With this modMegatexture was in the Doom 3 engine, but it was broken and unfinished. Now a modder has finished it and got it working in the default Doom 3 engine! This includes Doom 3, Prey, and Quake 4.
The mod is really just a large terrain to check out. Its not as nice as what will be in Quake Wars because the QW version has been updated significantly. But if you've got any of the 3 games above still installed, you can check it out for yourself.
