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.
Battle Just Started is 3D arcade tank battle game. Rendering is done using OpenGL, and direct rendering is recommended. The game is focused on multiplayer over LAN. An AI is also present, but is not very strong. World simulation is done via ODE, and sound is done using OpenAL and SDL_mixer. The game has currently 6 maps, 5 tanks, and 4 weapons.