diff --git a/Include/Python.h b/Include/Python.h
index 61f8865..76b9503 100644
--- a/Include/Python.h
+++ b/Include/Python.h
@@ -6,6 +6,7 @@
 
 #include "patchlevel.h"
 #include "pyconfig.h"
+#include "pymacconfig.h"
 
 #include <limits.h>
 
diff --git a/Include/pymacconfig.h b/Include/pymacconfig.h
new file mode 100644
index 0000000..e864e72
--- /dev/null
+++ b/Include/pymacconfig.h
@@ -0,0 +1,59 @@
+#ifndef PYMACCONFIG_H
+#define PYMACCONFIG_H
+     /*
+      * This file moves some of the autoconf magic to compile-time
+      * when building on MacOSX. This is needed for building 4-way
+      * universal binaries and for 64-bit universal binaries because
+      * the values redefined below aren't configure-time constant but 
+      * only compile-time constant in these scenarios.
+      */
+
+#if defined(__APPLE__)
+
+# undef SIZEOF_LONG
+# undef SIZEOF_PTHREAD_T
+# undef SIZEOF_SIZE_T
+# undef SIZEOF_TIME_T
+# undef SIZEOF_VOID_P
+
+#    undef VA_LIST_IS_ARRAY
+#    if defined(__LP64__) && defined(__x86_64__)
+#        define VA_LIST_IS_ARRAY 1
+#    endif
+
+#    undef HAVE_LARGEFILE_SUPPORT
+#    ifndef __LP64__
+#         define HAVE_LARGEFILE_SUPPORT 1
+#    endif
+
+#    undef SIZEOF_LONG
+#    ifdef __LP64__
+#        define SIZEOF_LONG 		8
+#        define SIZEOF_PTHREAD_T 	8
+#        define SIZEOF_SIZE_T 		8
+#        define SIZEOF_TIME_T 		8
+#        define SIZEOF_VOID_P 		8
+#    else
+#        define SIZEOF_LONG 		4
+#        define SIZEOF_PTHREAD_T 	4
+#        define SIZEOF_SIZE_T 		4
+#        define SIZEOF_TIME_T 		4
+#        define SIZEOF_VOID_P 		4
+#    endif
+
+#    if defined(__LP64__)
+	 /* MacOSX 10.4 (the first release to suppport 64-bit code
+	  * at all) only supports 64-bit in the UNIX layer. 
+	  * Therefore surpress the toolbox-glue in 64-bit mode.
+	  */
+
+	/* In 64-bit mode setpgrp always has no argments, in 32-bit
+	 * mode that depends on the compilation environment
+	 */
+#	undef SETPGRP_HAVE_ARG
+
+#    endif
+
+#endif /* defined(_APPLE__) */
+
+#endif /* PYMACCONFIG_H */
diff --git a/Lib/distutils/sysconfig.py b/Lib/distutils/sysconfig.py
index d2b2c9a..3a120dd 100644
--- a/Lib/distutils/sysconfig.py
+++ b/Lib/distutils/sysconfig.py
@@ -516,6 +516,26 @@
                     flags = re.sub('-isysroot [^ \t]*', ' ', flags)
                     _config_vars[key] = flags
 
+            else:
+
+                # Allow the user to override the architecture flags using
+                # an environment variable.
+                # NOTE: This name was introduced by Apple in OSX 10.5 and
+                # is used by several scripting languages distributed with
+                # that OS release.
+
+                if 'ARCHFLAGS' in os.environ:
+                    arch = os.environ['ARCHFLAGS']
+                    for key in ('LDFLAGS', 'BASECFLAGS',
+                        # a number of derived variables. These need to be
+                        # patched up as well.
+                        'CFLAGS', 'PY_CFLAGS', 'BLDSHARED'):
+
+                        flags = _config_vars[key]
+                        flags = re.sub('-arch\s+\w+\s', ' ', flags)
+                        flags = flags + ' ' + arch
+                        _config_vars[key] = flags
+
     if args:
         vals = []
         for name in args:
diff --git a/Lib/distutils/unixccompiler.py b/Lib/distutils/unixccompiler.py
index 25a042d..87ce921 100644
--- a/Lib/distutils/unixccompiler.py
+++ b/Lib/distutils/unixccompiler.py
@@ -63,7 +63,7 @@
         stripArch = '-arch' in cc_args
         stripSysroot = '-isysroot' in cc_args
 
-    if stripArch:
+    if stripArch or 'ARCHFLAGS' in os.environ:
         while True:
             try:
                 index = compiler_so.index('-arch')
@@ -72,6 +72,12 @@
             except ValueError:
                 break
 
+    if 'ARCHFLAGS' in os.environ and not stripArch:
+        # User specified different -arch flags in the environ,
+        # see also distutils.sysconfig
+        compiler_so = compiler_so + ' ' + os.environ['ARCHFLAGS']
+
+
     if stripSysroot:
         try:
             index = compiler_so.index('-isysroot')
diff --git a/Lib/distutils/util.py b/Lib/distutils/util.py
index 72039a7..76798b9 100644
--- a/Lib/distutils/util.py
+++ b/Lib/distutils/util.py
@@ -124,12 +124,19 @@
             osname = "macosx"
 
 
-            if (release + '.') < '10.4.' and \
-                    get_config_vars().get('UNIVERSALSDK', '').strip():
+            if (release + '.') >= '10.4.' and \
+                    '-arch' in get_config_vars().get('CFLAGS', '').strip():
                 # The universal build will build fat binaries, but not on
                 # systems before 10.4
+                #
+                # Try to detect 4-way universal builds, those have machine-type
+                # 'universal' instead of 'fat'.
+
                 machine = 'fat'
 
+                if '-arch x86_64' in get_config_vars().get('CFLAGS'):
+                    machine = 'universal'
+
             elif machine in ('PowerPC', 'Power_Macintosh'):
                 # Pick a sane name for the PPC architecture.
                 machine = 'ppc'
diff --git a/Lib/test/test_macos.py b/Lib/test/test_macos.py
new file mode 100644
index 0000000..e65b174
--- /dev/null
+++ b/Lib/test/test_macos.py
@@ -0,0 +1,43 @@
+import unittest
+import MacOS
+import Carbon.File
+from test import test_support
+import os
+
+TESTFN2 = test_support.TESTFN + '2'
+
+class TestMacOS(unittest.TestCase):
+
+    def testOpenRF(self):
+        try:
+            fp = open(test_support.TESTFN, 'w')
+            fp.write('hello world\n')
+            fp.close()
+
+            rfp = MacOS.openrf(test_support.TESTFN, '*wb')
+            rfp.write('goodbye world\n')
+            rfp.close()
+
+
+            fp = open(test_support.TESTFN, 'r')
+            data = fp.read()
+            fp.close()
+            self.assertEquals(data, 'hello world\n')
+
+            rfp = MacOS.openrf(test_support.TESTFN, '*rb')
+            data = rfp.read(100)
+            data2 = rfp.read(100)
+            rfp.close()
+            self.assertEquals(data, 'goodbye world\n')
+            self.assertEquals(data2, '')
+
+
+        finally:
+            os.unlink(test_support.TESTFN)
+
+def test_main():
+    test_support.run_unittest(TestMacOS)
+
+
+if __name__ == '__main__':
+    test_main()
diff --git a/Mac/IDLE/idlemain.py b/Mac/IDLE/idlemain.py
index aa75d4c..9b52738 100644
--- a/Mac/IDLE/idlemain.py
+++ b/Mac/IDLE/idlemain.py
@@ -13,7 +13,10 @@
 # Make sure sys.executable points to the python interpreter inside the
 # framework, instead of at the helper executable inside the application
 # bundle (the latter works, but doesn't allow access to the window server)
-sys.executable = os.path.join(sys.prefix, 'bin', 'python')
+if sys.executable.endswith('-32'):
+    sys.executable = os.path.join(sys.prefix, 'bin', 'python-32')
+else:
+    sys.executable = os.path.join(sys.prefix, 'bin', 'python')
 
 # Look for the -psn argument that the launcher adds and remove it, it will
 # only confuse the IDLE startup code.
diff --git a/Mac/Makefile.in b/Mac/Makefile.in
index 8cabb28..d12adcc 100644
--- a/Mac/Makefile.in
+++ b/Mac/Makefile.in
@@ -48,12 +48,42 @@
 installapps: install_PythonLauncher install_IDLE checkapplepython install_pythonw \
 	install_versionedtools
 
+installapps4way: install_Python4way install_BuildApplet install_PythonLauncher install_IDLE install_pythonw4way install_versionedtools
+
+
 install_pythonw: pythonw
 	$(INSTALL_PROGRAM) $(STRIPFLAG) pythonw "$(DESTDIR)$(prefix)/bin/pythonw$(VERSION)"
 	$(INSTALL_PROGRAM) $(STRIPFLAG) pythonw "$(DESTDIR)$(prefix)/bin/python$(VERSION)"
 	ln -sf python$(VERSION) "$(DESTDIR)$(prefix)/bin/python"
 	ln -sf pythonw$(VERSION) "$(DESTDIR)$(prefix)/bin/pythonw"
 
+
+# Install 3 variants of python/pythonw: 
+# 	- 32-bit (i386 and ppc)
+# 	- 64-bit (x86_64 and ppc64)
+# 	- all    (all four architectures)
+# 	- Make 'python' and 'pythonw' aliases for the 32-bit variant
+install_pythonw4way: pythonw-32 pythonw-64 pythonw
+	$(INSTALL_PROGRAM) $(STRIPFLAG) pythonw-64 "$(DESTDIR)$(prefix)/bin/pythonw$(VERSION)-64"
+	$(INSTALL_PROGRAM) $(STRIPFLAG) pythonw-64 "$(DESTDIR)$(prefix)/bin/python$(VERSION)-64"
+	ln -sf python$(VERSION)-64 "$(DESTDIR)$(prefix)/bin/python-64"
+	ln -sf pythonw$(VERSION)-64 "$(DESTDIR)$(prefix)/bin/pythonw-64"
+
+	$(INSTALL_PROGRAM) $(STRIPFLAG) pythonw-32 "$(DESTDIR)$(prefix)/bin/pythonw$(VERSION)-32"
+	$(INSTALL_PROGRAM) $(STRIPFLAG) pythonw-32 "$(DESTDIR)$(prefix)/bin/python$(VERSION)-32"
+	ln -sf python$(VERSION)-32 "$(DESTDIR)$(prefix)/bin/python-32"
+	ln -sf pythonw$(VERSION)-32 "$(DESTDIR)$(prefix)/bin/pythonw-32"
+
+	$(INSTALL_PROGRAM) $(STRIPFLAG) pythonw "$(DESTDIR)$(prefix)/bin/pythonw$(VERSION)-all"
+	$(INSTALL_PROGRAM) $(STRIPFLAG) pythonw "$(DESTDIR)$(prefix)/bin/python$(VERSION)-all"
+	ln -sf python$(VERSION)-all "$(DESTDIR)$(prefix)/bin/python-all"
+	ln -sf pythonw$(VERSION)-all "$(DESTDIR)$(prefix)/bin/pythonw-all"
+
+	ln -sf pythonw$(VERSION)-32	"$(DESTDIR)$(prefix)/bin/pythonw$(VERSION)"
+	ln -sf python$(VERSION)-32	"$(DESTDIR)$(prefix)/bin/python$(VERSION)"
+	ln -sf pythonw$(VERSION)-32	"$(DESTDIR)$(prefix)/bin/pythonw"
+	ln -sf python$(VERSION)-32	"$(DESTDIR)$(prefix)/bin/python"
+
 #
 # Install unix tools in /usr/local/bin. These are just aliases for the 
 # actual installation inside the framework.
@@ -64,11 +94,16 @@
 	fi
 	for fn in python pythonw idle pydoc python-config smtpd.py   \
 		  python$(VERSION) pythonw$(VERSION) idle$(VERSION) \
-		  pydoc$(VERSION) python-config$(VERSION) smtpd$(VERSION).py ;\
+		  pydoc$(VERSION) python$(VERSION)-config smtpd$(VERSION).py ;\
 	do \
 		ln -fs "$(prefix)/bin/$${fn}" "$(DESTDIR)$(FRAMEWORKUNIXTOOLSPREFIX)/bin/$${fn}" ;\
 	done
 
+
+# TODO: install symlinks for -32, -64 and -all as well
+installunixtools4way: installunixtools
+
+
 #
 # Like installunixtools, but only install links to the versioned binaries.
 #
@@ -77,18 +112,20 @@
 		$(INSTALL) -d -m $(DIRMODE) "$(DESTDIR)$(FRAMEWORKUNIXTOOLSPREFIX)/bin" ;\
 	fi
 	for fn in python$(VERSION) pythonw$(VERSION) idle$(VERSION) \
-		  pydoc$(VERSION) python-config$(VERSION) smtpd$(VERSION).py ;\
+		  pydoc$(VERSION) python$(VERSION)-config) smtpd$(VERSION).py ;\
 	do \
 		ln -fs "$(prefix)/bin/$${fn}" "$(DESTDIR)$(FRAMEWORKUNIXTOOLSPREFIX)/bin/$${fn}" ;\
 	done
 
+# TODO: -32, -64 and -all variants
+altinstallunixtools4way: altinstallunixtools
 
 # By default most tools are installed without a version in their basename, to
 # make it easier to install (and use) several python versions side-by-side move
 # the tools to a version-specific name and add the non-versioned name as an
 # alias.
 install_versionedtools:
-	for fn in idle pydoc python-config ;\
+	for fn in idle pydoc ;\
 	do \
 		if [ -h "$(DESTDIR)$(prefix)/bin/$${fn}" ]; then \
 			continue ;\
@@ -96,6 +133,10 @@
 		mv "$(DESTDIR)$(prefix)/bin/$${fn}" "$(DESTDIR)$(prefix)/bin/$${fn}$(VERSION)"  ;\
 		ln -sf "$${fn}$(VERSION)" "$(DESTDIR)$(prefix)/bin/$${fn}" ;\
 	done
+	if [ ! -h "$(DESTDIR)$(prefix)/bin/python-config" ]; then \
+		mv "$(DESTDIR)$(prefix)/bin/python-config" "$(DESTDIR)$(prefix)/bin/python$(VERSION)-config" ;\
+		ln -sf "python$(VERSION)-config" "$(DESTDIR)$(prefix)/bin/python-config" ; \
+	fi
 	if [ ! -h "$(DESTDIR)$(prefix)/bin/smtpd.py" ]; then \
 		mv "$(DESTDIR)$(prefix)/bin/smtpd.py" "$(DESTDIR)$(prefix)/bin/smtpd$(VERSION).py"  ;\
 		ln -sf "smtpd$(VERSION).py" "$(DESTDIR)$(prefix)/bin/smtpd.py" ;\
@@ -106,6 +147,13 @@
 	$(CC) $(LDFLAGS) -o $@ $(srcdir)/Tools/pythonw.c \
 		-DPYTHONWEXECUTABLE='"$(APPINSTALLDIR)/Contents/MacOS/$(PYTHONFRAMEWORK)"'
 
+pythonw-32: $(srcdir)/Tools/pythonw.c Makefile
+	$(CC) $(LDFLAGS) -o $@ -arch i386 -arch ppc $(srcdir)/Tools/pythonw.c \
+		-DPYTHONWEXECUTABLE='"$(APPINSTALLDIR)/Contents/MacOS/$(PYTHONFRAMEWORK)-32"'
+
+pythonw-64: $(srcdir)/Tools/pythonw.c Makefile
+	$(CC) $(LDFLAGS) -o $@ -arch x86_64 -arch ppc64 $(srcdir)/Tools/pythonw.c \
+		-DPYTHONWEXECUTABLE='"$(APPINSTALLDIR)/Contents/MacOS/$(PYTHONFRAMEWORK)-64"'
 
 install_PythonLauncher:
 	cd PythonLauncher && make install DESTDIR=$(DESTDIR)
@@ -158,6 +206,12 @@
 	done
 	$(INSTALL_PROGRAM) $(STRIPFLAG) $(BUILDPYTHON) "$(DESTDIR)$(APPINSTALLDIR)/Contents/MacOS/$(PYTHONFRAMEWORK)"
 
+install_Python4way: install_Python
+	lipo  -extract i386 -extract ppc7400 -output "$(DESTDIR)$(APPINSTALLDIR)/Contents/MacOS/$(PYTHONFRAMEWORK)-32" "$(DESTDIR)$(APPINSTALLDIR)/Contents/MacOS/$(PYTHONFRAMEWORK)"
+	lipo  -extract x86_64 -extract ppc64 -output "$(DESTDIR)$(APPINSTALLDIR)/Contents/MacOS/$(PYTHONFRAMEWORK)-64" "$(DESTDIR)$(APPINSTALLDIR)/Contents/MacOS/$(PYTHONFRAMEWORK)"
+
+
+
 install_IDLE:
 	test -d "$(DESTDIR)$(PYTHONAPPSDIR)" || mkdir -p "$(DESTDIR)$(PYTHONAPPSDIR)"
 	-test -d "$(DESTDIR)$(PYTHONAPPSDIR)/IDLE.app" && rm -r "$(DESTDIR)$(PYTHONAPPSDIR)/IDLE.app"
diff --git a/Makefile.pre.in b/Makefile.pre.in
index a6a4950..8d88744 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -428,7 +428,7 @@
 		$(RESSRCDIR)/Info.plist
 	$(INSTALL) -d -m $(DIRMODE) $(PYTHONFRAMEWORKDIR)/Versions/$(VERSION)
 	if test "${UNIVERSALSDK}"; then \
-		$(CC) -o $(LDLIBRARY) -arch i386 -arch ppc -dynamiclib \
+		$(CC) -o $(LDLIBRARY) @UNIVERSAL_ARCH_FLAGS@ -dynamiclib \
 			-isysroot "${UNIVERSALSDK}" \
 			-all_load $(LIBRARY) -Wl,-single_module \
 			-install_name $(DESTDIR)$(PYTHONFRAMEWORKINSTALLDIR)/Versions/$(VERSION)/$(PYTHONFRAMEWORK) \
@@ -1031,13 +1031,22 @@
 frameworkinstallapps:
 	cd Mac && $(MAKE) installapps DESTDIR="$(DESTDIR)"
 
+frameworkinstallapps4way:
+	cd Mac && $(MAKE) installapps4way DESTDIR="$(DESTDIR)"
+
 # This install the unix python and pythonw tools in /usr/local/bin
 frameworkinstallunixtools:
 	cd Mac && $(MAKE) installunixtools DESTDIR="$(DESTDIR)"
 
+frameworkinstallunixtools4way:
+	cd Mac && $(MAKE) installunixtools4way DESTDIR="$(DESTDIR)"
+
 frameworkaltinstallunixtools:
 	cd Mac && $(MAKE) altinstallunixtools DESTDIR="$(DESTDIR)"
 
+frameworkaltinstallunixtools4way:
+	cd Mac && $(MAKE) altinstallunixtools4way DESTDIR="$(DESTDIR)"
+
 # This installs the Demos and Tools into the applications directory.
 # It is not part of a normal frameworkinstall
 frameworkinstallextras:
@@ -1182,7 +1191,7 @@
 
 # Perform some verification checks on any modified files.
 check:
-	./$(BUILDPYTHON) $(srcdir)/Tools/scripts/patchcheck.py
+	$(RUNSHARED) ./$(BUILDPYTHON) $(srcdir)/Tools/scripts/patchcheck.py
 
 # Dependencies
 
diff --git a/Modules/_ctypes/cfield.c b/Modules/_ctypes/cfield.c
index 6cf56a8..beca018 100644
--- a/Modules/_ctypes/cfield.c
+++ b/Modules/_ctypes/cfield.c
@@ -1778,6 +1778,7 @@
 #ifdef ffi_type_longdouble
 #undef ffi_type_longdouble
 #endif
+  /* This is already defined on OSX */
 ffi_type ffi_type_longdouble = { sizeof(long double), LONGDOUBLE_ALIGN,
 				 FFI_TYPE_LONGDOUBLE };
 
diff --git a/Modules/_ctypes/libffi_osx/x86/x86-darwin.S b/Modules/_ctypes/libffi_osx/x86/x86-darwin.S
index d91bdc0..040cec6 100644
--- a/Modules/_ctypes/libffi_osx/x86/x86-darwin.S
+++ b/Modules/_ctypes/libffi_osx/x86/x86-darwin.S
@@ -179,7 +179,6 @@
         movl %ebp,%esp
         popl %ebp
         ret
-.LFE1:
 .ffi_call_SYSV_end:
 #if 0
         .size    ffi_call_SYSV,.ffi_call_SYSV_end-ffi_call_SYSV
@@ -220,7 +219,7 @@
 #else
 	.long	.LFB1	/* FDE initial location */
 #endif
-	.long	.LFE1-.LFB1	/* FDE address range */
+	.long	.ffi_call_SYSV_end-.LFB1	/* FDE address range */
 #ifdef __PIC__
 	.byte	0x0	/* .uleb128 0x0; Augmentation size */
 #endif
diff --git a/configure.in b/configure.in
index 1674c40..871592a 100644
--- a/configure.in
+++ b/configure.in
@@ -57,6 +57,12 @@
 # u_int on Irix 5.3. Defining _BSD_TYPES brings it back.
 AC_DEFINE(_BSD_TYPES, 1, [Define on Irix to enable u_int])
 
+# The later defininition of _XOPEN_SOURCE and _POSIX_C_SOURCE disables
+# certain features on Mac OS X, so we need _DARWIN_C_SOURCE to re-enable
+# them.
+AC_DEFINE(_DARWIN_C_SOURCE, 1, [Define on Darwin to activate all library features])
+
+
 define_xopen_source=yes
 
 # Arguments passed to configure.
@@ -86,6 +92,20 @@
 ])
 AC_SUBST(UNIVERSALSDK)
 
+UNIVERSAL_ARCHS="32-bit"
+AC_MSG_CHECKING(for --with-universal-archs)
+AC_ARG_WITH(universal-archs,
+    AC_HELP_STRING(--with-universal-archs=ARCH, select architectures for universal build ("32-bit", "64-bit" or "all")),
+[
+	AC_MSG_RESULT($withval)
+	UNIVERSAL_ARCHS="$withval"
+],
+[
+ 	AC_MSG_RESULT(32-bit)
+])
+
+
+
 AC_ARG_WITH(framework-name,
               AC_HELP_STRING(--with-framework-name=FRAMEWORK, 
                              specify an alternate name of the framework built with --enable-framework),
@@ -127,9 +147,14 @@
 		PYTHONFRAMEWORKPREFIX=$enableval
 		PYTHONFRAMEWORKINSTALLDIR=$PYTHONFRAMEWORKPREFIX/$PYTHONFRAMEWORKDIR
 		FRAMEWORKINSTALLFIRST="frameworkinstallstructure"
-		FRAMEWORKINSTALLLAST="frameworkinstallmaclib frameworkinstallapps frameworkinstallunixtools"
-		FRAMEWORKALTINSTALLFIRST="${FRAMEWORKINSTALLFIRST} bininstall maninstall"
-		FRAMEWORKALTINSTALLLAST="frameworkinstallmaclib frameworkinstallapps frameworkaltinstallunixtools"
+		FRAMEWORKALTINSTALLFIRST="frameworkinstallstructure bininstall maninstall"
+		if test "$UNIVERSAL_ARCHS" = "all"
+		then
+			FRAMEWORKINSTALLLAST="frameworkinstallmaclib frameworkinstallapps4way frameworkinstallunixtools4way"
+		else
+			FRAMEWORKALTINSTALLLAST="frameworkinstallmaclib frameworkinstallapps frameworkaltinstallunixtools"
+		fi
+
 		if test "x${prefix}" = "xNONE" ; then
 			FRAMEWORKUNIXTOOLSPREFIX="${ac_default_prefix}"
 		else
@@ -159,6 +184,12 @@
 		FRAMEWORKUNIXTOOLSPREFIX="${prefix}"
 	fi
 	enable_framework=
+
+	if test "$UNIVERSAL_ARCHS" = "all" 
+	then
+		FRAMEWORKINSTALLLAST=update4wayuniversal
+		FRAMEWORKALTINSTALLLAST=update4wayuniversal
+	fi
 ])
 AC_SUBST(PYTHONFRAMEWORK)
 AC_SUBST(PYTHONFRAMEWORKIDENTIFIER)
@@ -782,6 +813,11 @@
 fi
 
 AC_SUBST(BASECFLAGS)
+
+# The -arch flags for universal builds on OSX
+UNIVERSAL_ARCH_FLAGS=
+AC_SUBST(UNIVERSAL_ARCH_FLAGS)
+
 # tweak BASECFLAGS based on compiler and platform
 case $GCC in
 yes)
@@ -820,7 +856,23 @@
 	    # -Wno-long-double, -no-cpp-precomp, and -mno-fused-madd
 	    # used to be here, but non-Apple gcc doesn't accept them.
 	    if test "${enable_universalsdk}"; then
-		BASECFLAGS="-arch ppc -arch i386 -isysroot ${UNIVERSALSDK} ${BASECFLAGS}"
+		UNIVERSAL_ARCH_FLAGS=""
+	        if test "$UNIVERSAL_ARCHS" = "32-bit" ; then
+		   UNIVERSAL_ARCH_FLAGS="-arch ppc -arch i386"
+
+	         elif test "$UNIVERSAL_ARCHS" = "64-bit" ; then
+		   UNIVERSAL_ARCH_FLAGS="-arch ppc64 -arch x86_64"
+
+	         elif test "$UNIVERSAL_ARCHS" = "all" ; then
+		   UNIVERSAL_ARCH_FLAGS="-arch i386 -arch ppc -arch ppc64 -arch x86_64"
+
+		 else
+	           AC_MSG_ERROR([proper usage is --with-universalarch=32-bit|64-bit|all])
+
+		 fi
+
+
+		BASECFLAGS="${UNIVERSAL_ARCH_FLAGS} -isysroot ${UNIVERSALSDK} ${BASECFLAGS}"
 	    fi
 
 	    ;;
@@ -1495,6 +1547,12 @@
 		if test ${cur_target} '>' 10.2; then
 			cur_target=10.3
 		fi
+		if test "${UNIVERSAL_ARCHS}" = "all"; then
+			# Ensure that the default platform for a 4-way
+			# universal build is OSX 10.5, that's the first
+			# OS release where 4-way builds make sense.
+			cur_target='10.5'
+		fi
 		CONFIGURE_MACOSX_DEPLOYMENT_TARGET=${MACOSX_DEPLOYMENT_TARGET-${cur_target}}
 
 		# Make sure that MACOSX_DEPLOYMENT_TARGET is set in the 
@@ -1505,10 +1563,10 @@
 		export MACOSX_DEPLOYMENT_TARGET
 
 		EXPORT_MACOSX_DEPLOYMENT_TARGET=''
-		if test ${MACOSX_DEPLOYMENT_TARGET-${cur_target}} '>' 10.2
+		if test ${MACOSX_DEPLOYMENT_TARGET} '>' 10.2
 		then
 			if test "${enable_universalsdk}"; then
-				LDFLAGS="-arch i386 -arch ppc -isysroot ${UNIVERSALSDK} ${LDFLAGS}"
+				LDFLAGS="${UNIVERSAL_ARCH_FLAGS} -isysroot ${UNIVERSALSDK} ${LDFLAGS}"
 			fi
 			LDSHARED='$(CC) $(LDFLAGS) -bundle -undefined dynamic_lookup'
 			BLDSHARED="$LDSHARED"
@@ -3098,23 +3156,6 @@
 
 # check for endianness
 AC_C_BIGENDIAN
-AH_VERBATIM([WORDS_BIGENDIAN],
-[
- /* Define to 1 if your processor stores words with the most significant byte
-    first (like Motorola and SPARC, unlike Intel and VAX). 
-
-    The block below does compile-time checking for endianness on platforms
-    that use GCC and therefore allows compiling fat binaries on OSX by using 
-    '-arch ppc -arch i386' as the compile flags. The phrasing was choosen
-    such that the configure-result is used on systems that don't use GCC.
-  */
-#ifdef __BIG_ENDIAN__
-#define WORDS_BIGENDIAN 1
-#else
-#ifndef __LITTLE_ENDIAN__
-#undef WORDS_BIGENDIAN
-#endif
-#endif])
 
 # Check whether right shifting a negative integer extends the sign bit
 # or fills with zeros (like the Cray J90, according to Tim Peters).
diff --git a/pyconfig.h.in b/pyconfig.h.in
index d5ec2b0..ee38b4b 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -489,6 +489,9 @@
 /* Define if you have readline 4.2 */
 #undef HAVE_RL_COMPLETION_MATCHES
 
+/* Define when using libedit's readline emulation */
+#undef HAVE_RL_DISPM_VFUNC
+
 /* Define if you have readline 4.0 */
 #undef HAVE_RL_PRE_INPUT_HOOK
 
@@ -976,22 +979,9 @@
 /* Define to profile with the Pentium timestamp counter */
 #undef WITH_TSC
 
-
- /* Define to 1 if your processor stores words with the most significant byte
-    first (like Motorola and SPARC, unlike Intel and VAX). 
-
-    The block below does compile-time checking for endianness on platforms
-    that use GCC and therefore allows compiling fat binaries on OSX by using 
-    '-arch ppc -arch i386' as the compile flags. The phrasing was choosen
-    such that the configure-result is used on systems that don't use GCC.
-  */
-#ifdef __BIG_ENDIAN__
-#define WORDS_BIGENDIAN 1
-#else
-#ifndef __LITTLE_ENDIAN__
+/* Define to 1 if your processor stores words with the most significant byte
+   first (like Motorola and SPARC, unlike Intel and VAX). */
 #undef WORDS_BIGENDIAN
-#endif
-#endif
 
 /* Define to 1 if on AIX 3.
    System headers sometimes define this.
@@ -1006,6 +996,9 @@
 /* Define on Irix to enable u_int */
 #undef _BSD_TYPES
 
+/* Define on Darwin to activate all library features */
+#undef _DARWIN_C_SOURCE
+
 /* This must be set to 64 on some systems to enable large file support. */
 #undef _FILE_OFFSET_BITS
 
diff --git a/setup.py b/setup.py
index d73e765..0519bf7 100644
--- a/setup.py
+++ b/setup.py
@@ -241,6 +241,19 @@
                 'WARNING: skipping import check for Carbon-based "%s"' %
                 ext.name)
             return
+
+        if self.get_platform() == 'darwin' and (
+                sys.maxint > 2**32 and '-arch' in ext.extra_link_args):
+            # Don't bother doing an import check when an extension was
+            # build with an explicit '-arch' flag on OSX. That's currently
+            # only used to build 32-bit only extensions in a 4-way
+            # universal build and loading 32-bit code into a 64-bit
+            # process will fail.
+            self.announce(
+                'WARNING: skipping import check for "%s"' %
+                ext.name)
+            return
+
         # Workaround for Cygwin: Cygwin currently has fork issues when many
         # modules have been imported
         if self.get_platform() == 'cygwin':
@@ -507,10 +520,12 @@
 
         # readline
         do_readline = self.compiler.find_library_file(lib_dirs, 'readline')
-        if platform == 'darwin':
+        if platform == 'darwin': # and os.uname()[2] < '9.':
             # MacOSX 10.4 has a broken readline. Don't try to build
             # the readline module unless the user has installed a fixed
             # readline package
+            # FIXME: The readline emulation on 10.5 is better, but the
+            # readline module doesn't compile out of the box.
             if find_file('readline/rlconf.h', inc_dirs, []) is None:
                 do_readline = False
         if do_readline:
@@ -1242,11 +1257,29 @@
         include_dirs.append('/usr/X11R6/include')
         frameworks = ['-framework', 'Tcl', '-framework', 'Tk']
 
+        # All existing framework builds of Tcl/Tk don't support 64-bit
+        # architectures.
+        cflags = sysconfig.get_config_vars('CFLAGS')[0]
+        archs = re.findall('-arch\s+(\w+)', cflags)
+        if 'x86_64' in archs or 'ppc64' in archs:
+            try:
+                archs.remove('x86_64')
+            except ValueError:
+                pass
+            try:
+                archs.remove('ppc64')
+            except ValueError:
+                pass
+
+            for a in archs:
+                frameworks.append('-arch')
+                frameworks.append(a)
+
         ext = Extension('_tkinter', ['_tkinter.c', 'tkappinit.c'],
                         define_macros=[('WITH_APPINIT', 1)],
                         include_dirs = include_dirs,
                         libraries = [],
-                        extra_compile_args = frameworks,
+                        extra_compile_args = frameworks[2:],
                         extra_link_args = frameworks,
                         )
         self.extensions.append(ext)
@@ -1377,6 +1410,7 @@
                                                   '_ctypes', 'libffi_osx'))
         sources = [os.path.join(ffi_srcdir, p)
                    for p in ['ffi.c',
+                             'x86/darwin64.S',
                              'x86/x86-darwin.S',
                              'x86/x86-ffi_darwin.c',
                              'x86/x86-ffi64.c',