Battle for Wesnoth
The Battle for Wesnoth, or simply Wesnoth, is a free turn-based strategy game designed in June 2003 by David White.
David White based Wesnoth on the Sega Genesis games Master of Monsters and Warsong (also known as Langrisser). He wanted to create a freely-available, open source strategy game that had very simple rules, but had a strong artificial intelligence, and was challenging and fun.
The current stable release of the game is 1.4.5, released on September 2, 2008. The Battle for Wesnoth is cross-platform, so it is available for a variety of different operating systems. Released under the GNU General Public License, The Battle for Wesnoth is free software.