Vega Strike un jeu libre d'économie et exploration spatiale qui a l'air vraiment sympa d'après wikipédia :
http://fr.wikipedia.org/wiki/Vega_Strike
Vega Strike is an Open Source 3D Action-Space-Sim that lets you trade, fight, and explore in a vast universe.
Vega Strike is built on top of OpenGL and runs on Win/Lin/Mac platforms. Vega Strike (the game) is currently in a playable state, but both game engine and dataset are under continued development
via : http://linuxfr.org/users/chimrod/journaux/oolite-un-pare-feu-dans-l-espace#comment-1606213