XreaL is an open-source ioquake3 project I first wrote about in 2009 when it was shaping up to be the most advanced open-source game engine. While XreaL is derived from an engine that got its start more than a decade ago with Quake III Arena, the lead developer behind the project made a number of enhancements to make this engine more modern. He wrote a pure GLSL renderer and began to take advantage of OpenGL ES 2.0 and OpenGL 3.x APIs.
The graphics shown by XreaL were quite stunning, but XreaL as a game really never got off the ground since the project lacked artists to come up with interesting game assets, worthwhile game-play, etc. So XreaL basically faded off.
The source-code to id Tech 3 was released in 2005, but last year marked the release of id Software open-sourcing Return to Castle Wolfenstein and Wolfenstein: Enemy Territory. When that happened, XreaL was resurrected and work began to re-base the XreaL changes on the Enemy Territory work.
This allows Doom 3 and Quake 4 maps to be compiled for Enemy Territory, support for dynamic shadows, and various other enhancements. Like XreaL proper, the ET:XreaL project was also not quick to release. The last time I talked about XreaL was this summer when looking at the progress and also talking about a modular rendering system for ioquake3.
What I can finally say today is that a release has been tagged for the Enemy Territory version of XreaaL. It can be fetched from its SourceForge site. ETXreaL-0.3.0-20111110 was tagged last week. The game's read-me file goes through setting up ETXreaL with the Enemy Territory game assets, etc.