Stendhal is a multiplayer online adventure game (MMORPG) developed using the Arianne game development system. It features a rich and expanding world in which you can explore towns, buildings, plains, caves, and dungeons. You will meet NPCs and acquire tasks and quests for valuable experience and cold hard cash. Your character will develop and grow, and with each new level up become stronger and better. With the money you acquire, you can buy new items and improve your armour and weapons. You can also roam the world in search of evil monsters (and kill them).
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.
GNUSTEP Live CD contains a lot of software for GNUstep, a free implementation of the OPENSTEP framework (which is also directly used in Mac OS X as Cocoa). It includes excellent applications for RAD (GORM and ProjectCenter). The CD is available for i486, AMD64, Apple Mac PowerPC, and Sun UltraSPARC computers.
MudMagic Mud Client is a GTK/GNOME multi-platform MUD client. It provides aliases, triggers, multiple connections, plugins, MCCP, ZMP, MSP, tabbed sessions, ANSI color, and a game list that can be updated from mudmagic.com. It is configurable on a per-session basis. Plugins include an automapper, database, and note pad.