Oolite is an independent interpretation and recreation of the classic game,
Elite. Oolite is a space trading and combat game, with the dangers of pirates,
police, bounty hunters, and various other hazards. The player's role is open
ended: there is no set goal other than perhaps to reach the Elite combat
rating, but the players may choose their own path through the universe.
The game is expandable, and numerous expansion packs already exist. New ships
and new missions are available for download.

You can find the getting started page here:
http://www.oolite.org/starting/