diff --git a/pkgs/racket-doc/scribblings/reference/startup.scrbl b/pkgs/racket-doc/scribblings/reference/startup.scrbl
index 063fc18454..740189678f 100644
--- a/pkgs/racket-doc/scribblings/reference/startup.scrbl
+++ b/pkgs/racket-doc/scribblings/reference/startup.scrbl
@@ -195,7 +195,9 @@ flags:
         @nonterm{m} and from @nonterm{m} to @nonterm{p}. (On Mac OS,
         @nonterm{n}, @nonterm{m}, and @nonterm{p} are relative to a
         @tt{__PLTSCHEME} segment in the executable. On Windows,
-        they are relative to a resource of type 257 and ID 1.) The first range
+        they are relative to a resource of type 257 and ID 1. On Unix
+        using ELF, they are relative to the @tt{.rackprog} segment
+        in the executable.) The first range
         is loaded in every new @tech{place}, and any modules declared
         in that range are considered predefined in the sense of
         @racket[module-predefined?]. This option is normally embedded
@@ -203,7 +205,7 @@ flags:
 
   @item{@FlagFirst{Y} @nonterm{file} @nonterm{n} @nonterm{m} @nonterm{p} :
         Like @Flag{k} @nonterm{n} @nonterm{m} @nonterm{p}, but reading
-        from @nonterm{file} (without any adjustment on Mac OS or Windows
+        from @nonterm{file} (without any adjustment
         for a segment or resource offset).}
 
   @item{@FlagFirst{m} or @DFlagFirst{main} : Evaluates a call to
diff --git a/racket/collects/compiler/embed.rkt b/racket/collects/compiler/embed.rkt
index 954e9dfff9..b1aa836aad 100644
--- a/racket/collects/compiler/embed.rkt
+++ b/racket/collects/compiler/embed.rkt
@@ -1511,9 +1511,7 @@
                              (let ([m (assq 'original-exe? aux)])
                                (or (not m)
                                    (not (cdr m))))))
-  (define long-cmdline? (or (eq? (cross-system-type) 'windows)
-                            (eq? (cross-system-type) 'macosx)
-                            unix-starter?))
+  (define long-cmdline? #t)
   (define relative? (let ([m (assq 'relative? aux)])
                       (and m (cdr m))))
   (define collects-path-bytes (collects-path->bytes 
@@ -1762,15 +1760,18 @@
 				new-rsrcs))
 			  (update-resources dest-exe pe new+dll-rsrcs)
                           (values 0 decl-len init-len (+ init-len cmdline-len))]
-                         [(and (eq? (cross-system-type) 'macosx)
-                               (not unix-starter?))
+                         [(memq (cross-system-type 'os*) '(macosx darwin))
                           ;; For Mach-O, we know how to add a proper segment
+                          (remove-signature dest-exe) ; may be needed in 'darwin mode
                           (define s (open-output-bytes))
                           (define decl-len (write-module s))
                           (let* ([s (get-output-bytes s)]
                                  [cl (let ([o (open-output-bytes)])
                                        ;; position is relative to __PLTSCHEME:
-                                       (write-cmdline (make-full-cmdline 0 decl-len (bytes-length s)) o)
+                                       (let ([cmdline (make-full-cmdline 0 decl-len (bytes-length s))])
+                                         (cond
+                                           [unix-starter? (display (make-starter-cmdline cmdline) o)]
+                                           [else (write-cmdline cmdline o)]))
                                        (get-output-bytes o))])
                             (let ([start (add-plt-segment 
                                           dest-exe 
@@ -1783,28 +1784,25 @@
                                         (+ start (bytes-length s))
                                         (+ start (bytes-length s) (bytes-length cl))))))]
                          [else
-                          ;; Unix starter: Maybe ELF, in which case we 
+                          ;; Unix starter or direct embedding: Maybe ELF, in which case we 
                           ;; can add a proper section
                           (define-values (s e dl p)
-                            (if unix-starter?
-                                (add-racket-section 
-                                 orig-exe 
-                                 dest-exe
-                                 (if launcher? #".rackcmdl" #".rackprog")
-                                 (lambda (start)
-                                   (let ([s (open-output-bytes)])
-                                     (define decl-len (write-module s))
-                                     (let ([p (file-position s)])
-                                       (display (make-starter-cmdline
-                                                 (make-full-cmdline start 
-                                                                    (+ start decl-len)
-                                                                    (+ start p)))
-                                                s)
-                                       (values (get-output-bytes s) decl-len p)))))
-                                (values #f #f #f #f)))
+                            (add-racket-section 
+                             orig-exe 
+                             dest-exe
+                             #".rackprog"
+                             (lambda (start)
+                               (let ([s (open-output-bytes)])
+                                 (define decl-len (write-module s))
+                                 (let ([p (file-position s)])
+				   (let ([cmdline (make-full-cmdline 0 decl-len p)])
+				     (cond
+				      [unix-starter? (display (make-starter-cmdline cmdline) s)]
+				      [else (write-cmdline cmdline s)]))
+                                   (values (get-output-bytes s) decl-len p))))))
                           (if (and s e)
-                             ;; ELF succeeded:
-                             (values s (+ s dl) (+ s p) e)
+                             ;; ELF succeeded, so make values relative to start:
+                             (values 0 dl p (- e s))
                              ;; Otherwise, just add to the end of the file:
                              (let ([start (file-size dest-exe)])
                                (define decl-end
@@ -1849,11 +1847,11 @@
                                                      "exeuctable type"
                                                      #"bINARy tYPe:"))))]
                          [cmdline (if cmdline-end
-					  #f
-					  (make-starter-cmdline full-cmdline))]
+                                      #f
+                                      (make-starter-cmdline full-cmdline))]
                          [out (open-output-file dest-exe #:exists 'update)])
                      (let ([old-cmdline-end cmdline-end]
-			       [cmdline-end (or cmdline-end (+ end (bytes-length cmdline)))]
+                           [cmdline-end (or cmdline-end (+ end (bytes-length cmdline)))]
                            [write-num (lambda (n)
                                         (write-bytes (integer->integer-bytes n 4 #t #f) out))])
                        (dynamic-wind
@@ -1879,10 +1877,10 @@
                           (write-num (length full-cmdline))
                           (write-num (if mred? 1 0))
                           (flush-output out)
-			      (unless old-cmdline-end
-				(file-position out end)
-				(write-bytes cmdline out)
-				(flush-output out)))
+                          (unless old-cmdline-end
+                            (file-position out end)
+                            (write-bytes cmdline out)
+                            (flush-output out)))
                         (lambda ()
                           (close-output-port out)))))]
                   [else
@@ -1936,7 +1934,7 @@
                                    (assq 'subsystem aux))])
                        (when m
                          (set-subsystem dest-exe (cdr m)))))]))))
-          (when (eq? (cross-system-type) 'macosx)
+          (when (memq (cross-system-type 'os*) '(macosx darwin))
             (add-ad-hoc-signature dest-exe))
           (done-writable dest-exe old-perms))))))
 
diff --git a/racket/collects/ffi/unsafe/nsalloc.rkt b/racket/collects/ffi/unsafe/nsalloc.rkt
index 496984ac88..d1379866eb 100644
--- a/racket/collects/ffi/unsafe/nsalloc.rkt
+++ b/racket/collects/ffi/unsafe/nsalloc.rkt
@@ -7,9 +7,10 @@
                       call-with-autorelease))
 
 ;; Make sure Foundation is loaded:
-(when (eq? 'macosx (system-type))
-  (void (ffi-lib "/System/Library/Frameworks/Foundation.framework/Foundation"
-                 #:fail (lambda () #f))))
+(case (system-type 'os*)
+  [(macosx darwin)
+   (void (ffi-lib "/System/Library/Frameworks/Foundation.framework/Foundation"
+                  #:fail (lambda () #f)))])
 
 (import-class NSAutoreleasePool)
 
diff --git a/racket/collects/net/osx-ssl.rkt b/racket/collects/net/osx-ssl.rkt
index 6a5029a7cf..8e9f903035 100644
--- a/racket/collects/net/osx-ssl.rkt
+++ b/racket/collects/net/osx-ssl.rkt
@@ -17,16 +17,19 @@
          osx-old-openssl?)
 
 (define (osx-old-openssl?)
-  (and (eq? 'macosx (system-type))
+  (and (or (eq? 'macosx (system-type))
+           (eq? 'darwin (system-type 'os*)))
        (not (eq? 'ppc (system-type 'arch))) ; Mac OS 10.5 is too old for this to work?
        (or (not ssl-available?)
            (not (memq 'tls12 (supported-client-protocols))))))
 
 (define cf-lib
-  (and (eq? 'macosx (system-type))
+  (and (or (eq? 'macosx (system-type))
+           (eq? 'darwin (system-type 'os*)))
        (ffi-lib "/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation")))
 (define net-lib
-  (and (eq? 'macosx (system-type))
+  (and (or (eq? 'macosx (system-type))
+           (eq? 'darwin (system-type 'os*)))
        (ffi-lib
         "/System/Library/Frameworks/CFNetwork.framework/CFNetwork"
         #:fail (lambda ()
diff --git a/racket/collects/openssl/mzssl.rkt b/racket/collects/openssl/mzssl.rkt
index b824a414cf..703d158f0b 100644
--- a/racket/collects/openssl/mzssl.rkt
+++ b/racket/collects/openssl/mzssl.rkt
@@ -479,12 +479,12 @@ TO DO:
 
 (define ssl-default-verify-sources
   (make-parameter
-   (case (system-type)
+   (case (system-type 'os*)
      [(windows)
       ;; On Windows, x509-root-sources produces paths like "/usr/local/ssl/certs", which
       ;; aren't useful. So just skip them.
       '((win32-store "ROOT"))]
-     [(macosx)
+     [(macosx darwin)
       '((macosx-keychain "/System/Library/Keychains/SystemRootCertificates.keychain"))]
      [else
       (x509-root-sources)])))
diff --git a/racket/collects/openssl/private/macosx.rkt b/racket/collects/openssl/private/macosx.rkt
index 126c578a6c..d67c4dcdd1 100644
--- a/racket/collects/openssl/private/macosx.rkt
+++ b/racket/collects/openssl/private/macosx.rkt
@@ -16,8 +16,8 @@
 ;; security export -k /System/Library/Keychains/... -t certs -f pemseq -o foo.pem
 
 (define libcf
-  (case (system-type)
-    [(macosx) (ffi-lib "/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation")]
+  (case (system-type 'os*)
+    [(macosx darwin) (ffi-lib "/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation")]
     [else #f]))
 
 (define-ffi-definer define-cf libcf
@@ -47,8 +47,8 @@
 ;; ----
 
 (define libsec
-  (case (system-type)
-    [(macosx) (ffi-lib "/System/Library/Frameworks/Security.framework/Security")]
+  (case (system-type 'os*)
+    [(macosx darwin) (ffi-lib "/System/Library/Frameworks/Security.framework/Security")]
     [else #f]))
 (define-ffi-definer define-sec libsec
   #:default-make-fail make-not-available)
diff --git a/racket/src/bc/Makefile.in b/racket/src/bc/Makefile.in
index 985f54e934..3393e0c55e 100644
--- a/racket/src/bc/Makefile.in
+++ b/racket/src/bc/Makefile.in
@@ -304,7 +304,7 @@ DEF_C_DIRS = $(DEF_COLLECTS_DIR) $(DEF_CONFIG_DIR)
 MAIN_HEADER_DEPS = $(srcdir)/include/scheme.h $(srcdir)/include/schthread.h $(srcdir)/sconfig.h \
                    $(srcdir)/src/stypes.h $(srcdir)/cmdline.inc $(srcdir)/../start/parse_cmdl.inc \
                    $(srcdir)/../start/cmdl_to_argv.inc \
-	           $(srcdir)/../start/config.inc $(srcdir)/../start/delayed.inc \
+	           $(srcdir)/../start/config.inc $(srcdir)/../start/self_exe.inc $(srcdir)/../start/delayed.inc \
 	           $(srcdir)/../start/embedded_dll.inc
 
 MAIN_INCLUDES = -I$(builddir) -I$(srcdir)/include -I$(srcdir)/../version
@@ -499,6 +499,7 @@ unix-install-cgc:
 	cd ..; $(STRIP_DEBUG) "$(DESTDIR)$(bindir)/racket@CGC_INSTALLED@"
 	cd ..; cp bc/mzdyn.o "$(DESTDIR)$(libpltdir)/mzdyn.o"
 	@RUN_RACKET_CGC@ $(SETUP_BOOT_COLLECTS_PATH) "$(DESTDIR)$(bindir)/racket@CGC_INSTALLED@@EXE_SUFFIX@" $(DESTDIR)@COLLECTS_PATH@ $(DESTDIR)@CONFIG_PATH@
+	$(RESTORE_SIGNATURE) "$(DESTDIR)$(bindir)/racket@CGC_INSTALLED@"
 
 unix-install-libs-cgc:
 	cd ..; $(ICP_LIB) bc/libmzgc.@LIBSFX@ "$(DESTDIR)$(libdir)/libmzgc.@LIBSFX@"
@@ -520,6 +521,7 @@ unix-install-3m:
 	$(MAKE) unix-@INSTALL_LIBS_ENABLE@-libs-3m
 	cd ..; $(ICP) bc/mzdyn3m.o "$(DESTDIR)$(libpltdir)/mzdyn3m.o"
 	@RUN_RACKET_MMM@ $(SETUP_BOOT_COLLECTS_PATH) "$(DESTDIR)$(bindir)/racket@MMM_INSTALLED@@EXE_SUFFIX@" $(DESTDIR)@COLLECTS_PATH@ $(DESTDIR)@CONFIG_PATH@
+	$(RESTORE_SIGNATURE) "$(DESTDIR)$(bindir)/racket@MMM_INSTALLED@"
 
 unix-install-libs-3m:
 	cd ..; $(ICP_LIB) bc/libracket3m.@LIBSFX@ "$(DESTDIR)$(libdir)/libracket3m.@LIBSFX@"
@@ -604,6 +606,7 @@ osx-install-cgc:
 	$(MAKE) unix-install-cgc
 	mkdir -p $(DESTDIR)$(MZFWDIR)/Versions/$(FWVERSION)
 	cp $(MZFW) $(DESTDIR)$(MZFWDIR)/Versions/$(FWVERSION)/
+	$(STRIP_SIGNATURE) $(DESTDIR)"$(bindir)/racket@CGC_INSTALLED@"
 	/usr/bin/install_name_tool -change "@executable_path/Racket.framework/Versions/$(FWVERSION)/Racket" "@FRAMEWORK_PREFIX@Racket.framework/Versions/$(FWVERSION)/Racket" $(DESTDIR)"$(bindir)/racket@CGC_INSTALLED@"
 	$(RESTORE_SIGNATURE) $(DESTDIR)"$(bindir)/racket@CGC_INSTALLED@"
 
@@ -615,6 +618,7 @@ osx-install-3m:
 	$(MAKE) unix-install-3m
 	mkdir -p $(DESTDIR)"$(MZFWDIR)/Versions/$(FWVERSION)_3m"
 	cp $(MZFWMMM) $(DESTDIR)$(MZFWDIR)/Versions/$(FWVERSION)_3m/
+	$(STRIP_SIGNATURE) $(DESTDIR)"$(bindir)/racket@MMM_INSTALLED@"
 	/usr/bin/install_name_tool -change "@executable_path/Racket.framework/Versions/$(FWVERSION)_3m/Racket" "@FRAMEWORK_PREFIX@Racket.framework/Versions/$(FWVERSION)_3m/Racket" $(DESTDIR)"$(bindir)/racket@MMM_INSTALLED@"
 	$(RESTORE_SIGNATURE) $(DESTDIR)"$(bindir)/racket@MMM_INSTALLED@"
 
diff --git a/racket/src/bc/cmdline.inc b/racket/src/bc/cmdline.inc
index 4274b8d889..81bb27d936 100644
--- a/racket/src/bc/cmdline.inc
+++ b/racket/src/bc/cmdline.inc
@@ -42,7 +42,6 @@ static int is_number_arg(const char *s)
   return 1;
 }
 
-#if defined(OS_X) || defined(DOS_FILE_SYSTEM)
 char *add_to_str(const char *addr, long amt)
 {
   long addr_v;
@@ -51,23 +50,19 @@ char *add_to_str(const char *addr, long amt)
   sprintf(buf, "%ld", addr_v);
   return strdup(buf);
 }
-#endif
 
-static char *make_embedded_load(const char *file, const char *start, const char *end)
+static char *make_embedded_load(const self_exe_t self_exe, const char *file, const char *start, const char *end)
 {
   char *s;
   int slen, elen, flen;
 
-#if defined(OS_X) || defined(DOS_FILE_SYSTEM)
   if (file == NULL) {
     long fileoff;
-    fileoff = get_segment_offset();
+    fileoff = get_segment_offset(self_exe);
     start = add_to_str(start, fileoff);
     end = add_to_str(end, fileoff);
+    file = SELF_PATH_TO_BYTES(self_exe);
   }
-#endif
-
-  if (!file) file = "";
 
   slen = strlen(start);
   elen = strlen(end);
@@ -730,6 +725,7 @@ static int run_from_cmd_line(int argc, char *_argv[],
   Scheme_Object *syslog_level = NULL, *stderr_level = NULL, *stdout_level = NULL;
   FinishArgs *fa;
   FinishArgsAtoms *fa_a;
+  self_exe_t self_exe;
 
   scheme_set_default_locale();
 
@@ -740,8 +736,10 @@ static int run_from_cmd_line(int argc, char *_argv[],
 #ifdef NEED_CONSOLE_PRINTF
   console_printf = scheme_get_console_printf();
 #endif
-  
-  extract_built_in_arguments(&prog, &sprog, &argc, &argv);
+
+  self_exe = get_self_path(prog);
+
+  extract_built_in_arguments(self_exe, &prog, &sprog, &argc, &argv);
 
 #ifndef DONT_PARSE_COMMAND_LINE
   evals_and_loads = (char **)malloc(sizeof(char *) * argc);
@@ -1024,12 +1022,12 @@ static int run_from_cmd_line(int argc, char *_argv[],
 	  }
 	  argv++;
 	  --argc;
-	  se = make_embedded_load(embedding_file, argv[0], argv[1]);
+	  se = make_embedded_load(self_exe, embedding_file, argv[0], argv[1]);
 	  evals_and_loads[num_enl] = se;
 	  argv++;
 	  --argc;
 	  eval_kind[num_enl++] = mzcmd_EMBEDDED_REG;
-	  se = make_embedded_load(embedding_file, argv[0], argv[1]);
+	  se = make_embedded_load(self_exe, embedding_file, argv[0], argv[1]);
 	  evals_and_loads[num_enl] = se;
 	  argv++;
 	  --argc;
diff --git a/racket/src/bc/dynsrc/Makefile.in b/racket/src/bc/dynsrc/Makefile.in
index 13d63d1c6a..771f13149e 100644
--- a/racket/src/bc/dynsrc/Makefile.in
+++ b/racket/src/bc/dynsrc/Makefile.in
@@ -60,7 +60,7 @@ MZDYNDEP = ../mzdyn.o $(srcdir)/../include/ext.exp $(srcdir)/../include/racket.e
 dynexmpl.o: $(srcdir)/dynexmpl.c  $(HEADERS)
 	$(PLAIN_CC) $(ALL_CFLAGS) -c $(srcdir)/dynexmpl.c -o dynexmpl.o
 
-../starter@NOT_MINGW@@EXE_SUFFIX@: $(srcdir)/../../start/ustart.c $(srcdir)/../../start/unix_self.inc
+../starter@NOT_MINGW@@EXE_SUFFIX@: $(srcdir)/../../start/ustart.c $(srcdir)/../../start/self_exe.inc
 	$(PLAIN_CC) $(ALL_CFLAGS) -o ../starter@EXE_SUFFIX@ $(srcdir)/../../start/ustart.c
 
 PARSE_CMDL = $(srcdir)/../../start/parse_cmdl.inc
diff --git a/racket/src/bc/gracket/Makefile.in b/racket/src/bc/gracket/Makefile.in
index 0b63a5f92b..b89a975309 100644
--- a/racket/src/bc/gracket/Makefile.in
+++ b/racket/src/bc/gracket/Makefile.in
@@ -57,6 +57,9 @@ LDFLAGS = @LDFLAGS@
 ARLIBFLAGS = $(LDFLAGS) $(LDLIBS)
 ###########################
 
+STRIP_SIGNATURE = @STRIP_SIGNATURE@
+RESTORE_SIGNATURE = @RESTORE_SIGNATURE@ "${srcdir}/../../mac/entitlements.plist"
+
 GRACKETLINKER = @MZLINKER@
 
 LIBRKTIO = ../rktio/librktio.@LTA@
@@ -224,8 +227,10 @@ GRACKET_NAME@MINGW@ = GRacket
 install-wx_xt-cgc:
 	$(MAKE) @MRLIBINSTALL@-cgc-wx_xt
 	cd ..; $(ICP) gracket/gracket@CGC@@EXE_SUFFIX@ "$(DESTDIR)$(libpltdir)/$(GRACKET_NAME)@CGC_INSTALLED@@EXE_SUFFIX@"
+	$(STRIP_SIGNATURE) "$(DESTDIR)$(libpltdir)/$(GRACKET_NAME)@CGC_INSTALLED@@EXE_SUFFIX@"
 	cd ..; @STRIP_DEBUG@ "$(DESTDIR)$(libpltdir)/$(GRACKET_NAME)@CGC_INSTALLED@@EXE_SUFFIX@"
 	@RUN_RACKET_CGC@ $(SETUP_BOOT_COLLECTS_PATH) @DIRCVTPRE@"$(DESTDIR)$(libpltdir)/$(GRACKET_NAME)@CGC_INSTALLED@@EXE_SUFFIX@"@DIRCVTPOST@ @GUI_COLLECTS_PATH@ @GUI_CONFIG_PATH@
+	$(RESTORE_SIGNATURE) "$(DESTDIR)$(libpltdir)/$(GRACKET_NAME)@CGC_INSTALLED@@EXE_SUFFIX@"
 
 install-wx_xt-cgc-final:
 	$(NOOP)
@@ -239,8 +244,10 @@ install-lib-3m-wx_xt:
 install-wx_xt-3m:
 	$(MAKE) @MRLIBINSTALL@-3m-wx_xt
 	cd ..; $(ICP) gracket/gracket@MMM@@EXE_SUFFIX@ "$(DESTDIR)$(libpltdir)/$(GRACKET_NAME)@MMM_INSTALLED@@EXE_SUFFIX@"
+	$(STRIP_SIGNATURE) "$(DESTDIR)$(libpltdir)/$(GRACKET_NAME)@MMM_INSTALLED@@EXE_SUFFIX@"
 	cd ..; @STRIP_DEBUG@ "$(DESTDIR)$(libpltdir)/$(GRACKET_NAME)@MMM_INSTALLED@@EXE_SUFFIX@"
 	@RUN_RACKET_MMM@ $(SETUP_BOOT_COLLECTS_PATH) @DIRCVTPRE@"$(DESTDIR)$(libpltdir)/$(GRACKET_NAME)@MMM_INSTALLED@@EXE_SUFFIX@"@DIRCVTPOST@ @GUI_COLLECTS_PATH@ @GUI_CONFIG_PATH@
+	$(RESTORE_SIGNATURE) "$(DESTDIR)$(libpltdir)/$(GRACKET_NAME)@MMM_INSTALLED@@EXE_SUFFIX@"
 
 install-wx_xt-3m-final:
 	$(NOOP)
diff --git a/racket/src/cs/Makefile b/racket/src/cs/Makefile
index 6b8f0e98ea..aa54535413 100644
--- a/racket/src/cs/Makefile
+++ b/racket/src/cs/Makefile
@@ -32,7 +32,7 @@ EXTRA_COMPILE_DEPS =
 COMPILE_FILE = $(SCHEME) --script compile-file.ss $(UNSAFE_COMP) $(COMPRESS_COMP) $(DEBUG_COMP) $(CROSS_COMP) --dest "$(BUILDDIR)"
 COMPILE_FILE_DEPS = compile-file.ss include.ss place-register.ss $(EXTRA_COMPILE_DEPS)
 
-RACKET_SETUP_ARGS = false ../../bin/racket ../../bin/racket ../collects ../etc 0 false false 0 ""
+RACKET_SETUP_ARGS = false ../../bin/racket ../../bin/racket ../collects ../etc "" 0 false false 0 ""
 
 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 f223a00ac9..262c920ff8 100644
--- a/racket/src/cs/c/Makefile.in
+++ b/racket/src/cs/c/Makefile.in
@@ -212,12 +212,12 @@ racket.boot: racket.so
 EMBED_DEPS = $(srcdir)/embed-boot.rkt
 
 racketcs@NOT_OSX@@NOT_MINGW@: raw_racketcs petite-v.boot scheme-v.boot racket-v.boot $(EMBED_DEPS)
-	$(BOOTSTRAP_RACKET) $(srcdir)/embed-boot.rkt @ELF_COMP@ --target $(TARGET_MACH) @BOOT_COMPRESS_COMP@ raw_racketcs racketcs petite-v.boot scheme-v.boot racket-v.boot
+	$(BOOTSTRAP_RACKET) $(srcdir)/embed-boot.rkt --target $(TARGET_MACH) @BOOT_COMPRESS_COMP@ raw_racketcs racketcs petite-v.boot scheme-v.boot racket-v.boot
 	@POST_LINKER@ racketcs
 	$(RESTORE_SIGNATURE) racketcs
 
 gracketcs@NOT_OSX@@NOT_MINGW@: raw_gracketcs petite-v.boot scheme-v.boot racket-v.boot $(EMBED_DEPS)
-	$(BOOTSTRAP_RACKET) $(srcdir)/embed-boot.rkt @ELF_COMP@ --target $(TARGET_MACH) @BOOT_COMPRESS_COMP@ raw_gracketcs gracketcs petite-v.boot scheme-v.boot racket-v.boot
+	$(BOOTSTRAP_RACKET) $(srcdir)/embed-boot.rkt --target $(TARGET_MACH) @BOOT_COMPRESS_COMP@ raw_gracketcs gracketcs petite-v.boot scheme-v.boot racket-v.boot
 	@POST_LINKER@ gracketcs
 	$(RESTORE_SIGNATURE) gracketcs
 
@@ -433,7 +433,7 @@ DEF_C_DIRS = $(DEF_COLLECTS_DIR) $(DEF_CONFIG_DIR)
 
 MAIN_DEPS = $(srcdir)/main.c $(srcdir)/boot.h cs_config.h \
             $(srcdir)/../../start/config.inc \
-            $(srcdir)/../../start/unix_self.inc
+            $(srcdir)/../../start/self_exe.inc
 
 main.o: $(MAIN_DEPS)
 	$(CC) $(CFLAGS) $(DEF_C_DIRS) -c -o main.o $(srcdir)/main.c
@@ -444,7 +444,7 @@ grmain.o: $(srcdir)/grmain.c $(MAIN_DEPS) $(srcdir)/../../start/gui_filter.inc
 boot.o: $(srcdir)/boot.c $(srcdir)/../../rktio/rktio.inc $(srcdir)/boot.h
 	$(CC) $(CFLAGS) -c -o boot.o $(srcdir)/boot.c
 
-starter@NOT_MINGW@: $(srcdir)/../../start/ustart.c $(srcdir)/../../start/unix_self.inc
+starter@NOT_MINGW@: $(srcdir)/../../start/ustart.c $(srcdir)/../../start/self_exe.inc
 	$(CC) $(CFLAGS) -o starter $(srcdir)/../../start/ustart.c
 
 
diff --git a/racket/src/cs/c/boot.c b/racket/src/cs/c/boot.c
index 13aa0b8e50..5d7c98a712 100644
--- a/racket/src/cs/c/boot.c
+++ b/racket/src/cs/c/boot.c
@@ -192,9 +192,10 @@ void racket_boot(racket_boot_arguments_t *ba)
     l = Scons(Sbytevector(ba->cs_compiled_subdir ? "true" : "false"), l);
     sprintf(segment_offset_s, "%ld", ba->segment_offset);
     l = Scons(Sbytevector(segment_offset_s), l);
+    l = Scons(Sbytevector(ba->k_file ? (char *)ba->k_file : (char *)ba->exec_file), l);
     l = Scons(Sbytevector(ba->config_dir ? (char *)ba->config_dir : "etc"), l);
     l = Scons(parse_coldirs(ba->collects_dir ? (char *)ba->collects_dir : ""), l);
-    l = Scons(Sbytevector(ba->run_file ? (char *)ba->run_file : (char *)ba->exec_file ), l);
+    l = Scons(Sbytevector(ba->run_file ? (char *)ba->run_file : (char *)ba->exec_file), l);
     l = Scons(Sbytevector((char *)ba->exec_file), l);
     l = Scons(Sbytevector(ba->exit_after ? "false" : "true"), l);
 
diff --git a/racket/src/cs/c/boot.h b/racket/src/cs/c/boot.h
index f9560ba94c..e7af14110a 100644
--- a/racket/src/cs/c/boot.h
+++ b/racket/src/cs/c/boot.h
@@ -30,6 +30,7 @@ typedef struct racket_boot_arguments_t {
   const char *collects_dir;   /* can be NULL or "" to disable collection path */
   const char *config_dir; /* use NULL or "etc" if you don't care */
   /* wchar_t * */void *dll_dir; /* can be NULL for default */
+  const char *k_file;     /* for -k; can be NULL for the same as `exec_file` */
 
   /* How to initialize `use-compiled-file-paths`: */
   int cs_compiled_subdir; /* true => subdirectory of "compiled" */
diff --git a/racket/src/cs/c/configure b/racket/src/cs/c/configure
index 6178369e41..57a598ac78 100755
--- a/racket/src/cs/c/configure
+++ b/racket/src/cs/c/configure
@@ -639,7 +639,6 @@ FRAMEWORK_INSTALL_DIR
 SCHEME_CROSS_CONFIG_ARGS
 SCHEME_CONFIG_ARGS
 MAKE_BUILD_SCHEME
-ELF_COMP
 BOOT_COMPRESS_COMP
 COMPRESS_COMP
 CONFIGURE_RACKET_SO_COMPILE
@@ -3222,7 +3221,6 @@ NOT_MINGW=""
 CONFIGURE_RACKET_SO_COMPILE=""
 COMPRESS_COMP=""
 BOOT_COMPRESS_COMP=""
-ELF_COMP=""
 POST_LINKER="echo"
 
 FRAMEWORK_INSTALL_DIR='$(libpltdir)'
@@ -4336,7 +4334,6 @@ case "$host_os" in
     LIBS="$LIBS -lsocket -lnsl -lintl"
     use_flag_pthread="no"
     use_flag_posix_pthread="yes"
-    enable_strip=no
     ;;
   aix*)
     ;;
@@ -4347,8 +4344,6 @@ case "$host_os" in
     LIBS="${LIBS} -lm -lpthread"
     LINK_DYNAMIC="-rdynamic"
     add_iconv_lib="-liconv"
-    CPPFLAGS="${CPPFLAGS} -DELF_FIND_BOOT_SECTION"
-    ELF_COMP="--expect-elf"
     ;;
   openbsd*)
     MACH_OS=ob
@@ -4358,8 +4353,6 @@ case "$host_os" in
     LINK_DYNAMIC="-Wl,--export-dynamic"
     add_iconv_lib="-liconv"
     LDFLAGS="${LDFLAGS} -Wl,-zwxneeded"
-    CPPFLAGS="${CPPFLAGS} -DELF_FIND_BOOT_SECTION"
-    ELF_COMP="--expect-elf"
     ;;
   bitrig*)
     LINK_DYNAMIC="-Wl,--export-dynamic"
@@ -4372,8 +4365,6 @@ case "$host_os" in
     LIBS="${LIBS} -lm -lpthread"
     LINK_DYNAMIC="-rdynamic"
     add_iconv_lib="/usr/lib/i18n/libiconv_std.a"
-    CPPFLAGS="${CPPFLAGS} -DELF_FIND_BOOT_SECTION"
-    ELF_COMP="--expect-elf"
     POST_LINKER="paxctl +m"
     ;;
   irix*)
@@ -4387,9 +4378,7 @@ case "$host_os" in
         LIBS="${LIBS} -lrt"
         ;;
     esac
-    CPPFLAGS="${CPPFLAGS} -DELF_FIND_BOOT_SECTION"
     LINK_DYNAMIC="-rdynamic"
-    ELF_COMP="--expect-elf"
     ;;
   osf1*)
     ;;
@@ -5793,7 +5782,6 @@ SCHEME_CROSS_CONFIG_ARGS="--machine=${TARGET_MACH} --disable-x11 ${cs_auto_flags
 
 
 
-
 
 
 makefiles="Makefile"
diff --git a/racket/src/cs/c/configure.ac b/racket/src/cs/c/configure.ac
index c5299fc1ed..b29cacf941 100644
--- a/racket/src/cs/c/configure.ac
+++ b/racket/src/cs/c/configure.ac
@@ -140,7 +140,6 @@ NOT_MINGW=""
 CONFIGURE_RACKET_SO_COMPILE=""
 COMPRESS_COMP=""
 BOOT_COMPRESS_COMP=""
-ELF_COMP=""
 POST_LINKER="echo"
 
 FRAMEWORK_INSTALL_DIR='$(libpltdir)'
@@ -218,7 +217,6 @@ case "$host_os" in
     LIBS="$LIBS -lsocket -lnsl -lintl"
     use_flag_pthread="no"
     use_flag_posix_pthread="yes"
-    enable_strip=no
     ;;
   aix*)
     ;;
@@ -229,8 +227,6 @@ case "$host_os" in
     LIBS="${LIBS} -lm -lpthread"
     LINK_DYNAMIC="-rdynamic"
     add_iconv_lib="-liconv"
-    CPPFLAGS="${CPPFLAGS} -DELF_FIND_BOOT_SECTION"
-    ELF_COMP="--expect-elf"
     ;;
   openbsd*)
     MACH_OS=ob
@@ -240,8 +236,6 @@ case "$host_os" in
     LINK_DYNAMIC="-Wl,--export-dynamic"
     add_iconv_lib="-liconv"
     LDFLAGS="${LDFLAGS} -Wl,-zwxneeded"
-    CPPFLAGS="${CPPFLAGS} -DELF_FIND_BOOT_SECTION"
-    ELF_COMP="--expect-elf"
     ;;
   bitrig*)
     LINK_DYNAMIC="-Wl,--export-dynamic"
@@ -254,8 +248,6 @@ case "$host_os" in
     LIBS="${LIBS} -lm -lpthread"
     LINK_DYNAMIC="-rdynamic"
     add_iconv_lib="/usr/lib/i18n/libiconv_std.a"
-    CPPFLAGS="${CPPFLAGS} -DELF_FIND_BOOT_SECTION"
-    ELF_COMP="--expect-elf"
     POST_LINKER="paxctl +m"
     ;;
   irix*)
@@ -269,9 +261,7 @@ case "$host_os" in
         LIBS="${LIBS} -lrt"
         ;;
     esac
-    CPPFLAGS="${CPPFLAGS} -DELF_FIND_BOOT_SECTION"
     LINK_DYNAMIC="-rdynamic"
-    ELF_COMP="--expect-elf"
     ;;
   osf1*)
     ;;
@@ -819,7 +809,6 @@ AC_SUBST(LZ4_LIB_UNPACK)
 AC_SUBST(CONFIGURE_RACKET_SO_COMPILE)
 AC_SUBST(COMPRESS_COMP)
 AC_SUBST(BOOT_COMPRESS_COMP)
-AC_SUBST(ELF_COMP)
 AC_SUBST(MAKE_BUILD_SCHEME)
 AC_SUBST(SCHEME_CONFIG_ARGS)
 AC_SUBST(SCHEME_CROSS_CONFIG_ARGS)
diff --git a/racket/src/cs/c/embed-boot.rkt b/racket/src/cs/c/embed-boot.rkt
index e6c8d71e4d..f9093576d1 100644
--- a/racket/src/cs/c/embed-boot.rkt
+++ b/racket/src/cs/c/embed-boot.rkt
@@ -6,7 +6,6 @@
          compiler/private/elf
          "adjust-compress.rkt")
 
-(define expect-elf? #f)
 (define alt-dests '())
 (define target #f)
 
@@ -14,8 +13,6 @@
  #:once-each
  [("--compress") "Leave compiled code files as compressed"
   (enable-compress!)]
- [("--expect-elf") "Record offset from ELF section"
-  (set! expect-elf? #t)]
  [("--target") machine "Select target machine"
   (set! target machine)]
  #:multi
@@ -57,7 +54,10 @@
          "x86_64-darwin" "i386-darwin" "aarch64-darwin"
          "x86_64-macosx" "i386-macosx" "aarch64-macosx")
         ;; Mach-O
-        (copy-file use-src-file dest-file #t)
+        (when (file-exists? dest-file)
+          ;; explicit delete to avoid signature unhappiness
+          (delete-file dest-file))
+        (copy-file use-src-file dest-file)
         (remove-signature dest-file)
         (add-plt-segment dest-file data #:name #"__RKTBOOT")
         ;; Find segment at run time:
@@ -86,12 +86,8 @@
           [start-pos
            ;; Success as ELF
            (file-or-directory-permissions dest-file (file-or-directory-permissions use-src-file 'bits))
-           (cond
-             [expect-elf?
-              ;; Find ".rackboot" at run time:
-              0]
-             [else
-              start-pos])]
+           ;; Find ".rackboot" at run time:
+           0]
           [else
            ;; Not ELF; just append to the end
            (copy-file use-src-file dest-file #t)
@@ -102,8 +98,6 @@
             (lambda (o)
               (file-position o pos)
               (write-bytes data o)))
-           (when expect-elf?
-             (error 'embed-boot "expected ELF"))
            pos])]))
 
    (define (write-offsets dest-file)
diff --git a/racket/src/cs/c/main.c b/racket/src/cs/c/main.c
index c8457a4e8a..47dec88c21 100644
--- a/racket/src/cs/c/main.c
+++ b/racket/src/cs/c/main.c
@@ -57,34 +57,11 @@ PRESERVE_IN_EXECUTABLE
 char *boot_file_data = "BooT FilE OffsetS:\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
 static int boot_file_offset = 18;
 
-#include "../../start/unix_self.inc"
-
 #ifdef OS_X
 # include <mach-o/dyld.h>
 static long find_rktboot_section(char *me)
 {
-  const struct mach_header *mh;
-  const struct load_command *lc;
-  int i;
-
-  mh = _dyld_get_image_header(0);
-
-  lc = (void *)((char *)mh + ((mh->magic == 0xfeedfacf) ? sizeof(struct mach_header_64) : sizeof(struct mach_header)));
-
-  for (i = 0; i < mh->ncmds; i++) {
-    if (lc->cmd == LC_SEGMENT) {
-      const struct segment_command *sc = (struct segment_command *)lc;
-      if (!strcmp(sc->segname, "__RKTBOOT"))
-        return sc->fileoff;
-    } else if (lc->cmd == LC_SEGMENT_64) {
-      const struct segment_command_64 *sc = (struct segment_command_64 *)lc;
-      if (!strcmp(sc->segname, "__RKTBOOT"))
-        return sc->fileoff;
-    }
-    lc = (void *)((char *)lc + lc->cmdsize);
-  }
-
-  return 0;
+  return find_mach_o_segment("__RKTBOOT", NULL);
 }
 #endif
 
@@ -127,69 +104,18 @@ static char *path_append(const char *p1, char *p2) {
 
 #endif
 
-#ifdef ELF_FIND_BOOT_SECTION
-# include <elf.h>
-# include <fcntl.h>
-
-static long find_boot_section(char *me)
+#if !defined(WIN32) && !defined(OS_X)
+static long find_boot_section(const char *me)
 {
-  int fd, i;
-#if SIZEOF_VOID_P == 4
-  Elf32_Ehdr e;
-  Elf32_Shdr s;
-#else
-  Elf64_Ehdr e;
-  Elf64_Shdr s;
-#endif
-  char *strs;
+  int start = 0, end = 0;
+  
+  find_elf_section_offset(me, ".rackboot", &start, &end);
 
-  fd = open(me, O_RDONLY, 0);
-  if (fd == -1) return 0;
-
-  if (read(fd, &e, sizeof(e)) == sizeof(e)) {
-    lseek(fd, e.e_shoff + (e.e_shstrndx * e.e_shentsize), SEEK_SET);
-    if (read(fd, &s, sizeof(s)) != sizeof(s)) {
-      close(fd);
-      return 0;
-    }
-
-    strs = (char *)malloc(s.sh_size);
-    lseek(fd, s.sh_offset, SEEK_SET);
-    if (read(fd, strs, s.sh_size) != s.sh_size) {
-      close(fd);
-      return 0;
-    }
-
-    for (i = 0; i < e.e_shnum; i++) {
-      lseek(fd, e.e_shoff + (i * e.e_shentsize), SEEK_SET);
-      if (read(fd, &s, sizeof(s)) != sizeof(s)) {
-        close(fd);
-        return 0;
-      }
-      if (!strcmp(strs + s.sh_name, ".rackboot")) {
-        close(fd);
-        return s.sh_offset;
-      }
-    }
-  }
-
-  close(fd);
-  return 0;
+  return start;
 }
 #endif
 
 #ifdef WIN32
-static char *string_to_utf8(wchar_t *p)
-{
-  char *r;
-  int len;
-
-  len = WideCharToMultiByte(CP_UTF8, 0, p, -1, NULL, 0, NULL, NULL);
-  r = malloc(len);
-  len = WideCharToMultiByte(CP_UTF8, 0, p, -1, r, len, NULL, NULL);
-
-  return r;
-}
 
 static int scheme_utf8_encode(unsigned int *path, int zero_offset, int len,
 			      char *dest, int offset, int get_utf16)
@@ -202,126 +128,6 @@ static int scheme_utf8_encode(unsigned int *path, int zero_offset, int len,
 }
 
 # include "../start/cmdl_to_argv.inc"
-
-# undef USE_GENERIC_GET_SELF_PATH
-#endif
-
-#ifdef USE_GENERIC_GET_SELF_PATH
-/* Get executable path via argv[0] and the `PATH` environment variable */
-
-static int has_slash(char *s)
-{
-  while (*s) {
-    if (s[0] == '/')
-      return 1;
-    s++;
-  }
-  return 0;
-}
-
-static char *do_path_append(char *s1, int l1, char *s2)
-{
-  int l2;
-  char *s;
-
-  l2 = strlen(s2);
-
-  s  = (char *)malloc(l1 + l2 + 2);
-
-  memcpy(s, s1, l1);
-  if (s[l1 - 1] != '/') {
-    s[l1++] = '/';
-  }
-
-  memcpy(s + l1, s2, l2);
-  s[l1 + l2] = 0;
-
-  return s;
-}
-
-static char *path_append(char *s1, char *s2)
-{
-  return do_path_append(s1, strlen(s1), s2);
-}
-
-static char *copy_string(char *s1)
-{
-  int l1;
-  char *s;
-
-  if (!s1) return NULL;
-
-  l1 = strlen(s1);
-
-  s  = (char *)malloc(l1 + 1);
-
-  memcpy(s, s1, l1 + 1);
-
-  return s;
-}
-
-static int executable_exists(char *path)
-{
-  return (access(path, X_OK) == 0);
-}
-
-static char *get_self_path(char *exec_file)
-{
-  if (exec_file[0] == '/') {
-    /* Absolute path */
-    return exec_file;
-  } else if (has_slash(exec_file)) {
-    /* Relative path with a directory: */
-    char *buf;
-    long buflen = 4096;
-    buf = (char *)malloc(buflen);
-    return path_append(getcwd(buf, buflen), exec_file);
-  } else {
-    /* We have to find the executable by searching PATH: */
-    char *path = copy_string(getenv("PATH")), *p, *m;
-    int more;
-
-    if (!path) {
-      path = "";
-    }
-
-    while (1) {
-      /* Try each element of path: */
-      for (p = path; *p && (*p != ':'); p++) { }
-      if (*p) {
-	*p = 0;
-	more = 1;
-      } else
-	more = 0;
-
-      if (!*path)
-	break;
-
-      m = path_append(path, exec_file);
-
-      if (executable_exists(m)) {
-	if (m[0] != '/')
-	  m = path_append(getcwd(NULL, 0), m);
-	return m;
-      }
-      free(m);
-
-      if (more)
-	path = p + 1;
-      else
-	break;
-    }
-
-    return exec_file;
-  }
-}
-#endif
-
-#ifdef NO_GET_SEGMENT_OFFSET
-static long get_segment_offset()
-{
-  return 0;
-}
 #endif
 
 #ifndef WIN32
@@ -355,6 +161,7 @@ static int bytes_main(int argc, char **argv,
 		      int wm_is_gracket_or_x11_arg_count, char *gracket_guid_or_x11_args)
 {
   char *boot_exe;
+  self_exe_t self_exe;
   char *exec_file = argv[0], *run_file = NULL;
   char *boot1_path, *boot2_path, *boot3_path;
   int boot1_offset, boot2_offset, boot3_offset, boot_end_offset;
@@ -374,12 +181,12 @@ static int bytes_main(int argc, char **argv,
     argv++;
   }
 
-  extract_built_in_arguments(&exec_file, &run_file, &argc, &argv);
+  self_exe = get_self_path(exec_file);
+
+  extract_built_in_arguments(self_exe, &exec_file, &run_file, &argc, &argv);
   if (!run_file)
     run_file = exec_file;
 
-  segment_offset = get_segment_offset();
-
   memcpy(&boot1_offset, boot_file_data + boot_file_offset, sizeof(boot1_offset));
   memcpy(&boot2_offset, boot_file_data + boot_file_offset + 4, sizeof(boot2_offset));
   memcpy(&boot3_offset, boot_file_data + boot_file_offset + 8, sizeof(boot3_offset));
@@ -393,7 +200,7 @@ static int bytes_main(int argc, char **argv,
     dll = embedded_dll_open("libracketcsxxxxxxx.dll", 1);
     boot_rsrc_offset = in_memory_get_offset("libracketcsxxxxxxx.dll");
     racket_boot_p = (racket_boot_t)scheme_dll_find_object(dll, "racket_boot");
-    dll_path = get_self_executable_path();
+    dll_path = self_exe;
   } else {
     HMODULE dll;
     dll_path = load_delayed_dll_x(NULL, "libracketcsxxxxxxx.dll", &dll);
@@ -402,18 +209,19 @@ static int bytes_main(int argc, char **argv,
   boot_exe = string_to_utf8(dll_path);
 # define racket_boot racket_boot_p
 #else
-  boot_exe = get_self_path(exec_file);
+  boot_exe = self_exe;
 #endif
 
-#ifdef ELF_FIND_BOOT_SECTION
-  boot_offset = find_boot_section(boot_exe);
-#elif defined(OS_X)
+  /* segment_offset is for embedded bytecode (not boot files) */
+  segment_offset = get_segment_offset(self_exe);
+
+#if defined(OS_X)
   boot_offset = find_rktboot_section(boot_exe);
   if (!boot_offset) boot_images_in_exe = 0;
 #elif WIN32
   boot_offset = find_resource_offset(dll_path, 259, boot_rsrc_offset);
 #else
-  boot_offset = 0;
+  boot_offset = find_boot_section(boot_exe);
 #endif
 
   boot1_offset += boot_offset;
@@ -470,6 +278,7 @@ static int bytes_main(int argc, char **argv,
     ba.collects_dir = extract_coldir();
     ba.config_dir = extract_configdir();
     ba.dll_dir = extract_dlldir();
+    ba.k_file = SELF_PATH_TO_BYTES(self_exe);
 
     ba.cs_compiled_subdir = CS_COMPILED_SUBDIR;
 
diff --git a/racket/src/cs/main.sps b/racket/src/cs/main.sps
index fd5333779a..7af4adbe3b 100644
--- a/racket/src/cs/main.sps
+++ b/racket/src/cs/main.sps
@@ -86,13 +86,13 @@
      (#%newline (#%current-error-port))
      (exit 1))
 
-   (define builtin-argc 10)
+   (define builtin-argc 11)
    (seq
     (unless (>= (length the-command-line-arguments) builtin-argc)
       (startup-error (string-append
 		      "expected `embedded-interactive-mode?`,"
                       " `exec-file`, `run-file`, `collects`, and `etc` paths"
-		      " plus `segment-offset`, `cs-compiled-subdir?`, `is-gui?`,"
+		      " plus `k-file`, `segment-offset`, `cs-compiled-subdir?`, `is-gui?`,"
 		      " `wm-is-gracket-or-x11-arg-count`, and `gracket-guid-or-x11-args`"
 		      " to start")))
     (set-exec-file! (->path (list-ref the-command-line-arguments/maybe-bytes 1)))
@@ -110,11 +110,14 @@
                         (map ->path (cdr s))))])))
    (define init-config-dir (->path (or (getenv-bytes "PLTCONFIGDIR")
                                        (list-ref the-command-line-arguments/maybe-bytes 4))))
-   (define segment-offset (#%string->number (list-ref the-command-line-arguments 5)))
-   (define cs-compiled-subdir? (string=? "true" (list-ref the-command-line-arguments 6)))
-   (define gracket? (string=? "true" (list-ref the-command-line-arguments 7)))
-   (define wm-is-gracket-or-x11-arg-count (string->number (list-ref the-command-line-arguments 8)))
-   (define gracket-guid-or-x11-args (list-ref the-command-line-arguments 9))
+   (define k-executable-path (let ([s (list-ref the-command-line-arguments/maybe-bytes 5)])
+                               (and (not (or (equal? s "") (equal? s '#vu8())))
+                                    s)))
+   (define segment-offset (#%string->number (list-ref the-command-line-arguments 6)))
+   (define cs-compiled-subdir? (string=? "true" (list-ref the-command-line-arguments 7)))
+   (define gracket? (string=? "true" (list-ref the-command-line-arguments 8)))
+   (define wm-is-gracket-or-x11-arg-count (string->number (list-ref the-command-line-arguments 9)))
+   (define gracket-guid-or-x11-args (list-ref the-command-line-arguments 10))
 
    (seq
     (when (eq? 'windows (system-type))
@@ -415,10 +418,11 @@
                           (let ([n (#%string->number s)])
                             (unless (exact-integer? n)
                               (startup-error "bad ~a: ~a" what s))
-                            (#%number->string (+ n segment-offset))))]
+                            (#%number->string (+ n (if f 0 segment-offset)))))]
                        [n (add-segment-offset n "starting offset")]
                        [m (add-segment-offset m "first ending offset")]
-                       [p (add-segment-offset p "second ending offset")])
+                       [p (add-segment-offset p "second ending offset")]
+                       [f (or f k-executable-path)])
                   (set! loads
                         (cons
                          (lambda ()
diff --git a/racket/src/start/config.inc b/racket/src/start/config.inc
index 3d10d19b76..69dcf83eeb 100644
--- a/racket/src/start/config.inc
+++ b/racket/src/start/config.inc
@@ -1,5 +1,36 @@
 /* This code fragment embeds strings in an executable that can be
-   updated with various Racket exe-manipulation tools. */
+   updated with various Racket exe-manipulation tools. 
+
+   Used by CS's "main.c" and BC's "cmdline.inc".
+
+   Functions that are "exported":
+
+      self_exe_t get_self_path(char *argv0);
+      void extract_built_in_arguments(const self_exe_t self_exe, 
+                                      char **_prog, char **_sprog,
+                                      int *_argc, char ***_argv);
+      char *SELF_PATH_TO_BYTES(self_exe_t)
+
+      char *extract_coldir();
+      char *extract_configdir();
+
+      long get_segment_offset(self_exe_t self); // added to `-k` arguments
+
+    Windows:
+      self_exe_t is wchar_t
+      wchar_t *extract_dlldir();
+      long find_resource_offset(const wchar_t *path, int id, long delta);
+      char *string_to_utf8(wchar_t *p);
+
+    Mac OS:
+      long find_mach_o_segment(const char *name, long *_len);
+
+    Unix:
+      int find_elf_section_offset(const char *filename,
+                                  const char *name,
+                                  int *_start, int *_end);
+
+*/
 
 #pragma GCC diagnostic ignored "-Wwrite-strings"
 
@@ -99,15 +130,19 @@ static int _configdir_offset = 17; /* Skip permanent tag */
 # define XFORM_OK_PLUS +
 #endif
 
-#ifdef OS_X
-# include <mach-o/getsect.h>
-# include <mach-o/dyld.h>
-# include <fcntl.h>
-#endif
-
 #ifdef DOS_FILE_SYSTEM
 # include <windows.h>
+#else
+# include <errno.h>
+# include <fcntl.h>
+# include <sys/types.h>
+# include <sys/uio.h>
+# include <unistd.h>
+#endif
 
+#include "self_exe.inc"
+
+#ifdef DOS_FILE_SYSTEM
 #ifndef DLL_RELATIVE_PATH
 # define DLL_RELATIVE_PATH L"lib"
 #endif
@@ -127,40 +162,13 @@ END_XFORM_SKIP;
 #endif
 
 #ifdef OS_X
-static long get_segment_offset()
+static long get_segment_offset(const char *me)
 {
-# if defined(__x86_64__) || defined(__arm64__)
-  const struct segment_command_64 *seg;
-# else
-  const struct segment_command *seg;
-#endif
-  seg = getsegbyname("__PLTSCHEME");
-  if (seg)
-    return seg->fileoff;
-  else
-    return 0;
+  return find_mach_o_segment("__PLTSCHEME", NULL);
 }
 #endif
 
 #ifdef DOS_FILE_SYSTEM
-wchar_t *get_self_executable_path() XFORM_SKIP_PROC
-{
-  wchar_t *path;
-  DWORD r, sz = 1024;
-
-  while (1) {
-    path = (wchar_t *)malloc(sz * sizeof(wchar_t));
-    r = GetModuleFileNameW(NULL, path, sz);
-    if ((r == sz)
-        && (GetLastError() == ERROR_INSUFFICIENT_BUFFER)) {
-      free(path);
-      sz = 2 * sz;
-    } else
-      break;
-  }
-
-  return path;
-}
 
 static DWORD find_by_id(HANDLE fd, DWORD rsrcs, DWORD pos, int id, long delta) XFORM_SKIP_PROC
 {
@@ -185,7 +193,7 @@ static DWORD find_by_id(HANDLE fd, DWORD rsrcs, DWORD pos, int id, long delta) X
   return 0;
 }
 
-static long find_resource_offset(wchar_t *path, int id, long delta) XFORM_SKIP_PROC
+static long find_resource_offset(const wchar_t *path, int id, long delta) XFORM_SKIP_PROC
 {
   /* Find the resource of type `id` */
   HANDLE fd;
@@ -258,14 +266,45 @@ static long find_resource_offset(wchar_t *path, int id, long delta) XFORM_SKIP_P
   }
 }
 
-static long get_segment_offset() XFORM_SKIP_PROC
+static long get_segment_offset(const wchar_t *me) XFORM_SKIP_PROC
 {
-  return find_resource_offset(get_self_executable_path(), 257, 0);
+  return find_resource_offset(me, 257, 0);
+}
+
+static char *string_to_utf8(wchar_t *p) XFORM_SKIP_PROC
+{
+  char *r;
+  int len;
+
+  len = WideCharToMultiByte(CP_UTF8, 0, p, -1, NULL, 0, NULL, NULL);
+  r = malloc(len);
+  len = WideCharToMultiByte(CP_UTF8, 0, p, -1, r, len, NULL, NULL);
+
+  return r;
+}
+
+# define SELF_PATH_TO_BYTES(s) string_to_utf8(s)
+
+#else
+
+# define SELF_PATH_TO_BYTES(s) s
+
+#endif
+
+#if !defined(OS_X) && !defined(DOS_FILE_SYSTEM)
+
+static long get_segment_offset(const char *me) XFORM_SKIP_PROC
+{
+  int start = 0, end = 0;
+
+  (void)find_elf_section_offset(me, ".rackprog", &start, &end);
+  
+  return start;
 }
 
 #endif
 
-static void extract_built_in_arguments(char **_prog, char **_sprog, int *_argc, char ***_argv)
+static void extract_built_in_arguments(const self_exe_t self_exe, char **_prog, char **_sprog, int *_argc, char ***_argv)
 {
   GC_CAN_IGNORE char *prog = *_prog;
   GC_CAN_IGNORE char *sprog = *_sprog;
@@ -321,9 +360,8 @@ static void extract_built_in_arguments(char **_prog, char **_sprog, int *_argc,
 	 the cmdline string is. It might be relative to the
 	 executable. */
       HANDLE fd;
-      wchar_t *path;
+      wchar_t *path = self_exe;
 
-      path = get_self_executable_path();
       fd = CreateFileW(path, GENERIC_READ,
 		       FILE_SHARE_READ | FILE_SHARE_WRITE,
 		       NULL,
@@ -337,7 +375,7 @@ static void extract_built_in_arguments(char **_prog, char **_sprog, int *_argc,
 	DWORD got;
 	start = *(long *)&scheme_cmdline_exe_hack[4];
 	len = *(long *)&scheme_cmdline_exe_hack[8];
-	start += get_segment_offset();
+	start += get_segment_offset(self_exe);
 	p = (unsigned char *)malloc(len);
 	SetFilePointer(fd, start, 0, FILE_BEGIN);
 	ReadFile(fd, p, len, &got, NULL);
@@ -386,14 +424,12 @@ static void extract_built_in_arguments(char **_prog, char **_sprog, int *_argc,
 		+ 4);
 	}
       }
-      free(path);
     }
-#endif
-#if defined(OS_X)
+#else
     if (scheme_cmdline_exe_hack[0] == '?') {
-      long fileoff, cmdoff, cmdlen;
+      long fileoff, cmdoff, cmdlen, need, got;
       int fd;
-      fileoff = get_segment_offset();
+      fileoff = get_segment_offset(self_exe);
 
       p = (unsigned char *)scheme_cmdline_exe_hack + 4;
       cmdoff = (p[0]
@@ -405,14 +441,22 @@ static void extract_built_in_arguments(char **_prog, char **_sprog, int *_argc,
                 + (((long)p[6]) << 16)
                 + (((long)p[7]) << 24));
       p = malloc(cmdlen);
-      
-      fd = open(_dyld_get_image_name(0), O_RDONLY);
+
+      fd = open(self_exe, O_RDONLY);
       lseek(fd, fileoff + cmdoff, 0);
-      read(fd, p, cmdlen);
+
+      for (need = cmdlen; need > 0; need -= got) {
+	got = read(fd, p + (cmdlen - need), need);
+	if (got == -1) {
+	  got = 0;
+	  if (errno != EINTR)
+	    break;
+	}
+      }
       close(fd);
     }
 #endif
-     
+
     if (!p)
       p = (unsigned char *)scheme_cmdline_exe_hack + 1;
 
@@ -465,7 +509,3 @@ static char *extract_configdir()
 {
   return scheme_configdir XFORM_OK_PLUS _configdir_offset;
 }
-
-#if !defined(OS_X) && !defined(DOS_FILE_SYSTEM)
-# define NO_GET_SEGMENT_OFFSET
-#endif
diff --git a/racket/src/start/embedded_dll.inc b/racket/src/start/embedded_dll.inc
index 52ccbeed8d..b8b4d5f1cd 100644
--- a/racket/src/start/embedded_dll.inc
+++ b/racket/src/start/embedded_dll.inc
@@ -20,7 +20,7 @@ static HANDLE open_self()
   wchar_t *path;
   HANDLE fd;
   
-  path = get_self_executable_path();
+  path = get_self_path(NULL);
 
   fd = CreateFileW(path, GENERIC_READ,
 		   FILE_SHARE_READ | FILE_SHARE_WRITE,
@@ -38,7 +38,7 @@ static void parse_embedded_dlls()
 {
   long rsrc_pos;
 
-  rsrc_pos = find_resource_offset(get_self_executable_path(), 258, 0);
+  rsrc_pos = find_resource_offset(get_self_path(NULL), 258, 0);
   if (rsrc_pos) {
     HANDLE fd = open_self();
     
diff --git a/racket/src/start/self_exe.inc b/racket/src/start/self_exe.inc
new file mode 100644
index 0000000000..6546b1f0dd
--- /dev/null
+++ b/racket/src/start/self_exe.inc
@@ -0,0 +1,368 @@
+/* Used by "ustart.c" and "config.inc".
+
+   Defines self_exe_t get_self_path(char *exec_file),
+   which takes argv[0] and returns an improved representation of
+   the containing executable. At worst, on Unix, uses `PATH` to
+   convert `exec_file` into a path.
+
+   On Mac (even XonX), `find_mach_o_segment` is also defined.
+
+   On Unix (not Mac OS, not even XonX), `find_elf_section`
+   is also defined. 
+
+   If USE_EXE_LOOKUP_VIA_PATH, also: `lookup_exe_via_path`,
+   `path_append`, and `do_path_append`.
+*/
+
+#define USE_GENERIC_GET_SELF_PATH
+
+#ifdef DOS_FILE_SYSTEM
+typedef wchar_t *self_exe_t;
+#else
+typedef char *self_exe_t;
+#endif
+
+#if defined(__linux__)
+# include <errno.h>
+# include <unistd.h>
+static char *get_self_path(char *exec_file)
+{
+  char buf[256], *s = buf;
+  ssize_t len, blen = sizeof(buf);
+
+  while (1) {
+    len = readlink("/proc/self/exe", s, blen-1);
+    if (len == (blen-1)) {
+      if (s != buf) free(s);
+      blen *= 2;
+      s = malloc(blen);
+    } else if (len < 0) {
+      fprintf(stderr, "failed to get self (%d)\n", errno);
+      exit(1);
+    } else
+      break;
+  }
+  buf[len] = 0;
+  return strdup(buf);
+}
+# undef USE_GENERIC_GET_SELF_PATH
+#endif
+
+#if defined(__FreeBSD__) || defined(__NetBSD__)
+# include <sys/sysctl.h>
+# include <errno.h>
+static char *get_self_path(char *exec_file)
+{
+  int mib[4];
+  char *s;
+  size_t len;
+  int r;
+
+  mib[0] = CTL_KERN;
+#if defined(__NetBSD__)
+  mib[1] = KERN_PROC_ARGS;
+  mib[2] = getpid();
+  mib[3] = KERN_PROC_PATHNAME;
+#else
+  mib[1] = KERN_PROC;
+  mib[2] = KERN_PROC_PATHNAME;
+  mib[3] = -1;
+#endif
+
+  r = sysctl(mib, 4, NULL, &len, NULL, 0);
+  if (r < 0) {
+      fprintf(stderr, "failed to get self (%d)\n", errno);
+      exit(1);
+  }
+  s = malloc(len);
+  r = sysctl(mib, 4, s, &len, NULL, 0);
+  if (r < 0) {
+      fprintf(stderr, "failed to get self (%d)\n", errno);
+      exit(1);
+  }
+  return s;
+}
+# undef USE_GENERIC_GET_SELF_PATH
+#endif
+
+#if defined(__APPLE__) && defined(__MACH__)
+# include <mach-o/getsect.h>
+# include <mach-o/dyld.h>
+static char *get_self_path(char *exec_file)
+{
+  char buf[1024], *s;
+  uint32_t size = sizeof(buf);
+  int r;
+  
+  r = _NSGetExecutablePath(buf, &size);
+  if (!r)
+    return strdup(buf);
+  else {
+    s = malloc(size);
+    r = _NSGetExecutablePath(s, &size);
+    if (!r)
+      return s;
+    fprintf(stderr, "failed to get self\n");
+    exit(1);
+  }
+}
+# undef USE_GENERIC_GET_SELF_PATH
+
+static long find_mach_o_segment(const char *name, long *_len)
+{
+# if defined(__x86_64__) || defined(__arm64__)
+  const struct segment_command_64 *seg;
+# else
+  const struct segment_command *seg;
+#endif
+  seg = getsegbyname(name);
+  if (seg) {
+    if (_len)
+      *_len = seg->filesize;
+    return seg->fileoff;
+  } else
+    return 0;
+}
+#endif
+
+#ifdef DOS_FILE_SYSTEM
+/* used outside this file: */
+wchar_t *get_self_path(char *exec_file) XFORM_SKIP_PROC
+{
+  wchar_t *path;
+  DWORD r, sz = 1024;
+
+  while (1) {
+    path = (wchar_t *)malloc(sz * sizeof(wchar_t));
+    r = GetModuleFileNameW(NULL, path, sz);
+    if ((r == sz)
+        && (GetLastError() == ERROR_INSUFFICIENT_BUFFER)) {
+      free(path);
+      sz = 2 * sz;
+    } else
+      break;
+  }
+
+  return path;
+}
+# undef USE_GENERIC_GET_SELF_PATH
+#endif
+
+#if defined(USE_GENERIC_GET_SELF_PATH) || defined(USE_EXE_LOOKUP_VIA_PATH)
+
+/* Get executable path via argv[0] and the `PATH` environment variable */
+
+static int has_slash(char *s) XFORM_SKIP_PROC
+{
+  while (*s) {
+    if (s[0] == '/')
+      return 1;
+    s++;
+  }
+  return 0;
+}
+
+static char *do_path_append(char *s1, int l1, char *s2) XFORM_SKIP_PROC
+{
+  int l2;
+  char *s;
+
+  l2 = strlen(s2);
+
+  s  = (char *)malloc(l1 + l2 + 2);
+
+  memcpy(s, s1, l1);
+  if (s[l1 - 1] != '/') {
+    s[l1++] = '/';
+  }
+
+  memcpy(s + l1, s2, l2);
+  s[l1 + l2] = 0;
+
+  return s;
+}
+
+static char *path_append(char *s1, char *s2) XFORM_SKIP_PROC
+{
+  return do_path_append(s1, strlen(s1), s2);
+}
+
+static char *copy_string(char *s1) XFORM_SKIP_PROC
+{
+  int l1;
+  char *s;
+
+  if (!s1) return NULL;
+
+  l1 = strlen(s1);
+
+  s  = (char *)malloc(l1 + 1);
+
+  memcpy(s, s1, l1 + 1);
+
+  return s;
+}
+
+static int executable_exists(char *path) XFORM_SKIP_PROC
+{
+  return (access(path, X_OK) == 0);
+}
+
+static char *lookup_exe_via_path(char *exec_file) XFORM_SKIP_PROC
+{
+  if (exec_file[0] == '/') {
+    /* Absolute path */
+    return exec_file;
+  } else if (has_slash(exec_file)) {
+    /* Relative path with a directory: */
+    char *buf;
+    long buflen = 4096;
+    buf = (char *)malloc(buflen);
+    return path_append(getcwd(buf, buflen), exec_file);
+  } else {
+    /* We have to find the executable by searching PATH: */
+    char *path = copy_string(getenv("PATH")), *p, *m;
+    int more;
+
+    if (!path) {
+      path = "";
+    }
+
+    while (1) {
+      /* Try each element of path: */
+      for (p = path; *p && (*p != ':'); p++) { }
+      if (*p) {
+	*p = 0;
+	more = 1;
+      } else
+	more = 0;
+
+      if (!*path)
+	break;
+
+      m = path_append(path, exec_file);
+
+      if (executable_exists(m)) {
+	if (m[0] != '/')
+	  m = path_append(getcwd(NULL, 0), m);
+	return m;
+      }
+      free(m);
+
+      if (more)
+	path = p + 1;
+      else
+	break;
+    }
+
+    return exec_file;
+  }
+}
+#endif
+
+#ifdef USE_GENERIC_GET_SELF_PATH
+static char *get_self_path(char *exec_file)
+{
+  return lookup_exe_via_path(exec_file);
+}
+#endif
+
+#if !defined(OS_X) && !defined(DOS_FILE_SYSTEM)
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+typedef unsigned short ELF__Half;
+typedef unsigned int ELF__Word;
+typedef unsigned long ELF__Xword;
+typedef unsigned long ELF__Addr;
+typedef unsigned long ELF__Off;
+
+typedef struct { 
+  unsigned char e_ident[16]; 
+  ELF__Half e_type; 
+  ELF__Half e_machine; 
+  ELF__Word e_version; 
+  ELF__Addr e_entry; 
+  ELF__Off e_phoff; 
+  ELF__Off e_shoff; 
+  ELF__Word e_flags; 
+  ELF__Half e_ehsize; 
+  ELF__Half e_phentsize; 
+  ELF__Half e_phnum; 
+  ELF__Half e_shentsize; 
+  ELF__Half e_shnum;
+  ELF__Half e_shstrndx;
+} ELF__Header;
+
+typedef struct
+{
+  ELF__Word sh_name;
+  ELF__Word sh_type;
+  ELF__Xword sh_flags;
+  ELF__Addr sh_addr;
+  ELF__Off sh_offset;
+  ELF__Xword sh_size;
+  ELF__Word sh_link;
+  ELF__Word sh_info;
+  ELF__Xword sh_addralign;
+  ELF__Xword sh_entsize;
+} Elf__Shdr;
+
+static int find_elf_section_offset(const char *filename,
+                                   const char *name,
+                                   int *_start, int *_end) XFORM_SKIP_PROC
+{
+  int fd, i;
+  ELF__Header e;
+  Elf__Shdr s;
+  char *strs;
+
+  fd = open(filename, O_RDONLY, 0);
+  if (fd == -1) return 0;
+
+  if (read(fd, &e, sizeof(e)) == sizeof(e)) {
+    if ((e.e_ident[0] == 0x7F)
+	&& (e.e_ident[1] == 'E')
+	&& (e.e_ident[2] == 'L')
+	&& (e.e_ident[3] == 'F')) {
+
+      lseek(fd, e.e_shoff + (e.e_shstrndx * e.e_shentsize), SEEK_SET);
+      if (read(fd, &s, sizeof(s)) != sizeof(s)) {
+	close(fd);
+	return 0;
+      }
+
+      strs = (char *)malloc(s.sh_size);
+      lseek(fd, s.sh_offset, SEEK_SET);
+      if (read(fd, strs, s.sh_size) != s.sh_size) {
+	close(fd);
+        free(strs);
+	return 0;
+      }
+
+      for (i = 0; i < e.e_shnum; i++) {
+	lseek(fd, e.e_shoff + (i * e.e_shentsize), SEEK_SET);
+	if (read(fd, &s, sizeof(s)) != sizeof(s)) {
+	  close(fd);
+	  return 0;
+	}
+	if (!strcmp(strs + s.sh_name, name)) {
+	  *_start = s.sh_offset;
+          *_end = s.sh_offset + s.sh_size;
+	  close(fd);
+          free(strs);
+	  return 1;
+	}
+      }
+
+      free(strs);
+    }
+  }
+
+  close(fd);
+  return 0;
+}
+
+#endif
diff --git a/racket/src/start/unix_self.inc b/racket/src/start/unix_self.inc
deleted file mode 100644
index b2ee738eba..0000000000
--- a/racket/src/start/unix_self.inc
+++ /dev/null
@@ -1,86 +0,0 @@
-#define USE_GENERIC_GET_SELF_PATH
-
-#if defined(__linux__)
-# include <errno.h>
-static char *get_self_path(char *exec_file)
-{
-  char buf[256], *s = buf;
-  ssize_t len, blen = sizeof(buf);
-
-  while (1) {
-    len = readlink("/proc/self/exe", s, blen-1);
-    if (len == (blen-1)) {
-      if (s != buf) free(s);
-      blen *= 2;
-      s = malloc(blen);
-    } else if (len < 0) {
-      fprintf(stderr, "failed to get self (%d)\n", errno);
-      exit(1);
-    } else
-      break;
-  }
-  buf[len] = 0;
-  return strdup(buf);
-}
-# undef USE_GENERIC_GET_SELF_PATH
-#endif
-
-#if defined(__FreeBSD__) || defined(__NetBSD__)
-# include <sys/sysctl.h>
-# include <errno.h>
-static char *get_self_path(char *exec_file)
-{
-  int mib[4];
-  char *s;
-  size_t len;
-  int r;
-
-  mib[0] = CTL_KERN;
-#if defined(__NetBSD__)
-  mib[1] = KERN_PROC_ARGS;
-  mib[2] = getpid();
-  mib[3] = KERN_PROC_PATHNAME;
-#else
-  mib[1] = KERN_PROC;
-  mib[2] = KERN_PROC_PATHNAME;
-  mib[3] = -1;
-#endif
-
-  r = sysctl(mib, 4, NULL, &len, NULL, 0);
-  if (r < 0) {
-      fprintf(stderr, "failed to get self (%d)\n", errno);
-      exit(1);
-  }
-  s = malloc(len);
-  r = sysctl(mib, 4, s, &len, NULL, 0);
-  if (r < 0) {
-      fprintf(stderr, "failed to get self (%d)\n", errno);
-      exit(1);
-  }
-  return s;
-}
-# undef USE_GENERIC_GET_SELF_PATH
-#endif
-
-#if defined(__APPLE__) && defined(__MACH__)
-# include <mach-o/dyld.h>
-static char *get_self_path(char *exec_file)
-{
-  char buf[1024], *s;
-  uint32_t size = sizeof(buf);
-  int r;
-  
-  r = _NSGetExecutablePath(buf, &size);
-  if (!r)
-    return strdup(buf);
-  else {
-    s = malloc(size);
-    r = _NSGetExecutablePath(s, &size);
-    if (!r)
-      return s;
-    fprintf(stderr, "failed to get self\n");
-    exit(1);
-  }
-}
-# undef USE_GENERIC_GET_SELF_PATH
-#endif
diff --git a/racket/src/start/ustart.c b/racket/src/start/ustart.c
index 1dc24888c6..403850bc1e 100644
--- a/racket/src/start/ustart.c
+++ b/racket/src/start/ustart.c
@@ -95,6 +95,10 @@ char * volatile _configdir = "coNFIg dIRECTORy:" /* <- this tag stays, so we can
                        "****************************************************************";
 static int _configdir_offset = 17; /* Skip permanent tag */
 
+#define XFORM_SKIP_PROC /* empty */
+#define USE_EXE_LOOKUP_VIA_PATH
+#include "self_exe.inc"
+
 typedef struct {
   char *flag;
   int arg_count;
@@ -174,68 +178,12 @@ static char *string_append(char *s1, char *s2)
   return s;
 }
 
-static char *copy_string(char *s1)
-{
-  int l1;
-  char *s;
-
-  if (!s1) return NULL;
-
-  l1 = strlen(s1);
-
-  s  = (char *)malloc(l1 + 1);
-
-  memcpy(s, s1, l1 + 1);
-
-  return s;
-}
-
-static char *do_path_append(char *s1, int l1, char *s2)
-{
-  int l2;
-  char *s;
-
-  l2 = strlen(s2);
-
-  s  = (char *)malloc(l1 + l2 + 2);
-
-  memcpy(s, s1, l1);
-  if (s[l1 - 1] != '/') {
-    s[l1++] = '/';
-  }
-
-  memcpy(s + l1, s2, l2);
-  s[l1 + l2] = 0;
-
-  return s;
-}
-
-static char *path_append(char *s1, char *s2)
-{
-  return do_path_append(s1, strlen(s1), s2);
-}
-
-static int executable_exists(char *path)
-{
-  return (access(path, X_OK) == 0);
-}
-
 static int as_int(char *_c)
 {
   unsigned char *c = (unsigned char *)_c;
   return c[0] | ((int)c[1] << 8) | ((int)c[2] << 16)  | ((int)c[3] << 24);
 }
 
-static int has_slash(char *s)
-{
-  while (*s) {
-    if (s[0] == '/')
-      return 1;
-    s++;
-  }
-  return 0;
-}
-
 char *absolutize(char *p, char *d)
 {
   int l1;
@@ -262,107 +210,30 @@ static char *next_string(char *s)
   return s + strlen(s) + 1;
 }
 
-#include "unix_self.inc"
-
-#ifdef USE_GENERIC_GET_SELF_PATH
-static char *adjust_self_reference(char *me)
+static int try_section_shift(const char *me, int *_start, int *_decl_end, int *_prog_end, int *_end)
 {
-  return me;
-}
+  int start = 0, end = 0;
+  int is_prog;
+  
+#ifdef OS_X
+  {
+    long len = 0;
+    start = find_mach_o_segment("__PLTSCHEME", &len);
+    end = start + len;
+    is_prog = 1;
+  }
 #else
-static char *adjust_self_reference(char *me)
-{
-  return get_self_path(me);
-}
+  is_prog = find_elf_section_offset(me, ".rackprog", &start, &end);
 #endif
 
-typedef unsigned short ELF__Half;
-typedef unsigned int ELF__Word;
-typedef unsigned long ELF__Xword;
-typedef unsigned long ELF__Addr;
-typedef unsigned long ELF__Off;
-
-typedef struct { 
-  unsigned char e_ident[16]; 
-  ELF__Half e_type; 
-  ELF__Half e_machine; 
-  ELF__Word e_version; 
-  ELF__Addr e_entry; 
-  ELF__Off e_phoff; 
-  ELF__Off e_shoff; 
-  ELF__Word e_flags; 
-  ELF__Half e_ehsize; 
-  ELF__Half e_phentsize; 
-  ELF__Half e_phnum; 
-  ELF__Half e_shentsize; 
-  ELF__Half e_shnum;
-  ELF__Half e_shstrndx;
-} ELF__Header;
-
-typedef struct
-{
-  ELF__Word sh_name;
-  ELF__Word sh_type;
-  ELF__Xword sh_flags;
-  ELF__Addr sh_addr;
-  ELF__Off sh_offset;
-  ELF__Xword sh_size;
-  ELF__Word sh_link;
-  ELF__Word sh_info;
-  ELF__Xword sh_addralign;
-  ELF__Xword sh_entsize;
-} Elf__Shdr;
-
-static int try_elf_section(const char *me, int *_start, int *_decl_end, int *_prog_end, int *_end)
-{
-  int fd, i;
-  ELF__Header e;
-  Elf__Shdr s;
-  char *strs;
-
-  fd = open(me, O_RDONLY, 0);
-  if (fd == -1) return 0;
-
-  if (read(fd, &e, sizeof(e)) == sizeof(e)) {
-    if ((e.e_ident[0] == 0x7F)
-	&& (e.e_ident[1] == 'E')
-	&& (e.e_ident[2] == 'L')
-	&& (e.e_ident[3] == 'F')) {
-
-      lseek(fd, e.e_shoff + (e.e_shstrndx * e.e_shentsize), SEEK_SET);
-      if (read(fd, &s, sizeof(s)) != sizeof(s)) {
-	close(fd);
-	return 0;
-      }
-
-      strs = (char *)malloc(s.sh_size);
-      lseek(fd, s.sh_offset, SEEK_SET);
-      if (read(fd, strs, s.sh_size) != s.sh_size) {
-	close(fd);
-	return 0;
-      }
-
-      for (i = 0; i < e.e_shnum; i++) {
-	lseek(fd, e.e_shoff + (i * e.e_shentsize), SEEK_SET);
-	if (read(fd, &s, sizeof(s)) != sizeof(s)) {
-	  close(fd);
-	  return 0;
-	}
-	if (!strcmp(strs + s.sh_name, ".rackcmdl")
-	    || !strcmp(strs + s.sh_name, ".rackprog")) {
-	  *_decl_end = (*_decl_end - *_start) + s.sh_offset;
-	  *_prog_end = (*_prog_end - *_start) + s.sh_offset;
-	  *_start = s.sh_offset;
-	  *_end = s.sh_offset + s.sh_size;
-	  close(fd);
-	  return !strcmp(strs + s.sh_name, ".rackprog");
-	}
-      }
-    }
+  if (start != 0) {
+    *_decl_end = (*_decl_end - *_start) + start;
+    *_prog_end = (*_prog_end - *_start) + start;
+    *_start = start;
+    *_end = end;
   }
 
-  close(fd);
-  return 0;
+  return is_prog;
 }
 
 int main(int argc, char **argv)
@@ -379,52 +250,7 @@ int main(int argc, char **argv)
     return 1;
   }
 
-  if (me[0] == '/') {
-    /* Absolute path */
-  } else if (has_slash(me)) {
-    /* Relative path with a directory: */
-    char *buf;
-    long buflen = 4096;
-    buf = (char *)malloc(buflen);
-    me = path_append(getcwd(buf, buflen), me);
-    free(buf);
-  } else {
-    /* We have to find the executable by searching PATH: */
-    char *path = copy_string(getenv("PATH")), *p, *m;
-    int more;
-
-    if (!path) {
-      path = "";
-    }
-
-    while (1) {
-      /* Try each element of path: */
-      for (p = path; *p && (*p != ':'); p++) { }
-      if (*p) {
-	*p = 0;
-	more = 1;
-      } else
-	more = 0;
-
-      if (!*path)
-	break;
-
-      m = path_append(path, me);
-
-      if (executable_exists(m)) {
-	if (m[0] != '/')
-	  m = path_append(getcwd(NULL, 0), m);
-	me = m;
-	break;
-      }
-      free(m);
-
-      if (more)
-	path = p + 1;
-      else
-	break;
-    }
-  }
+  me = lookup_exe_via_path(me);
   
   /* me is now an absolute path to the binary */
 
@@ -451,7 +277,7 @@ int main(int argc, char **argv)
   /* use `me` for `-k`, unless we have a way to more directly get the
      executable file that contains embedded code; if we do, then
      argv[0] doesn't have to match the executable */
-  embedding_me = adjust_self_reference(me);
+  embedding_me = get_self_path(me);
 
   start = as_int(config + 8);
   decl_end = as_int(config + 12);
@@ -460,7 +286,7 @@ int main(int argc, char **argv)
   count = as_int(config + 24);
   x11 = as_int(config + 28);
 
-  fix_argv = try_elf_section(embedding_me, &start, &decl_end, &prog_end, &end);
+  try_section_shift(embedding_me, &start, &decl_end, &prog_end, &end);
 
   {
     int offset, len;
@@ -566,13 +392,11 @@ int main(int argc, char **argv)
   new_argv[argpos++] = "-G";
   new_argv[argpos++] = absolutize(_configdir + _configdir_offset, me);
 
-  if (fix_argv) {
-    /* next four args are "-k" and numbers; leave room to insert the
-       filename in place of "-k", and fix the numbers to match start,
-       decl_end, and prog_end */
-    new_argv[argpos++] = "-Y";
-    fix_argv = argpos;
-  }
+  /* next four args are "-k" and numbers; leave room to insert the
+     filename in place of "-k", and fix the numbers to match start,
+     decl_end, and prog_end */
+  new_argv[argpos++] = "-Y";
+  fix_argv = argpos;
 
   /* Add built-in flags: */
   while (count--) {
diff --git a/racket/src/worksp/.gitignore b/racket/src/worksp/.gitignore
index bedb80ed2a..47ee5b5912 100644
--- a/racket/src/worksp/.gitignore
+++ b/racket/src/worksp/.gitignore
@@ -42,3 +42,6 @@ cstartup.exe
 /liblz4.dll
 /liblz4.lib
 /liblz4.exp
+/liblz4mt.dll
+/liblz4mt.lib
+/liblz4mt.exp