*** modified file 'bzrlib/commands.py'
--- bzrlib/commands.py 
+++ bzrlib/commands.py 
@@ -721,10 +721,11 @@
     """
     
     takes_args = ['file*']
-    takes_options = ['revision', 'diff-options']
+    takes_options = ['revision', 'diff-options', 'ndiff']
     aliases = ['di', 'dif']
 
-    def run(self, revision=None, file_list=None, diff_options=None):
+    def run(self, revision=None, file_list=None, diff_options=None,
+            ndiff=None):
         from bzrlib.diff import show_diff
 
         if file_list:
@@ -735,9 +736,15 @@
                 file_list = None
         else:
             b = find_branch('.')
-    
+
+        if ndiff:
+            format = 'ndiff'
+        else:
+            format = None
+
         show_diff(b, revision, specific_files=file_list,
-                  external_diff_options=diff_options)
+                  external_diff_options=diff_options,
+                  format=format)
 
 
         
@@ -1344,6 +1351,7 @@
     'format':                 unicode,
     'forward':                None,
     'message':                unicode,
+    'ndiff':                  None,
     'no-recurse':             None,
     'profile':                None,
     'revision':               _parse_revision_str,

*** modified file 'bzrlib/diff.py'
--- bzrlib/diff.py 
+++ bzrlib/diff.py 
@@ -70,6 +70,13 @@
     print >>to_file
 
 
+
+def internal_ndiff(old_label, oldlines,
+                   new_label, newlines,
+                   to_file):
+    """Show diff in python-specific ndiff format."""
+    from difflib import ndiff
+    to_file.writelines(ndiff(oldlines, newlines))
 
 
 def external_diff(old_label, oldlines, new_label, newlines, to_file,
@@ -152,7 +159,8 @@
     
 
 
-def show_diff(b, revision, specific_files, external_diff_options=None):
+def show_diff(b, revision, specific_files, external_diff_options=None,
+              format=None):
     """Shortcut for showing the diff to the working tree.
 
     b
@@ -160,6 +168,9 @@
 
     revision
         None for each, or otherwise the old revision to compare against.
+
+    format
+        'unified', 'context', 'ndiff', 'external'
     
     The more general form is show_diff_trees(), where the caller
     supplies any two trees.
@@ -174,12 +185,13 @@
     new_tree = b.working_tree()
 
     show_diff_trees(old_tree, new_tree, sys.stdout, specific_files,
-                    external_diff_options)
+                    external_diff_options, format)
 
 
 
 def show_diff_trees(old_tree, new_tree, to_file, specific_files=None,
-                    external_diff_options=None):
+                    external_diff_options=None,
+                    format=None):
     """Show in text form the changes from one tree to another.
 
     to_files
@@ -204,10 +216,12 @@
     if external_diff_options:
         assert isinstance(external_diff_options, basestring)
         opts = external_diff_options.split()
-        def diff_file(olab, olines, nlab, nlines, to_file):
+        def diff_fn(olab, olines, nlab, nlines, to_file):
             external_diff(olab, olines, nlab, nlines, to_file, opts)
+    elif format == 'ndiff':
+        diff_fn = internal_ndiff
     else:
-        diff_file = internal_diff
+        diff_fn = internal_diff
     
 
     delta = compare_trees(old_tree, new_tree, want_unchanged=False,
@@ -216,7 +230,7 @@
     for path, file_id, kind in delta.removed:
         print >>to_file, '*** removed %s %r' % (kind, path)
         if kind == 'file':
-            diff_file(old_label + path,
+            diff_fn(old_label + path,
                       old_tree.get_file(file_id).readlines(),
                       DEVNULL, 
                       [],
@@ -225,7 +239,7 @@
     for path, file_id, kind in delta.added:
         print >>to_file, '*** added %s %r' % (kind, path)
         if kind == 'file':
-            diff_file(DEVNULL,
+            diff_fn(DEVNULL,
                       [],
                       new_label + path,
                       new_tree.get_file(file_id).readlines(),
@@ -234,7 +248,7 @@
     for old_path, new_path, file_id, kind, text_modified in delta.renamed:
         print >>to_file, '*** renamed %s %r => %r' % (kind, old_path, new_path)
         if text_modified:
-            diff_file(old_label + old_path,
+            diff_fn(old_label + old_path,
                       old_tree.get_file(file_id).readlines(),
                       new_label + new_path,
                       new_tree.get_file(file_id).readlines(),
@@ -243,7 +257,7 @@
     for path, file_id, kind in delta.modified:
         print >>to_file, '*** modified %s %r' % (kind, path)
         if kind == 'file':
-            diff_file(old_label + path,
+            diff_fn(old_label + path,
                       old_tree.get_file(file_id).readlines(),
                       new_label + path,
                       new_tree.get_file(file_id).readlines(),