Developers of an open-source educational piece of software called Stellarium.
Windows version of an open-source planetarium. It shows a realistic sky in 3D, just like what you see with the naked eye, binoculars or a telescope.
Linux version of an open-source planetarium. It shows a realistic sky in 3D, just like what you see with the naked eye, binoculars or a telescope.
Mac OS X version of an open-source planetarium. It shows a realistic sky in 3D, just like what you see with the naked eye, binoculars or a telescope.