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.
Overflow is a board game for two players or one player against the computer. Put pieces on the board until critical mass is reached, and watch a chain reaction go off. Although the rules are simple, several different tactical considerations are required in order to play the game well.
The Python/Tk Empire Interface (PTkEI) enables you to connect to empire 4.x.x (Wolfpack) servers. Empire is a real-time war game with long tradition. You can find out about Empire and currently running servers and other clients at its homepage. This client is an example for a truly portable cross-platform GUI, known to run on Unix, X11, Win32 and Mac. Additionally you do not give up any command line power as a player, but you have to to learn the empire commands to make use of this GUI client.