Space Engine is a procedural universe generator and exploration simulator that allows you to view incredible scenery and explore the vastness of space right from your own computer! You can fly around the universe at any speed, observing galaxies, stars, planets, nebulae, and even exotic stellar objects like black holes, pulsars, and neutron stars! The developer has also expressed wishes to integrate the ability to find randomly generated astro-engineering constructs (Think Halo, or Ringworld. Dyson Spheres are in this category as well.) Every planet in the simulation is unique, having been procedurally generated each time you explore the same system. The game also contains real systems, objects, and planets. This means you can explore nearby star systems, as well as those we may not even have discovered yet! You can approach planets to view their landscapes from the surface as well!
Space Engine's interface is extremely easy to use. Just click where you want to go, and press 'g' to move to it! Double tap the 'g' key to travel faster. You can also move your viewpoint using the WASD keys and mouse.
Just remember that it's still in beta, so a lot of features are upcoming, and it does still have some bugs to work out! (I miss the giant perfectly cubic star clusters myself )
Screenshots (Images shamelessly stolen from the thread):
Feel free to post your own screenshots here!
Newest version is 0.95
Download Guide for the Russian Site (Possibly outdated):