1. 3D Universe Simulator OpenUniverse (OU for short) is a fun, fast and free OpenGL space simulator. It currently focusses on the Solar System and lets you visit all of its planets, most major moons and a vast collection of smaller bodies in colorful, glorious and realtime 3D. If you've ever had a chance to visit Mercury or asteroid Geographos, here you'll find them looking exactly the same way, following exactly the same path as when you've left them. From Debian 3.0r0 APT