Spaceward Ho

Spaceward Ho, already a classic in the Mac world, has been rereleased for Mac OS X. In this game, you control the entire military and economy of a space-faring race.

Your goal: explore and colonize the galaxy. Unfortunately, you are not alone in your imperialist endeavors. Alien enemies bent on galactic conquest will oppose your expansion. You fight them by developing new technologies and expanding your empire, or you can ally with them to turn enemies into friends.
Terraform newly discovered worlds or mine their natural resources. Maneuver your starship fleets, both in defense of your own systems and in offensive strikes against the evil aliens. Your strategic decisions will determine the fate of the galaxy. Play alone against the computer or against other humans over the Internet.