Open Source Software
Listed here is only (some of the) free and open source some software I've worked on. (Obviously, I've worked on a lot of commercial software not listed here.)
SkinnyMVC is a light-weight implementation of the model-view-controller architecture. Unlike many other MVC frameworks that add a baggage of code complexity and tools that are not an integral part of the MVC pattern, SkinnyMVC provides light-weight code and lots of freedom and flexibility for the PHP developer.
Go Porter Stemming is a native Go clean room implementation of the Porter Stemming Algorithm. This algorithm is of interest to people doing Machine Learning or Natural Language Processing (NLP).
WP-BloggingHeads is a WordPress plugin that makes it so BloggingHeads URLs in a post automagically get turned into flash video players, similar to how YouTube URLs in a post automafically get turned into flash video players.
VideoPress is a collection of Free and open source plugins for WordPress, geared towards video blogging and Internet TV. The VideoPress plugins are part of Show in a Box.