Source Management Tools

Here are some different source management tools commonly used with
Linux:

Overview

David Wheeler has an excellent breakdown of various SCM tools at:
http://www.dwheeler.com/essays/scm.html
IBM has an good overview of available tools at:
http://www-128.ibm.com/developerworks/linux/library/l-vercon/
There is a comparison of several different tools at:
http://better-scm.berlios.de/comparison/comparison.html

diff - to create patches
- use ‘man diff’ on your local system for information
patch - to apply
patches
- use ‘man patch’ on your local system for information
Quilt is good for managing a group of patches
relative to a single source base.
diffstat reads a patch file (or standard input) and displays a
histogram of the insertions, deletions, and modifications per-file.
It is useful for reviewing large, complex patch files. It reads from
one or more input files or from standard input. If an input filename
ends with .bz2, .Z or .gz, diffstat will read the uncompressed data
via a pipe from the corresponding program.
- diffstat is included in most Linux distributions
- diffstat home
  page
- diffstat man
  page
Tim’s patch management
tools
- diffinfo and friends - a more verbose diffstat, with splitting,
  joining and comparing of patches
See also Diff And Patch
Tricks
Splash - Sony tool for managing patches (kind of
like quilt or stacked git)