Sid Meier's Alpha Centauri

From the publisher's Web site:

Sid Meier's Alpha Centauri, FIRAXIS' second title, was released in February 1999. This epic science fiction turn-based strategy game takes Sid's legendary gameplay into the 22nd century, offering the perfect balance of exploration, discovery, empire building and conquest. Since its release, Alpha Centauri has become one of the best-selling games around the world. In September 1999, FIRAXIS further enhanced the Alpha Centauri experience with the release of Sid Meier's Alien Crossfire, nominated for 1999 "Expansion Pack of the Year".

Explore the alien planet that is your new home and uncover its myriad mysteries. Discover over 75 extraordinary technologies. Build over 60 base upgrades and large-scale secret projects for your empire. Conquer your enemies with a war machine that you design, using over 32,000 possible units.