XreaL is a heavily improved Quake 3 Arena engine. It's bundled with new tools and a demo game that was never finished. ET:XreaL is a subproject bringing all XreaL enhancements to Return to Castle Wolfenstein: Enemy Territory.
Quake 3 Movie Maker's Edition is a special version of Quake 3 engine that aids the creation of game movies, making it possible to simplify required tasks and adds new features to the engine that are related to the movie making.
Joctree is a real-time graphics engine for Java. The engine supports scene-optimization via octrees, and will support basic model and animation formats (Wavefront/Obj and Quake/MD2).