Here is a list of some of the open source projects I am or have been involved with. Several of these projects I worked on while working at Three Rings Design, so thanks to them for supporting open source software development!
FreeBSD
I am a source committer and have worked on the FreeBSD kernel, userland, and ports system. Recently I worked on adding a low memory event handler for dirhash, a directory indexing subsystem for the UFS2 filesystem, as part of the 2008 Google Summer of Code. I did a talk about this at EuroBSDCon 2008 in Strasbourg, France. Slides and ogg audio are available for download.
Some other FreeBSD stuff I have worked on includes working with Landon Fuller to add interface cloning support for the tun(4) and tap(4) network devices. I have submitted a number of small userland and ports patches, as well as maintaining several ports myself. Finally, I have written a few security advisories for ports that have been added to the VuXML vulnerability database. Some of the things I'm working on now or plan to in the near future can be found in my .plan file.
labench
I recently started this project to do some performance measurements of different implementations of the linear algebra libraries BLAS and LAPACK. On a given system, different libraries providing BLAS and LAPACK routines may have substantially different performance based on how they are tuned for that particular hardware. It is useful to measure this performance to help decide library to use on the hardware one has available. labench is quite basic now, but I hope to expand its capabilities in the future.
Splat
Splat is the Scalable Periodic LDAP Attribute Transmogrifier. Splat is a daemon that keeps information in an LDAP directory synched with outside data. In addition to fixing bugs and writing documentation, I have written plug-ins for creating home directories as well as archiving and purging home directories for LDAP accounts that have been disabled.
Farbot
Farbot automates the creation of a network install environment for FreeBSD. I did a major simplification of the farbot code base, removing its unneeded dependence on the event-driven Twisted framework. I also added the ability to use binary ISOs for releases and other small features and bug fixes.
Quercus LDAP
I wrote some of of PHP's LDAP functions for Quercus, a Java implementation of PHP 5. As of this writing, I believe these functions are still unavailable in the Quercus distribution, but my source code is available for download here. Many of PHP's LDAP functions are missing, but there should be enough implemented in my library to support authentication via binding to an LDAP server in a PHP application running under Quercus.
Ubuntu
I created and maintain the splatd package, and created and previously maintained the drawterm package.