Crossfire

Crossfire is a multi-player graphical arcade and adventure game made for the X Windows systems environment. It has certain flavours from other games, especially gauntlet and the rogue-like games (Nethack, Moria, Angband, and Ragnarok.) Any number of players can move around in their own window, finding and using items and battling monsters. They can choose to cooperate or compete in the same world.''

In the years of development that have followed, Crossfire has grown to encompass over 150 monsters, ~3000 maps to explore, an elaborate magic system, over 15 character types, a system of skills, and many, many artifacts and treasures.

Crossfire is freely distributed under the GNU license and the code may be obtained from a number of FTP sites. Take note: you will need at least an ANSI C compiler (i.e. gcc) and UNIX to build the game.

http://crossfire.real-time.com/

Free massively multiplayer online games directory