Last week Nexuiz 2.5 was released and we said it raised the bar for open-source gaming as it already offered impressive graphics and this new release was greeted by various engine improvements, new models, and over 3,000 other changes. Well, Nexuiz is not the only open-source first person shooter striving for perfection even without the backing of a major game studio. A relatively unheard of game engine is XreaL, which has not had a stable release yet but its lead developer claims that it is definitely the most advanced open-source game engine.
We first heard about XreaL about a year ago, but it is gone mostly under the radar. It sounded promising at first, but like so many open-source projects, they often end up being ill-maintained and fade away as quickly as them come. However, we were ecstatic to learn a few days ago that the XreaL project is still along and that this engine is growing to become quite an interesting engine for first person shooters. XreaL is in turn based upon the open-source id Tech 3 (Quake 3: Arena) engine, but so many changes have since been made that no longer makes it look like an engine from years ago.
The lead developer of XreaL is Robert Beckebans, who has been working to deliver stunning graphics capabilities to the id Tech 3 engine. As far he knows, XreaL is actually the only Quake-based engine with a pure GLSL (GL Shading Language) renderer. With his GLSL renderer for XreaL, he wrote it entirely against the OpenGL 2.0 ES specification, so that it is very minimalist in order to avoid driver problems. With OpenGL 3.x now available, he has been heavily targeting OpenGL 3.1 support. That is right, there are no commercial games on Linux yet with OpenGL 3.0/3.1 support, but XreaL has an open-source answer. XreaL also has a true 64-bit HDR rendering pipeline.