This is the greatest game in the world.
WIKIPEDIA DON'T FAIL ME NOW.
Sid Meier's Alpha Centauri (sometimes abbreviated to SMAC or Alpha Centauri) is a 4X turn-based strategic computer game created by Brian Reynolds and Sid Meier under the auspices of Firaxis Games in 1998. It is based on a fictional attempt by human beings to colonize a planet in the Alpha Centauri star system. It picks up where Meier and Reynolds' earlier titles, Civilization I and Civilization II, left off. An expansion pack called Sid Meier's Alien Crossfire (aka SMACX or just SMAX) was also released. Although being popular with gamers and critically acclaimed, the game never reached the heights of success of the Civilization games. Pre-patched versions of Alpha Centauri and Alien Crossfire were later bundled together in the Alpha Centauri Planetary Pack. The game has also been released under the Sold-Out Software label.
This game is awesome. If you like turn based strategy games.. get it.