Open Path is an open source, browser-based, online RPG. It aims to be the best gameengine available, boasting many inbuilt features that most frameworks don't have. It is fast, powerful, robust, and free (speech and beer).
A PHP 5 library for querying game servers. Currently supporting over 160 games, including source (half-life), unreal and quake engine games, ase & gamespy protocols. Newer games supported are Crysis & Call of Duty 5. Also supports Teamspeak 2.