ETXreaL is a new engine that's paired with the original id Software Enemy Territory game assets. The improved open-source engine offers 64-bit support, an OpenGL 3.2 renderer, OpenGL VBO (vertex buffer object) changes, true 64-bit HDR lighting, deferred shading, real-time sun lights, relief mapping, and many other visual features not found in the original id Tech 3 engine with Return to Castle Wolfenstein: Enemy Territory.