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.
Gomoku.app is an extended TicTacToe game for GNUstep. You win the game if you are able to put 5 of your pieces in a row, column, or diagonal. You lose if the computer does so before you. You can play the game on boards of different size. The game has 6 different difficulty levels.
ics.el is a comint based Emacs major mode for handling the text portion of communications with internet chess servers such as FICS and ICC. It is written in Emacs-Lisp and works best in conjunction with a graphical interface such as Xboard. It handles colour highlighting and "buttonisation" (making certain portions of text active so that, for example, you can challenge opponents with a single mouse click) as well as command recall and editing and automation of commands based on regexps seen in the ICS output, all highly customisable using Emacs lisp.
JACL is an interpreted language for creating interactive fiction and turn-based Web games. Using a variety of Glk libraries, JACL has cross-platform support for graphics and sound in the desktop environment. JACL also includes an integrated Web server for easy testing of Web-based games.