writebackup: Write subsequent backups of the passed file(s) with a '.YYYYMMDD[a-z]' file extension as a primitive, small and self-contained alternative to revision control systems. Implemented in VBScript and Bash.
Linklint: Enhancements, bugfixes and updates to an open source Perl program by James B. Bowlin that checks links on websites.
OLPC XO laptop: Enhancements, patches and customizations to the "100 Dollar laptop". These aren't intended for the core recipients of the laptops, small children in developing countries, but rather for Linux users and software developers who have acquired one of those laptops through the XO Giving (a.k.a. Give One, Get One) program, as I have done.
AutoHotkey scripts: AutoHotkey scripts to tweak the Windows experience for heavy keyboard power users.