diff --git a/dev-tools/scripts/diffSources.py b/dev-tools/scripts/diffSources.py
new file mode 100644
index 00000000000..8318f241cd5
--- /dev/null
+++ b/dev-tools/scripts/diffSources.py
@@ -0,0 +1,61 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import subprocess
+import sys
+
+# recursive, unified output format, treat missing files as present but empty
+DIFF_FLAGS = '-ruN'
+
+if '-skipWhitespace' in sys.argv:
+  sys.argv.remove('-skipWhitespace')
+  # ignores only whitespace changes
+  DIFF_FLAGS += 'bBw'
+
+if len(sys.argv) != 3:
+  print
+  print 'Usage: python -u diffSources.py <dir1> <dir2> [-skipWhitespace]'
+  print
+  print '''This tool creates an applying patch between two directories.
+
+While you could use this to make a committable patch from a branch, that approach loses
+the svn history from the branch (better to use "svn merge --reintegrate", for example).  This
+diff output should not be considered "authoritative" from a merging standpoint as it does
+not reflect what svn will do on merge.
+'''
+  print
+  sys.exit(0)
+
+p = subprocess.Popen(['diff', DIFF_FLAGS, '-x', '.svn', '-x', 'build', sys.argv[1], sys.argv[2]], shell=False, stdout=subprocess.PIPE)
+
+keep = False
+while True:
+  l = p.stdout.readline()
+  if l == '':
+    break
+  if l.endswith('\r\n'):
+    l = l[:-2]
+  elif l.endswith('\n'):
+    l = l[:-1]
+  if l.startswith('diff ') or l.startswith('Binary files '):
+    keep = l.lower().find('/build/') == -1 and (l.lower().startswith('Only in') or ((l.lower().endswith('.java') or l.lower().endswith('.txt') or l.lower().endswith('.xml') or l.lower().endswith('.iml')) and l.find('/.svn/') == -1))
+    if keep:
+      print
+      print
+      print l.strip()
+  elif keep:
+    print l
+  elif l.startswith('Only in'):
+    print l.strip()