I currently work for Collabora on various open-source projects. The main one is Telepathy, a presence, messaging and voice/video over IP framework based on D-Bus; it's used on Nokia's Maemo devices (notably the N900, which even uses it for phone calls), on the GNOME desktop (via Empathy), on One Laptop Per Child, and elsewhere.
I mainly work on the API specification, Mission Control (the reference implementation of an account manager and channel dispatcher), and the GObject binding telepathy-glib; I've also contributed to the Qt4 and Python bindings and to most of the connection managers.
Current personal projects
I sporadically contribute to IkiWiki, the wiki compiler used by this website (including various plugins and some significant performance improvements), and do various QA work in Debian (fixing release-critical bugs and asking for the removal of redundant packages).
Various old projects
The Paradox Productions section contains some old game modifications, some with source code.
Other old projects include runit scripts for Debian (runit is a GPLed init(8) replacement similar to daemontools), and a GUI Photo Indexer done for the programming component of my A-Level Computing coursework.