Freeciv is a multiuser reimplementation for Unix/X of the famous Microprose game of Civilization. By default, the game is an improved Civ II, but this can be customized; modpacks for near-100% compatibility with Civ I and Civ II are included. Multiuser gameplay is real-time: in each turn, all human players move concurrently. The game is designed to remain fairly playable even on poor network connections. Freeciv can also be played on standalone machines, and its AI players are a good challenge for beginners. The source code comes with the server, two X clients, and non-X clients for MS Windows and Amiga. Freeciv is released under the GNU General Public License. It is maintained by an international team of coders and enthusiasts, and is easily one of the most fun and addictive network games out there.
Empire is a game that is played against human opponents over a computer network. It is possible for a game to last from a few hours to many months. While the common goal of an Empire player is to win, there is no clear-cut definition of what winning is. Players may seek to achieve whatever goals they want to achieve.
Atanks is a multi-platform Scorched Earth clone similar to the Worms series of games. Annihilate the other tanks to earn money, then spend it on bigger and better shields and weapons to wipe out the opposition. It features a wide array of weapons, AI players, destructible landscape, weather, parachutes, teleports and a wide range of other features.
UFO: Alien Invasion is a squad-based tactical strategy game in the tradition of the old X-COM PC games, but with a twist. This game combines military realism with hard science-fiction and the weirdness of an alien invasion. The carefully constructed turn-based system gives you pin-point control of your squad while maintaining a sense of pace and danger. The story is set in the year 2084. You control a secret organization charged with defending Earth from a brutal alien enemy.
TEG is clone of 'Plan Tactico y Estrategico de la Guerra', which is a clone of Risk, a networked multiplayer turn-based strategy game. TEG is not fully compliant with Risk; some rules are different. It has a server, a robot, a GNOME client, support for GGZ Gaming Zone, and IPv6.
XBoard is a graphical chessboard for X that can serve as a user interface to play against any of a variety of chess engines that run on your local machine, or against human or computer opponents on an Internet chess server. XBoard can also be used by itself to read and write game files in PGN (portable game notation). WinBoard is a port of XBoard to Microsoft Win32.