From Drupal and Moodle, right through to a Git versioning system and Perl modules on CPAN, we contribute back to over 175 community open source projects. This list is in order of the number of projects contributed to.
toy language exploring static verifiability
ikiwiki is a wiki compiler. It converts wiki pages into html pages suitable for publishing on a website.
Convert images to OpenSCAD contours
jQuery plugin for doing animated title sequences (eg: like movie credits)
jQuery plugin to make elements of a web page/app draggable by mouse or touch.
A bot for use with AIM, Jabber or MSN to communicate with a Koha server.
Linux home directory files
Kernel for Google/LG Nexus 4 (LG-E960)