diff --git a/Lib/idlelib/INSTALL.txt b/Lib/idlelib/INSTALL.txt
index ed7ac69..2488d28 100644
--- a/Lib/idlelib/INSTALL.txt
+++ b/Lib/idlelib/INSTALL.txt
@@ -41,6 +41,17 @@
 	at python1.5.  If so, change the first line in the /usr/bin/idle 
 	script to read:
 	       !# /usr/bin/python2.2
+
+	On Mac OS X, /usr/bin/python may be pointing at the OS-installed
+	python, which does not have GUI support. Change the first line of
+	/usr/bin/idle to read:
+		#! /usr/bin/env pythonw
+
+	Also, to build an IDLE application that can be used from the Finder
+	on Mac OS X, run:
+		pythonw buildapp.py build
+		open build
+	You will see an IDLE application.
 	       
 See README.txt for more details on this version of IDLEfork. 
 
diff --git a/Lib/idlelib/PyShell.py b/Lib/idlelib/PyShell.py
index af3267a..6e3a43a 100644
--- a/Lib/idlelib/PyShell.py
+++ b/Lib/idlelib/PyShell.py
@@ -311,29 +311,15 @@
         self.rpcpid = os.spawnv(os.P_NOWAIT, args[0], args)
 
     def build_subprocess_arglist(self):
-        if sys.platform == 'darwin' and sys.argv[0].count('.app'):
-            # We need to avoid using sys.executable because it fails on some
-            # of the applet architectures On Mac OS X.
-            #
-            # here are the applet architectures tried:
-            #
-            # framework applet: sys.executable + -p is correct
-            # python 2.2 + pure python main applet:
-            #                   sys.executable + -p is correct
-            # pythonw idle.py:  sys.executable + -c is correct
-            #
-            # XXX what about warnoptions?
-            return [sys.executable, '-p', str(self.port)]
+        w = ['-W' + s for s in sys.warnoptions]
+        # Maybe IDLE is installed and is being accessed via sys.path,
+        # or maybe it's not installed and the idle.py script is being
+        # run from the IDLE source directory.
+        if __name__ == 'idlelib.PyShell':
+            command = "__import__('idlelib.run').run.main()"
         else:
-            w = ['-W' + s for s in sys.warnoptions]
-            # Maybe IDLE is installed and is being accessed via sys.path,
-            # or maybe it's not installed and the idle.py script is being
-            # run from the IDLE source directory.
-            if __name__ == 'idlelib.PyShell':
-                command = "__import__('idlelib.run').run.main()"
-            else:
-                command = "__import__('run').main()"
-            return [sys.executable] + w + ["-c", command, str(self.port)]
+            command = "__import__('run').main()"
+        return [sys.executable] + w + ["-c", command, str(self.port)]
 
     def start_subprocess(self):
         addr = ("localhost", self.port)
diff --git a/Lib/idlelib/buildapp.py b/Lib/idlelib/buildapp.py
new file mode 100644
index 0000000..42aeeb7
--- /dev/null
+++ b/Lib/idlelib/buildapp.py
@@ -0,0 +1,16 @@
+#
+# After running python setup.py install, run this program from the command 
+# line like so:
+#
+# % python2.3 buildapp.py build
+#
+# A double-clickable IDLE application will be created in the build/ directory.
+#
+
+from bundlebuilder import buildapp
+
+buildapp(
+	name="IDLE",
+	mainprogram="idle.py",
+	argv_emulation=1,
+)
diff --git a/Lib/idlelib/macosx_main.py b/Lib/idlelib/macosx_main.py
deleted file mode 100644
index bc91a0b..0000000
--- a/Lib/idlelib/macosx_main.py
+++ /dev/null
@@ -1,42 +0,0 @@
-#!/usr/bin/env pythonw
-# IDLE.app
-#
-# Installation:
-#   see the install_IDLE target in python/dist/src/Mac/OSX/Makefile
-#
-# Usage:
-#
-# 1. Double clicking IDLE icon will open IDLE.
-# 2. Dropping file on IDLE icon will open that file in IDLE.
-# 3. Launch from command line with files with this command-line:
-#
-#     /Applications/Python/IDLE.app/Contents/MacOS/python file1 file2 file3
-#
-#
-
-# Add IDLE.app/Contents/Resources/idlelib to path.
-# __file__ refers to this file when it is used as a module, sys.argv[0]
-# refers to this file when it is used as a script (pythonw macosx_main.py)
-import sys
-
-from os.path import split, join, isdir
-try:
-    __file__
-except NameError:
-    __file__ = sys.argv[0]
-idlelib = join(split(__file__)[0], 'idlelib')
-if isdir(idlelib):
-    sys.path.append(idlelib)
-
-# see if we are being asked to execute the subprocess code
-if '-p' in sys.argv:
-    # run expects only the port number in sys.argv
-    sys.argv.remove('-p')
-
-    # this module will become the namespace used by the interactive
-    # interpreter; remove all variables we have defined.
-    del sys, __file__, split, join, isdir, idlelib
-    __import__('run').main()
-else:
-    # Load idlelib/idle.py which starts the application.
-    import idle