Textmode Quake 2
Artemis writes: "Following the Quake 2 source code release under the GPL, here's the follow-up of the famous ttyquake, it's a text mode Quake II called aaquake2 which has just been released. Time for more 3d text mode gaming fun! The site includes screenshots for those of you who haven't seen Quake-turned-Text before."
The link above seems to be slashdotted, try this one.
Apparently, that's the way the initial port of X-Windows to Linux was done - instead of driving the graphics card, it just used the terminal. Who knows if the code is around anywhere, though.
It's a window manager for your terminal. http://linuz.sns.it/~max/twin/
Why not? You can watch TV in text mode, you can play DVDs in text mode,
you can play Quake 1 in text mode. Quake II is the logical next step.
Or, as the author of ttyquake put it, "If you have to ask why, you're not a member of the intended audience."
Some fool compiled an xserver with aalib and you can see the output including screenshots of enlightenment menus etc here:
http://www.meow.org.uk/stan/xserver/
Maybe that'd work with xquake?