Our lab also has a 24 monitor display wall, and as you can see from the pictures below, I got Quake 3 running on it. The system is driven by 12 linux servers (2 monitors per server) using Distributed Multihead X (DMX) and Chromium. Chromium distributes the OpenGL rendering from the head node to all of the servers. The game runs fairly fast, though some lighting effects had to be turned off and Chromium is having some trouble with the mouse.

Click for more images of the setup, as well as 9 HD monitors running Warcraft II in 3840x2160.

Source: plastk.net