0verkill is a client-server 2D deathmatch-like game in ASCII art. It supports free connecting/disconnecting during the game, and runs well on modem lines. Graphics are in 16-color ASCII art with elaborate hero animations. 0verkill features 4 different weapons, grenades, invisibility, and armor. The package also contains reaperbot clients, a simple graphics editor, and a level editor.
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.
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.
Neohunt is an enhanced variant of hunt, a multiplayer game in which you run around a maze and shoot your friends before they shoot you. It is also an artifact of an earlier age, to be used either as nostalgia (if you remember the eighties) or as an example of how much better things are today (if you don't).
The Castle is a first-person shooter game in a dark fantasy setting. Your main weapon is a sword, so the fight is mostly short-range. Three main levels are included, packed with creatures, items, and sounds. A couple of bonus levels are also available, like the classic DOOM E1M1 level reimplemented in VRML. The game engine is based on VRML, OpenGL, OpenAL, and all shadows are done by the shadow volumes approach.
U-Hexen is a port of the popular 3D game, Hexen by Raven Software/Id Software, to the Simple Directmedia Layer library. It uses an SDL mixer for sound and music. Some new menus were added for easier configuration. It works on Linux, FreeBSD, OpenBSD, and Windows. On FreeBSD, the game can work on the console without X.