SpaceVR - Explore space with Oculus Rift (pre-launch)
Star Chart - Stellarium is a planetarium software that shows exactly what you see when you look up at the stars. It's easy to use, and free. Read more about Star Chart.
The Size of Space - An interactive visualization of the universe
Google Sky Map - Google Sky Map is a free hand-held planetarium that allows you to identify stars, planets and more.
Space Telescope - Explore the universe on Apple TV
Code NASA - 253 NASA open source software projects