The PHP Unit Testing framework.

A PHP parser written in PHP

Event-driven, non-blocking I/O with PHP.

Learning and Using ØMQ

Sample Application built with Backbone.js and 3 different UI toolkits: Twitter Bootstrap, jQuery Mobile, and custom iPhone skins

Benchmarks and test code for The Great Web Framework Shootout [DEPRECATED -- See techempower's benchmarks instead]

The Appleseed Project - The First Open Source+Distributed Social Networking Platform

Storm Multilang support with PHP [INACTIVE]

Nuclear Reactor written in PHP.