(BOOTSTRAP_RACKET) $(srcdir)/embed-boot.rkt @COMPRESS_COMP@ raw_racketcs racketcs $(SCHEME_INC) racket.boot
 
 gracketcs@NOT_OSX@: raw_gracketcs racket.boot $(EMBED_DEPS)
-	$(RACKET) $(srcdir)/embed-boot.rkt @COMPRESS_COMP@ raw_gracketcs gracketcs $(SCHEME_INC) racket.boot
+	$(BOOTSTRAP_RACKET) $(srcdir)/embed-boot.rkt @COMPRESS_COMP@ raw_gracketcs gracketcs $(SCHEME_INC) racket.boot
 
 BOOT_OBJS = boot.o $(SCHEME_INC)/kernel.o rktio/librktio.a
 
@@ -165,7 +165,7 @@ $(GRACKET_BIN): grmain.o $(RKTFW) $(GRAPPSKEL)
 	/usr/bin/install_name_tool -change "Racket.framework/Versions/$(FWVERSION)_CS/Racket" "@executable_path/../../../Racket.framework/Versions/$(FWVERSION)_CS/Racket" $(GRACKET_BIN)
 
 $(GRAPPSKEL): $(srcdir)/../../mac/osx_appl.rkt  $(srcdir)/../../racket/src/schvers.h $(srcdir)/../../mac/icon/GRacket.icns
-	env $(RACKET) $(srcdir)/../../mac/osx_appl.rkt $(srcdir)/../.. "CS"
+	$(BOOTSTRAP_RACKET) $(srcdir)/../../mac/osx_appl.rkt $(srcdir)/../.. "CS"
 
 BOOT_FILES = $(SCHEME_INC)/petite.boot $(SCHEME_INC)/scheme.boot racket.boot
 FW_BOOT_DEST = Racket.framework/Versions/$(FWVERSION)_CS/boot
@@ -178,7 +178,7 @@ $(RKTFW): $(BOOT_OBJS) $(BOOT_FILES)
 	mkdir -p Racket.framework/Versions/$(FWVERSION)_CS/boot
 	cp $(SCHEME_INC)/petite.boot $(SCHEME_INC)/scheme.boot $(FW_BOOT_DEST)
 	cp racket.boot $(FW_BOOT_DEST)
-	$(RACKET) $(srcdir)/adjust-compress.rkt @COMPRESS_COMP@ $(FW_BOOT_DEST)/petite.boot $(FW_BOOT_DEST)/scheme.boot $(FW_BOOT_DEST)/racket.boot
+	$(BOOTSTRAP_RACKET) $(srcdir)/adjust-compress.rkt @COMPRESS_COMP@ $(FW_BOOT_DEST)/petite.boot $(FW_BOOT_DEST)/scheme.boot $(FW_BOOT_DEST)/racket.boot
 
 # ----------------------------------------
 # Common
@@ -186,11 +186,12 @@ $(RKTFW): $(BOOT_OBJS) $(BOOT_FILES)
 DEF_COLLECTS_DIR = -DINITIAL_COLLECTS_DIRECTORY='"'"`cd $(srcdir)/../../../collects; pwd`"'"'
 DEF_CONFIG_DIR = -DINITIAL_CONFIG_DIRECTORY='"'"`cd $(srcdir)/../../..; pwd`/etc"'"'
 DEF_C_DIRS = $(DEF_COLLECTS_DIR) $(DEF_CONFIG_DIR)
+COMP_SUBDIR = -DCS_COMPILED_SUBDIR=@CS_COMPILED_SUBDIR@
 
 MAIN_DEPS = $(srcdir)/main.c $(srcdir)/boot.h $(srcdir)/../../start/config.inc
 
 main.o: $(MAIN_DEPS)
-	$(CC) $(CFLAGS) $(DEF_C_DIRS) -c -o main.o $(srcdir)/main.c
+	$(CC) $(CFLAGS) $(DEF_C_DIRS) $(COMP_SUBDIR) -c -o main.o $(srcdir)/main.c
 
 grmain.o: $(srcdir)/grmain.c $(MAIN_DEPS) $(srcdir)/../../start/gui_filter.inc
 	$(CC) $(CFLAGS) $(DEF_C_DIRS) -c -o grmain.o $(srcdir)/grmain.c
@@ -255,6 +256,6 @@ macos-install-gracket:
 	/usr/bin/install_name_tool -change "@executable_path/Racket.framework/Versions/$(FWVERSION)_CS/Racket" "@FRAMEWORK_PREFIX@Racket.framework/Versions/$(FWVERSION)_CS/Racket" $(DESTDIR)"$(bindir)/racket$(CS_INSTALLED)"
 	rm -rf $(DESTDIR)"$(libpltdir)/GRacket$(CS_GR_INSTALLED).app"
 	$(ICP) -r "GRacketCS.app" $(DESTDIR)"$(libpltdir)/GRacket$(CS_GR_INSTALLED).app"
-	$(RACKET) "$(srcdir)/../../mac/rename-app.rkt" $(DESTDIR)"$(libpltdir)/GRacket$(CS_GR_INSTALLED).app" "GRacketCS" "GRacket$(CS_GR_INSTALLED)" no-up
+	$(BOOTSTRAP_RACKET) "$(srcdir)/../../mac/rename-app.rkt" $(DESTDIR)"$(libpltdir)/GRacket$(CS_GR_INSTALLED).app" "GRacketCS" "GRacket$(CS_GR_INSTALLED)" no-up
 	/usr/bin/install_name_tool -change "@executable_path/../../../../racket/Racket.framework/Versions/$(FWVERSION)_CS/Racket" "@FRAMEWORK_PREFIX@Racket.framework/Versions/$(FWVERSION)_CS/Racket" $(DESTDIR)"$(libpltdir)/GRacket$(CS_GR_INSTALLED).app/Contents/MacOS/GRacket$(CS_GR_INSTALLED)"
-	$(RACKET) "$(srcdir)/../../racket/collects-path.rkt" $(DESTDIR)"$(libpltdir)/GRacket$(CS_GR_INSTALLED).app/Contents/MacOS/GRacket$(CS_GR_INSTALLED)" ../../../../collects ../../../../etc
+	$(RACKET) -cu "$(srcdir)/../../racket/collects-path.rkt" $(DESTDIR)"$(libpltdir)/GRacket$(CS_GR_INSTALLED).app/Contents/MacOS/GRacket$(CS_GR_INSTALLED)" ../../../../collects ../../../../etc
diff --git a/racket/src/cs/c/boot.c b/racket/src/cs/c/boot.c
index 67c2d3a15d..16f73fe560 100644
--- a/racket/src/cs/c/boot.c
+++ b/racket/src/cs/c/boot.c
@@ -81,7 +81,7 @@ static void init_foreign()
 void racket_boot(int argc, char **argv, char *self, long segment_offset,
                  char *coldir, char *configdir,
                  int pos1, int pos2, int pos3,
-                 int is_gui)
+                 int cs_compiled_subdir, int is_gui)
 /* exe argument already stripped from argv */
 {
 #if !defined(RACKET_USE_FRAMEWORK) || !defined(RACKET_AS_BOOT)
@@ -133,6 +133,7 @@ void racket_boot(int argc, char **argv, char *self, long segment_offset,
       l = Scons(Sbytevector(argv[i]), l);
     }
     l = Scons(Sbytevector(is_gui ? "true" : "false"), l);
+    l = Scons(Sbytevector(cs_compiled_subdir ? "true" : "false"), l);
     sprintf(segment_offset_s, "%ld", segment_offset);
     l = Scons(Sbytevector(segment_offset_s), l);
     l = Scons(Sbytevector(configdir), l);
diff --git a/racket/src/cs/c/boot.h b/racket/src/cs/c/boot.h
index ea2278663f..d8d95bd21f 100644
--- a/racket/src/cs/c/boot.h
+++ b/racket/src/cs/c/boot.h
@@ -1,4 +1,4 @@
 void racket_boot(int argc, char **argv, char *self, long segment_offset,
                  char *coldir, char *configdir,
                  int pos1, int pos2, int pos3,
-                 int is_gui);
+                 int cs_compiled_subdir, int is_gui);
diff --git a/racket/src/cs/c/configure b/racket/src/cs/c/configure
index d6ac12f6e3..342ebc495e 100755
--- a/racket/src/cs/c/configure
+++ b/racket/src/cs/c/configure
@@ -622,6 +622,7 @@ ac_includes_default="\
 
 ac_subst_vars='LTLIBOBJS
 LIBOBJS
+CS_COMPILED_SUBDIR
 CS_INSTALLED
 FRAMEWORK_PREFIX
 FRAMEWORK_INSTALL_DIR
@@ -2538,6 +2539,12 @@ if test "${enable_csdefault}" = "yes" ; then
   CS_INSTALLED=""
 fi
 
+CS_COMPILED_SUBDIR=1
+if test "${enable_csdefault}" = "yes" ; then
+  CS_COMPILED_SUBDIR=0
+fi
+
+
 ############## Install targets ################
 
 PREFIX_PATH_RELATIVE=/../..
@@ -4441,6 +4448,7 @@ CPPFLAGS="$CPPFLAGS $PREFLAGS"
 
 
 
+
 
 
 makefiles="Makefile"
diff --git a/racket/src/cs/c/configure.ac b/racket/src/cs/c/configure.ac
index 5dd68ca0d2..ee50617a74 100644
--- a/racket/src/cs/c/configure.ac
+++ b/racket/src/cs/c/configure.ac
@@ -79,6 +79,12 @@ if test "${enable_csdefault}" = "yes" ; then
   CS_INSTALLED=""
 fi
 
+CS_COMPILED_SUBDIR=1
+if test "${enable_csdefault}" = "yes" ; then
+  CS_COMPILED_SUBDIR=0
+fi
+
+
 ############## Install targets ################
 
 PREFIX_PATH_RELATIVE=/../..
@@ -419,6 +425,7 @@ AC_SUBST(SCHEME_CONFIG_ARGS)
 AC_SUBST(FRAMEWORK_INSTALL_DIR)
 AC_SUBST(FRAMEWORK_PREFIX)
 AC_SUBST(CS_INSTALLED)
+AC_SUBST(CS_COMPILED_SUBDIR)
 
 makefiles="Makefile"
 
diff --git a/racket/src/cs/c/main.c b/racket/src/cs/c/main.c
index 015b7ea192..7a1ae3f135 100644
--- a/racket/src/cs/c/main.c
+++ b/racket/src/cs/c/main.c
@@ -20,6 +20,10 @@ static int scheme_utf8_encode(unsigned int *path, int zero_offset, int len,
 # define RACKET_IS_GUI 0
 #endif
 
+#ifndef CS_COMPILED_SUBDIR
+# define CS_COMPILED_SUBDIR 1
+#endif
+
 #define XFORM_SKIP_PROC /* empty */
 
 #include "../../start/config.inc"
@@ -128,7 +132,7 @@ int main(int argc, char **argv)
   racket_boot(argc, argv, self, segment_offset,
               extract_coldir(), extract_configdir(),
               pos1, pos2, pos3,
-              RACKET_IS_GUI);
+              CS_COMPILED_SUBDIR, RACKET_IS_GUI);
   
   return 0;
 }
diff --git a/racket/src/cs/main.sps b/racket/src/cs/main.sps
index 09b695a7c3..ead87c62b3 100644
--- a/racket/src/cs/main.sps
+++ b/racket/src/cs/main.sps
@@ -56,31 +56,35 @@
           the-command-line-arguments/maybe-bytes))
 
    (seq
-    (unless (>= (length the-command-line-arguments) 5)
-      (error 'racket "expected `self`, `collects`, and `libs` paths plus `segment-offset` and `is-gui?` to start"))
+    (unless (>= (length the-command-line-arguments) 6)
+      (error 'racket "expected `self`, `collects`, and `libs` paths plus `segment-offset`, `cs-compiled-subdir?`, and `is-gui?` to start"))
     (set-exec-file! (path->complete-path (car the-command-line-arguments))))
    (define init-collects-dir (let ([s (cadr the-command-line-arguments)])
                                (if (equal? s "") 'disable (string->path s))))
    (define init-config-dir (string->path (or (getenv "PLTCONFIGDIR")
                                              (caddr the-command-line-arguments))))
    (define segment-offset (#%string->number (list-ref the-command-line-arguments 3)))
-   (define gracket? (string=? "true" (list-ref the-command-line-arguments 4)))
+   (define cs-compiled-subdir? (string=? "true" (list-ref the-command-line-arguments 4)))
+   (define gracket? (string=? "true" (list-ref the-command-line-arguments 5)))
 
    (seq
     (when (foreign-entry? "racket_exit")
       (#%exit-handler (foreign-procedure "racket_exit" (int) void))))
 
    (define compiled-file-paths
-     (list (string->path (string-append "compiled/"
-                                        (cond
-                                         [(getenv "PLT_ZO_PATH")
-                                          => (lambda (s)
-                                               (unless (and (not (equal? s ""))
-                                                            (relative-path? s))
-                                                 (error 'racket "PLT_ZO_PATH environment variable is not a valid path"))
-                                               s)]
-                                         [platform-independent-zo-mode? "cs"]
-                                         [else (symbol->string (machine-type))])))))
+     (list (string->path (cond
+                          [cs-compiled-subdir?
+                           (string-append "compiled/"
+                                          (cond
+                                           [(getenv "PLT_ZO_PATH")
+                                            => (lambda (s)
+                                                 (unless (and (not (equal? s ""))
+                                                              (relative-path? s))
+                                                   (error 'racket "PLT_ZO_PATH environment variable is not a valid path"))
+                                                 s)]
+                                           [platform-independent-zo-mode? "cs"]
+                                           [else (symbol->string (machine-type))]))]
+                          [else "compiled"]))))
    (define user-specific-search-paths? #t)
    (define load-on-demand? #t)
 
@@ -216,7 +220,7 @@
    (define remaining-command-line-arguments '#())
 
    (seq
-    (let flags-loop ([args (list-tail the-command-line-arguments 5)]
+    (let flags-loop ([args (list-tail the-command-line-arguments 6)]
                      [saw (hasheq)])
       ;; An element of `args` can become `(cons _arg _within-arg)`
       ;; due to splitting multiple flags with a single "-"