Aleph One is a 3D first-person shooter game based on the game Marathon 2 by Bungie Software. It is set in a Sci-Fi universe dominated by deviant computer AIs and features a well thought-out plot. Aleph One was originally a MacOS game, but a cross-platform version ("Aleph One/SDL") based on the Simple DirectMedia Layer (SDL) library is currently under development which runs under Unix, BeOS, and Windows.
DeuTex is a wad composer for Doom, Heretic, Hexen and Strife. It can be used to extract the lumps of a wad and save them as individual files. Conversely, it can also build a wad from separate files. When extracting a lump to a file, it does not just copy the raw data, it converts it to an appropriate format (such as PPM for graphics, .au for samples, etc.). When it reads files for inclusion in pwads, it does the necessary reciprocal conversions. In addition, DeuTex has functions such as merging wads, etc.
Dreams Eternal is an FPS game that focuses on a strong story line and puzzle solving. It is set in the dream world. The very short summary of the story is that a scientific experiment went wrong and everybody is stuck in the dream world. You have to end this experiment by hopping from dream to dream. In every dream you have to find clues to try to find out how the experiment can be aborted.
HLmaps is a pair of Perl/CGI scripts for Half-Life game servers running on Linux, FreeBSD, and WinNT. It allows Web site visitors to view all your loaded maps, screen shots, download links, and some file statistics in a nice, sortable table. It optionally uses MySQL as the interim data store.
Doom was the classic 3D shoot'em'up game from id Software. PrBoom is a game engine for playing Doom levels, which runs on both Windows and Linux/Unix systems. It uses the SDL graphics library. PrBoom a very faithful Doom port, with great effort taken to be compatible with as many original Doom levels and demos as possible.
Q2Java is a game DLL for Quake2 that allows game code to be written in Java instead of C. It currently runs on Win32, Solaris, and Linux platforms. It takes advantange of many Java features including security, cross-platform binary compatibility, internationalization, dynamic classloading, just to name a few things.