NagaSkaki

NagaSkaki is a free, fully functional chess program for Windows 98, NT, XP and Vista. It is available for download and you are encouraged to distribute it to as many people as you want (as long as it's free!)

一款国际象棋游戏

Freeciv 模拟文明的程序

http://www.freeciv.org/index.php/Freeciv

一个模拟文明发展的游戏，从原始社会开始。由你来主宰这个世界。

有多个系统上的版本，Windows, MacOS, Linux

FreeCol

http://www.freecol.org/
一个殖民地模拟游戏，大富翁？
This is the homepage of FreeCol, an open source project that aims to provide a free Colonization clone (released under the GPL). A more detailed description of the original game can be found in the About section.

The Open Racing Car Simulator

“...The Open Racing Car Simulator . TORCS is a highly portable multi platform car racing simulation. It is used as ordinary car racing game, as AI racing game and as research platform. It runs on Linux (x86, AMD64 and PPC), FreeBSD, MacOSX and Windows. The source code of TORCS is licensed under the GPL ("Open Source"). ...”
一款免费的赛车游戏，开源，可以运行于多个平台上。
Download and find more info here.
http://torcs.sourceforge.net/