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.
CounterStrike2 is an advanced version of the popular Counter-Strike Mod for Half-Life. It is based on Xeno3D, a new 3D graphics realtime engine designed for FPS games.