Avorion

Avorion is a co-operative space game where you build your own space ships out of dynamically scalable blocks.

All the content in this game is procedurally generated while the player explores; wherever you go, you will always find new places, ships and factions. You're free to do everything you want to: Explore, mine, trade, help others, build up an army, go to war, be a pirate, or raid helpless freighters.