A minimal WordPress theme, the same that powers this site, that includes post format support, a responsive layout, and more. You can download the project from GitHub.
A WordPress plugin for tracking which books you read. It uses a custom post type for books with a custom taxonomy for authors. The project is hosted on GitHub.
In the past I’ve also contributed to Edit Flow, created a WordPress-powered Twitter archive, and made WordPress act like a Daring Fireball-style linkblog. In college my favorite non-code project involved petitioning the Politics department at Whitman College to allow a web-only senior thesis.