A planetarium software that shows a 3D simulation of the night sky
Stellarium renders 3D photo-realistic skies in real time with OpenGL. It displays stars, constellations, planets, nebulae and others things like ground, landscape, atmosphere, etc.
0 A.D. is a free, open-source, cross-platform real-time strategy game.
0 A.D. (pronounced "zero ey-dee") is a cross-platform real-time strategy (RTS) game of ancient warfare. It's a historically-based war/economy game that allows players to relive or rewrite the history of ancient civilizations, each depicted at their peak of economic growth and military prowess.
Open source FPS/RTS Game
Unvanquished is a fast-paced, futuristic FPS with RTS elements, pitting technologically advanced humans against hordes of highly adaptable aliens. The player can choose from either team, providing a fresh gameplay experience on both sides of the conflict. The game is under highly active development, with a new alpha release being made at the beginning of each month.
Hardcore 3D space shooter with spaceship upgrade possibilities.
AstroMenace is an astonishing hardcore scroll-shooter where brave space warriors may find a great opportunity to hone their combat skills. Gather money during the battle to spend them on turning your spaceship into an ultimate weapon of mass destruction and give hell to swarms of adversaries. Enjoy the wonderfully crafted 3d graphics and high-quality special effects along with a detailed difficulty adjustment and a handy interface of AstroMenace.