This is a patched version of the Quake2 Engine from http://icculus.org/. It hasn't been updated in a while, and as such has lots of compatibility issues with the latest OS's. I started with an svn checkout and began patching it with numerous different patches until it ran on my machines.
It also has some changes to allow building on PPC64 machines, although this is still experimental
NOTE: For PPC64, the normal quake executable has been disabled, due to issues with alsa sound. sdlquake will be built by default instead.
Tested Systems:
Dell Inspiron 1764
Debian Squeeze x86_64
kernel: 3.2.1 custom
i5-430M, 1 pp, 2 core, 4 thread, 2.27ghz, 4GB DDR3
Intel Integrated Graphics
Status: Seemingly perfect
Dell Latitude D600
Debian Squeeze i386
kernel: 3.2.7 custom
Pentium M, 1 pp, 1 core, 1 thread, 1.8ghz, 2GB DDR
Status: Seemingly perfect
PowerMac G5
Debian Squeeze ppc64
kernel: debian stock
PowerPC 970FX, 2pp, 1 core, 2 threads, 1.8ghz, 2.5GB DDR
Status: Beta
I've begun modifying the Quake-2-tools package under the SDK directory. It currently builds under PPC64 and I haven't had time to test on anything else.