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.
Babelize is a collection of localizations for Linux games. It currently features French, German, Polish, and Spanish translations for "Heroes of Might and Magic III", as well as French, German, and Spanish translations for "Alpha Centauri - Alien Crossfire". The goal of the project is to provide localizations for as many native Linux games as possible.
Chaotic Domain aims to revolutionize the RTS industry. Made up a team of "elite gamers" (not to mention great programmers and 3D modelers) we're combining the greatest features we like in other strategy games, fixes for some of the "annoying" parts of those games, and many new ideas of our own. With a full 3D galaxy that allows you to micro- or macro-manage and very customizable games, it should appeal to every user.