diff --git a/Tools/scripts/byteyears.py b/Tools/scripts/byteyears.py
index b2a114f..ba38caf 100755
--- a/Tools/scripts/byteyears.py
+++ b/Tools/scripts/byteyears.py
@@ -9,48 +9,53 @@
 import sys, os, time
 from stat import *
 
-# Use lstat() to stat files if it exists, else stat()
-try:
-    statfunc = os.lstat
-except AttributeError:
-    statfunc = os.stat
+def main():
 
-# Parse options
-if sys.argv[1] == '-m':
-    itime = ST_MTIME
-    del sys.argv[1]
-elif sys.argv[1] == '-c':
-    itime = ST_CTIME
-    del sys.argv[1]
-elif sys.argv[1] == '-a':
-    itime = ST_CTIME
-    del sys.argv[1]
-else:
-    itime = ST_MTIME
-
-secs_per_year = 365.0 * 24.0 * 3600.0   # Scale factor
-now = time.time()                       # Current time, for age computations
-status = 0                              # Exit status, set to 1 on errors
-
-# Compute max file name length
-maxlen = 1
-for filename in sys.argv[1:]:
-    maxlen = max(maxlen, len(filename))
-
-# Process each argument in turn
-for filename in sys.argv[1:]:
+    # Use lstat() to stat files if it exists, else stat()
     try:
-        st = statfunc(filename)
-    except os.error, msg:
-        sys.stderr.write("can't stat %r: %r\n" % (filename, msg))
-        status = 1
-        st = ()
-    if st:
-        anytime = st[itime]
-        size = st[ST_SIZE]
-        age = now - anytime
-        byteyears = float(size) * float(age) / secs_per_year
-        print filename.ljust(maxlen),
-        print repr(int(byteyears)).rjust(8)
+        statfunc = os.lstat
+    except AttributeError:
+        statfunc = os.stat
 
-sys.exit(status)
+    # Parse options
+    if sys.argv[1] == '-m':
+        itime = ST_MTIME
+        del sys.argv[1]
+    elif sys.argv[1] == '-c':
+        itime = ST_CTIME
+        del sys.argv[1]
+    elif sys.argv[1] == '-a':
+        itime = ST_CTIME
+        del sys.argv[1]
+    else:
+        itime = ST_MTIME
+
+    secs_per_year = 365.0 * 24.0 * 3600.0   # Scale factor
+    now = time.time()                       # Current time, for age computations
+    status = 0                              # Exit status, set to 1 on errors
+
+    # Compute max file name length
+    maxlen = 1
+    for filename in sys.argv[1:]:
+        maxlen = max(maxlen, len(filename))
+
+    # Process each argument in turn
+    for filename in sys.argv[1:]:
+        try:
+            st = statfunc(filename)
+        except os.error, msg:
+            sys.stderr.write("can't stat %r: %r\n" % (filename, msg))
+            status = 1
+            st = ()
+        if st:
+            anytime = st[itime]
+            size = st[ST_SIZE]
+            age = now - anytime
+            byteyears = float(size) * float(age) / secs_per_year
+            print filename.ljust(maxlen),
+            print repr(int(byteyears)).rjust(8)
+
+    sys.exit(status)
+
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/checkpyc.py b/Tools/scripts/checkpyc.py
index d5f3c7a..8af7672 100755
--- a/Tools/scripts/checkpyc.py
+++ b/Tools/scripts/checkpyc.py
@@ -62,4 +62,5 @@
         return -1
     return ord(s[0]) + (ord(s[1])<<8) + (ord(s[2])<<16) + (ord(s[3])<<24)
 
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/classfix.py b/Tools/scripts/classfix.py
index 520b352..cdf006a 100755
--- a/Tools/scripts/classfix.py
+++ b/Tools/scripts/classfix.py
@@ -186,4 +186,5 @@
 
     return head + '(' + basepart + '):' + tail
 
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/copytime.py b/Tools/scripts/copytime.py
index 74c29c9..209c492 100755
--- a/Tools/scripts/copytime.py
+++ b/Tools/scripts/copytime.py
@@ -22,4 +22,5 @@
         sys.stderr.write(file2 + ': cannot change time\n')
         sys.exit(2)
 
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/crlf.py b/Tools/scripts/crlf.py
index 4fb8be3..03908b1 100755
--- a/Tools/scripts/crlf.py
+++ b/Tools/scripts/crlf.py
@@ -1,19 +1,24 @@
 #! /usr/bin/env python
-
 "Replace CRLF with LF in argument files.  Print names of changed files."
 
 import sys, os
-for filename in sys.argv[1:]:
-    if os.path.isdir(filename):
-        print filename, "Directory!"
-        continue
-    data = open(filename, "rb").read()
-    if '\0' in data:
-        print filename, "Binary!"
-        continue
-    newdata = data.replace("\r\n", "\n")
-    if newdata != data:
-        print filename
-        f = open(filename, "wb")
-        f.write(newdata)
-        f.close()
+
+def main():
+    for filename in sys.argv[1:]:
+        if os.path.isdir(filename):
+            print filename, "Directory!"
+            continue
+        data = open(filename, "rb").read()
+        if '\0' in data:
+            print filename, "Binary!"
+            continue
+        newdata = data.replace("\r\n", "\n")
+        if newdata != data:
+            print filename
+            f = open(filename, "wb")
+            f.write(newdata)
+            f.close()
+
+if __name__ == '__main__':
+    main()
+
diff --git a/Tools/scripts/cvsfiles.py b/Tools/scripts/cvsfiles.py
index 2168556..53b4294 100755
--- a/Tools/scripts/cvsfiles.py
+++ b/Tools/scripts/cvsfiles.py
@@ -68,4 +68,5 @@
         return 0
     return st[stat.ST_MTIME]
 
-sys.exit(main())
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/diff.py b/Tools/scripts/diff.py
index d452668..ecbff61 100644
--- a/Tools/scripts/diff.py
+++ b/Tools/scripts/diff.py
@@ -8,33 +8,38 @@
 
 import sys, os, time, difflib, optparse
 
-usage = "usage: %prog [options] fromfile tofile"
-parser = optparse.OptionParser(usage)
-parser.add_option("-c", action="store_true", default=False, help='Produce a context format diff (default)')
-parser.add_option("-u", action="store_true", default=False, help='Produce a unified format diff')
-parser.add_option("-n", action="store_true", default=False, help='Produce a ndiff format diff')
-parser.add_option("-l", "--lines", type="int", default=3, help='Set number of context lines (default 3)')
-(options, args) = parser.parse_args()
+def main():
 
-if len(args) == 0:
-    parser.print_help()
-    sys.exit(1)
-if len(args) != 2:
-    parser.error("need to specify both a fromfile and tofile")
+    usage = "usage: %prog [options] fromfile tofile"
+    parser = optparse.OptionParser(usage)
+    parser.add_option("-c", action="store_true", default=False, help='Produce a context format diff (default)')
+    parser.add_option("-u", action="store_true", default=False, help='Produce a unified format diff')
+    parser.add_option("-n", action="store_true", default=False, help='Produce a ndiff format diff')
+    parser.add_option("-l", "--lines", type="int", default=3, help='Set number of context lines (default 3)')
+    (options, args) = parser.parse_args()
 
-n = options.lines
-fromfile, tofile = args
+    if len(args) == 0:
+        parser.print_help()
+        sys.exit(1)
+    if len(args) != 2:
+        parser.error("need to specify both a fromfile and tofile")
 
-fromdate = time.ctime(os.stat(fromfile).st_mtime)
-todate = time.ctime(os.stat(tofile).st_mtime)
-fromlines = open(fromfile).readlines()
-tolines = open(tofile).readlines()
+    n = options.lines
+    fromfile, tofile = args
 
-if options.u:
-    diff = difflib.unified_diff(fromlines, tolines, fromfile, tofile, fromdate, todate, n=n)
-elif options.n:
-    diff = difflib.ndiff(fromlines, tolines)
-else:
-    diff = difflib.context_diff(fromlines, tolines, fromfile, tofile, fromdate, todate, n=n)
+    fromdate = time.ctime(os.stat(fromfile).st_mtime)
+    todate = time.ctime(os.stat(tofile).st_mtime)
+    fromlines = open(fromfile).readlines()
+    tolines = open(tofile).readlines()
 
-sys.stdout.writelines(diff)
+    if options.u:
+        diff = difflib.unified_diff(fromlines, tolines, fromfile, tofile, fromdate, todate, n=n)
+    elif options.n:
+        diff = difflib.ndiff(fromlines, tolines)
+    else:
+        diff = difflib.context_diff(fromlines, tolines, fromfile, tofile, fromdate, todate, n=n)
+
+    sys.stdout.writelines(diff)
+
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/dutree.py b/Tools/scripts/dutree.py
index a49d80a..d938ae1 100755
--- a/Tools/scripts/dutree.py
+++ b/Tools/scripts/dutree.py
@@ -56,4 +56,5 @@
         if d.has_key(key):
             show(tsub, d[key][1], psub)
 
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/findlinksto.py b/Tools/scripts/findlinksto.py
index 00d4a18..8dd4bfb 100755
--- a/Tools/scripts/findlinksto.py
+++ b/Tools/scripts/findlinksto.py
@@ -39,4 +39,5 @@
         except os.error:
             pass
 
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/fixcid.py b/Tools/scripts/fixcid.py
index 76841fe..42aa835 100755
--- a/Tools/scripts/fixcid.py
+++ b/Tools/scripts/fixcid.py
@@ -310,4 +310,5 @@
         Dict[key] = value
     fp.close()
 
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/fixheader.py b/Tools/scripts/fixheader.py
index 02b4f3b..1bf5c52 100755
--- a/Tools/scripts/fixheader.py
+++ b/Tools/scripts/fixheader.py
@@ -45,4 +45,5 @@
     print '#endif'
     print '#endif /*', '!'+magic, '*/'
 
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/fixps.py b/Tools/scripts/fixps.py
index 12e9f43..2ff15f4 100755
--- a/Tools/scripts/fixps.py
+++ b/Tools/scripts/fixps.py
@@ -29,5 +29,5 @@
         f.write(rest)
         f.close()
 
-
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/google.py b/Tools/scripts/google.py
index d9fe0ac..b2ab1a4 100755
--- a/Tools/scripts/google.py
+++ b/Tools/scripts/google.py
@@ -19,4 +19,5 @@
     url = "http://www.google.com/search?q=%s" % s
     webbrowser.open(url)
 
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/gprof2html.py b/Tools/scripts/gprof2html.py
index aa13d52..cb01c2c 100755
--- a/Tools/scripts/gprof2html.py
+++ b/Tools/scripts/gprof2html.py
@@ -75,4 +75,5 @@
     output.close()
     webbrowser.open("file:" + os.path.abspath(outputfilename))
 
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/h2py.py b/Tools/scripts/h2py.py
index e2f6054..63e7336 100755
--- a/Tools/scripts/h2py.py
+++ b/Tools/scripts/h2py.py
@@ -171,4 +171,5 @@
                     sys.stderr.write('Warning - could not find file %s\n' %
                                      filename)
 
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/idle b/Tools/scripts/idle
index a209d56..1ba2a2c 100644
--- a/Tools/scripts/idle
+++ b/Tools/scripts/idle
@@ -1,4 +1,5 @@
 #! /usr/bin/env python
 
 from idlelib.PyShell import main
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/ifdef.py b/Tools/scripts/ifdef.py
index 15777f4..7e7b5cc 100755
--- a/Tools/scripts/ifdef.py
+++ b/Tools/scripts/ifdef.py
@@ -109,4 +109,5 @@
     if stack:
         sys.stderr.write('stack: %s\n' % stack)
 
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/lfcr.py b/Tools/scripts/lfcr.py
index 3baac97..babafae 100755
--- a/Tools/scripts/lfcr.py
+++ b/Tools/scripts/lfcr.py
@@ -3,17 +3,22 @@
 "Replace LF with CRLF in argument files.  Print names of changed files."
 
 import sys, re, os
-for filename in sys.argv[1:]:
-    if os.path.isdir(filename):
-        print filename, "Directory!"
-        continue
-    data = open(filename, "rb").read()
-    if '\0' in data:
-        print filename, "Binary!"
-        continue
-    newdata = re.sub("\r?\n", "\r\n", data)
-    if newdata != data:
-        print filename
-        f = open(filename, "wb")
-        f.write(newdata)
-        f.close()
+
+def main():
+    for filename in sys.argv[1:]:
+        if os.path.isdir(filename):
+            print filename, "Directory!"
+            continue
+        data = open(filename, "rb").read()
+        if '\0' in data:
+            print filename, "Binary!"
+            continue
+        newdata = re.sub("\r?\n", "\r\n", data)
+        if newdata != data:
+            print filename
+            f = open(filename, "wb")
+            f.write(newdata)
+            f.close()
+
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/linktree.py b/Tools/scripts/linktree.py
index 502873e..995f2ef 100755
--- a/Tools/scripts/linktree.py
+++ b/Tools/scripts/linktree.py
@@ -76,4 +76,5 @@
             else:
                 os.symlink(linkname, newname)
 
-sys.exit(main())
+if __name__ == '__main__':
+    sys.exit(main())
diff --git a/Tools/scripts/lll.py b/Tools/scripts/lll.py
index cbcd80a..dc21cf7 100755
--- a/Tools/scripts/lll.py
+++ b/Tools/scripts/lll.py
@@ -13,13 +13,17 @@
             full = os.path.join(dirname, name)
             if os.path.islink(full):
                 print name, '->', os.readlink(full)
-
-args = sys.argv[1:]
-if not args: args = [os.curdir]
-first = 1
-for arg in args:
-    if len(args) > 1:
-        if not first: print
-        first = 0
-        print arg + ':'
+def main():
+    args = sys.argv[1:]
+    if not args: args = [os.curdir]
+    first = 1
+    for arg in args:
+        if len(args) > 1:
+            if not first: print
+            first = 0
+            print arg + ':'
     lll(arg)
+
+if __name__ == '__main__':
+    main()
+
diff --git a/Tools/scripts/logmerge.py b/Tools/scripts/logmerge.py
index 54d1676..edfec2c 100755
--- a/Tools/scripts/logmerge.py
+++ b/Tools/scripts/logmerge.py
@@ -177,8 +177,9 @@
         prev.append((date, working_file, rev, author))
         prevtext = text
 
-try:
-    main()
-except IOError, e:
-    if e.errno != errno.EPIPE:
-        raise
+if __name__ == '__main__':
+    try:
+        main()
+    except IOError, e:
+        if e.errno != errno.EPIPE:
+            raise
diff --git a/Tools/scripts/methfix.py b/Tools/scripts/methfix.py
index 9200d265..a872ab7 100755
--- a/Tools/scripts/methfix.py
+++ b/Tools/scripts/methfix.py
@@ -167,5 +167,5 @@
         line = line[:a] + line[c:d] + line[b:]
     return line
 
-
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/mkreal.py b/Tools/scripts/mkreal.py
index a890ac7..fb9e9a5 100755
--- a/Tools/scripts/mkreal.py
+++ b/Tools/scripts/mkreal.py
@@ -62,4 +62,5 @@
                 mkrealfile(name)
     sys.exit(status)
 
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/objgraph.py b/Tools/scripts/objgraph.py
index c48a425..01060f9 100755
--- a/Tools/scripts/objgraph.py
+++ b/Tools/scripts/objgraph.py
@@ -208,7 +208,8 @@
 # Use its return value as exit status.
 # Catch interrupts to avoid stack trace.
 #
-try:
-    sys.exit(main())
-except KeyboardInterrupt:
-    sys.exit(1)
+if __name__ == '__main__':
+    try:
+        sys.exit(main())
+    except KeyboardInterrupt:
+        sys.exit(1)
diff --git a/Tools/scripts/pathfix.py b/Tools/scripts/pathfix.py
index 47ae464..5798d9b 100755
--- a/Tools/scripts/pathfix.py
+++ b/Tools/scripts/pathfix.py
@@ -145,4 +145,6 @@
         return line
     return '#! %s\n' % new_interpreter
 
-main()
+if __name__ == '__main__':
+    main()
+
diff --git a/Tools/scripts/pdeps.py b/Tools/scripts/pdeps.py
index 1589709..e835f84 100755
--- a/Tools/scripts/pdeps.py
+++ b/Tools/scripts/pdeps.py
@@ -160,7 +160,8 @@
 
 
 # Call main and honor exit status
-try:
-    sys.exit(main())
-except KeyboardInterrupt:
-    sys.exit(1)
+if __name__ == '__main__':
+    try:
+        sys.exit(main())
+    except KeyboardInterrupt:
+        sys.exit(1)
diff --git a/Tools/scripts/ptags.py b/Tools/scripts/ptags.py
index de6e901..ac01356 100755
--- a/Tools/scripts/ptags.py
+++ b/Tools/scripts/ptags.py
@@ -49,4 +49,5 @@
             s = name + '\t' + filename + '\t/^' + content + '/\n'
             tags.append(s)
 
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/pydoc b/Tools/scripts/pydoc
index 0964929..0879a42 100755
--- a/Tools/scripts/pydoc
+++ b/Tools/scripts/pydoc
@@ -1,4 +1,5 @@
 #!/usr/bin/env python
 
 import pydoc
-pydoc.cli()
+if __name__ == '__main__':
+    pydoc.cli()
diff --git a/Tools/scripts/pydocgui.pyw b/Tools/scripts/pydocgui.pyw
index 61a8b89..8e9a3d6 100644
--- a/Tools/scripts/pydocgui.pyw
+++ b/Tools/scripts/pydocgui.pyw
@@ -2,4 +2,6 @@
 # importing itself (Python began allowing import of .pyw files
 # between 2.2a1 and 2.2a2).
 import pydoc
-pydoc.gui()
+
+if __name__ == '__main__':
+   pydoc.gui()
diff --git a/Tools/scripts/setup.py b/Tools/scripts/setup.py
index b36febc..23bf247 100644
--- a/Tools/scripts/setup.py
+++ b/Tools/scripts/setup.py
@@ -1,18 +1,19 @@
 from distutils.core import setup
 
-setup(
-  scripts=[
-    'byteyears.py',
-    'checkpyc.py',
-    'copytime.py',
-    'crlf.py',
-    'dutree.py',
-    'ftpmirror.py',
-    'h2py.py',
-    'lfcr.py',
-    'logmerge.py',
-    '../../Lib/tabnanny.py',
-    '../../Lib/timeit.py',
-    'untabify.py',
-    ],
-  )
+if __name__ == '__main__':
+    setup(
+      scripts=[
+        'byteyears.py',
+        'checkpyc.py',
+        'copytime.py',
+        'crlf.py',
+        'dutree.py',
+        'ftpmirror.py',
+        'h2py.py',
+        'lfcr.py',
+        'logmerge.py',
+        '../../Lib/tabnanny.py',
+        '../../Lib/timeit.py',
+        'untabify.py',
+        ],
+      )
diff --git a/Tools/scripts/suff.py b/Tools/scripts/suff.py
index dfb3da0..c026201 100755
--- a/Tools/scripts/suff.py
+++ b/Tools/scripts/suff.py
@@ -26,4 +26,5 @@
             suff = filename[i:]
     return suff
 
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/treesync.py b/Tools/scripts/treesync.py
index 1064ab7..ab9324b 100755
--- a/Tools/scripts/treesync.py
+++ b/Tools/scripts/treesync.py
@@ -201,4 +201,5 @@
     print "Yes or No please -- try again:"
     return okay(prompt)
 
-main()
+if __name__ == '__main__':
+    main()
diff --git a/Tools/scripts/which.py b/Tools/scripts/which.py
index 7b3d2e0..f9b2e61 100755
--- a/Tools/scripts/which.py
+++ b/Tools/scripts/which.py
@@ -13,44 +13,49 @@
 def msg(str):
     sys.stderr.write(str + '\n')
 
-pathlist = os.environ['PATH'].split(os.pathsep)
+def main():
+    pathlist = os.environ['PATH'].split(os.pathsep)
 
-sts = 0
-longlist = ''
+    sts = 0
+    longlist = ''
 
-if sys.argv[1:] and sys.argv[1][:2] == '-l':
-    longlist = sys.argv[1]
-    del sys.argv[1]
+    if sys.argv[1:] and sys.argv[1][:2] == '-l':
+        longlist = sys.argv[1]
+        del sys.argv[1]
 
-for prog in sys.argv[1:]:
-    ident = ()
-    for dir in pathlist:
-        filename = os.path.join(dir, prog)
-        try:
-            st = os.stat(filename)
-        except os.error:
-            continue
-        if not S_ISREG(st[ST_MODE]):
-            msg(filename + ': not a disk file')
-        else:
-            mode = S_IMODE(st[ST_MODE])
-            if mode & 0111:
-                if not ident:
-                    print filename
-                    ident = st[:3]
-                else:
-                    if st[:3] == ident:
-                        s = 'same as: '
-                    else:
-                        s = 'also: '
-                    msg(s + filename)
+    for prog in sys.argv[1:]:
+        ident = ()
+        for dir in pathlist:
+            filename = os.path.join(dir, prog)
+            try:
+                st = os.stat(filename)
+            except os.error:
+                continue
+            if not S_ISREG(st[ST_MODE]):
+                msg(filename + ': not a disk file')
             else:
-                msg(filename + ': not executable')
-        if longlist:
-            sts = os.system('ls ' + longlist + ' ' + filename)
-            if sts: msg('"ls -l" exit status: ' + repr(sts))
-    if not ident:
-        msg(prog + ': not found')
-        sts = 1
+                mode = S_IMODE(st[ST_MODE])
+                if mode & 0111:
+                    if not ident:
+                        print filename
+                        ident = st[:3]
+                    else:
+                        if st[:3] == ident:
+                            s = 'same as: '
+                        else:
+                            s = 'also: '
+                        msg(s + filename)
+                else:
+                    msg(filename + ': not executable')
+            if longlist:
+                sts = os.system('ls ' + longlist + ' ' + filename)
+                if sts: msg('"ls -l" exit status: ' + repr(sts))
+        if not ident:
+            msg(prog + ': not found')
+            sts = 1
 
-sys.exit(sts)
+    sys.exit(sts)
+
+if __name__ == '__main__':
+    main()
+
diff --git a/Tools/scripts/xxci.py b/Tools/scripts/xxci.py
index 681ce0b..c6a7d08 100755
--- a/Tools/scripts/xxci.py
+++ b/Tools/scripts/xxci.py
@@ -109,8 +109,9 @@
     s = raw_input(prompt)
     return s in ['y', 'yes']
 
-try:
-    setup()
-    go(getargs())
-except KeyboardInterrupt:
-    print '[Intr]'
+if __name__ == '__main__':
+    try:
+        setup()
+        go(getargs())
+    except KeyboardInterrupt:
+        print '[Intr]'