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.
You are captain of the cargo ship Chromium B.S.U., responsible for delivering supplies to our troops on the front line. Your ship has a small fleet of robotic fighters which you control from the relative safety of the Chromium vessel. Chromium B.S.U. is a fast paced, arcade-style, top-scrolling shooter. It uses OpenGL for graphics, OpenAL/SDL_mixer for sound effects, GLC/FTGL for text rendering, and glpng/SDL_image for texture loading.
Tux Paint is a simple and entertaining drawing program geared towards young children. It has a simple interface, sound effects, and a cartoon character (Tux, the Linux penguin). Along with drawing brush strokes, lines and shapes, you can also enter text and place "rubber stamp" (or "sticker") images on the picture. Tux Paint is extensible, and could be useful in an educational environment (such as a grammar, elementary, or grade school). It's portable across numerous platforms, and runs well even on slower systems like the Pentium 133MHz.
TuxWordSmith is similar to the classic word game "Scrabble", but with Unicode support for multiple languages and character sets. The game is currently distributed with 42 dictionary resources for playing Language[i]-Language[j] "Scrabble". For example, if configured to use the French-German dictionary, then the distribution of available tiles will be computed based on frequency of occurrence of each character of Language[i] (French), and, for each submission, the corresponding definition will be given in Language[j] (German).
Mtp Target is a multi-player online action game working on Windows, Linux and Mac where you fight with and against players. It's a mix of action, dexterity, and strategy game. After rolling down a giant ramp, you must delicately land your avatar on the platform that will reward you with the most points. With your friends, you can set up strategies to eject the other players off the platforms in order to score maximum points.