diff --git a/tools/git-obsolete-branch.py b/tools/git-obsolete-branch.py
index e3c634935b..5abd4803f1 100755
--- a/tools/git-obsolete-branch.py
+++ b/tools/git-obsolete-branch.py
@@ -1,17 +1,33 @@
 #!/usr/bin/python
+#
+# Copyright (C) 2012  Internet Systems Consortium, Inc. ("ISC")
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+# OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+# PERFORMANCE OF THIS SOFTWARE.
 
+#
 # This script lists obsolete (fully merged) branches. It is useful for periodic maintenance
 # of our GIT tree.
 #
 # This script requires python 2.7 or 3.
 #
 # I have limited experience in Python. If things are done in a strange or uncommon way, there
-# are no obscure reasons to do it that way, just plain lack of experience. :)
+# are no obscure reasons to do it that way, just plain lack of experience.
 #
 #                                                                        tomek
 
 import string
 import subprocess
+import sys
 
 class Branch:
     MERGED=1
@@ -21,7 +37,7 @@ class Branch:
     last_commit = ""
 
 
-def branch_list_get():
+def branch_list_get(verbose):
     txt_list = subprocess.check_output(["git", "branch", "-r"])
 
     txt_list = txt_list.split(b"\n")
@@ -42,7 +58,9 @@ def branch_list_get():
         branch_info.name = branch_info.name.decode("utf-8")
 
         # check if branch is merged or not
-        print ("Checking branch %s" % branch_info.name)
+        if verbose:
+            print("Checking branch %s" % branch_info.name)
+
         cmd = ["git", "diff", "master..." + branch_info.name ]
         diff = subprocess.check_output(cmd)
         if (len(diff) == 0):
@@ -66,40 +84,88 @@ def branch_list_get():
 #        return (out)
     return (out)
 
-def branch_print(branches, print_merged, print_notmerged, print_stats):
+def branch_print(branches, csv, print_merged, print_notmerged, print_stats):
     merged = 0
     notmerged = 0
+    merged_str = ""
+    notmerged_str = ""
     for branch in branches:
         if (branch.status==Branch.MERGED):
             merged = merged + 1
             if (not print_merged):
                 continue
-            print("%s,merged,%s" % (branch.name, branch.last_commit) )
+            if (csv):
+                print("%s,merged,%s" % (branch.name, branch.last_commit) )
+            else:
+                merged_str = merged_str + " " + branch.name
         else:
             # NOT MERGED
             notmerged = notmerged + 1
             if (not print_notmerged):
                 continue
-            print("%s,notmerged,%s" % (branch.name, branch.last_commit) )
+            if (csv):
+                print("%s,notmerged,%s" % (branch.name, branch.last_commit) )
+            else:
+                notmerged_str = notmerged_str + " " + branch.name
+
+    if (not csv):
+        if (print_merged):
+            print("Merged branches    : %s" % (merged_str))
+        if (print_notmerged):
+            print("NOT merged branches: %s" % (notmerged_str))
 
     if (print_stats):
         print("#----------");
         print("#Merged    : %d" % merged)
         print("#Not merged: %d" % notmerged)
 
+def show_help():
+    print("This script prints out merged and/or unmerged branches of a GIT tree.")
+    print("Supported command-line options:")
+    print("")
+    print("--csv          produce CSV (coma separated value) output")
+    print("--unmerged     lists umerged branches")
+    print("--skip-merged  do not print merged branches (that are listed by default)")
+    print("--stats        prints out statistics")
+    print("--help         prints out this help")
+
 def main():
     usage = """%prog
     Lists all obsolete (fully merged into master) branches.
     """
 
-    print("branch name,status,date,last commit(mail),last commit(name)")
+    csv = False;
+    merged = True;
+    unmerged = False;
+    stats = False;
 
-    branch_list = branch_list_get()
+    for x in sys.argv[1:]:
+        if x == "--csv":
+            csv = True;
+        elif x == "--unmerged":
+            unmerged = True;
+        elif x == "--skip-merged":
+            merged = False;
+        elif x == "--stats":
+            stats = True;
+        elif x == "--help":
+            show_help()
+            return
+        else:
+            print("Invalid parameter: %s" % x)
+            print("")
+            show_help()
+            return
+
+    if csv:
+        print("branch name,status,date,last commit(mail),last commit(name)")
+
+    branch_list = branch_list_get(not csv)
 
 #   Uncomment this to print out also merged branches
 #    branch_print(branch_list, False, True, False)
 
-    branch_print(branch_list, True, False, True)
+    branch_print(branch_list, csv, merged, unmerged, stats)
 
 if __name__ == '__main__':
    main()