DooM Legacy is an enhanced port of Doom, the classic first-person shooter from iD Software. It features high screen resolutions, an OpenGL renderer, fullscreen modes under X, client-server architecture for up to 32 players on IP-networks, Quake-style keybindings, a console, and more. It is available for Linux, DOS, and Win32.
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.
World Foundry is a 3D level game engine and asset production pathway with over 170,000 lines of code. It was originaly created as a commercial product, but is now being released under the GPL. The engine was designed from the beginning to be cross platform, and ran on Windows (DirectX, GL), and the Sony Playstation. The production pathway ran on Windows, and extended 3DStudio Max to be our level editor. The engine is currently being ported to Linux (it runs, but needs work), with plans to port the production pathway as well. Developers are wanted to help with this effort.
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.
BZFlag is a 3D, multiplayer, tank battle zone, capture the flag game that pits players against each other in a networked environment. It runs on Windows 95/98/NT/2000, Linux, MacOS 10.x, Irix, Solaris, and others. An OpenGL accelerator is highly recommended, but it is playable with 3D in software.