Various links of interest:
GenDev – A site dealing mainly with developing on the Sega Genesis/Megadrive. – Community ran forum for the game QuakeWorld.
OpenArena – GPL’d clone of Quake 3: Arena, with GPL’d assets.

Links that support MMP-Games one way or another:
OpenArena | Configs, Tips, Off-Topics, Etc. – A blog with helpful information regarding OpenArena.