Game framework including 1, 2 and multi-players modes which doesn't involve any central server, so peer-to-peer multi-players equivalent! Java environment (v. 1.5+ @ java.sun.com) Including a multi-platform API.
Imaging capabilities provided by Java Advanced Imaging (JAI) and 3D support provided by the LWJGL (www.lwjgl.org) API.
Havoc is a python game power by pygame. A bidimensional old school shot'em up with an improved ai, different weapons and different kinds of enemies with different abilities.
Tank Arena X is a 2-D arcade game playable by a single or multiple players. It loads all the game data from simple text files, allowing for easy modifications and creation of new levels and mods. Also, can support AI tanks using its AI engine.