Wikipedia
Stellarium is an open source free software planetarium, licensed under the terms of the GNU General Public License, available for Linux, Windows and Mac OS X. A port Stellarium called Stellarium Mobile is available for Android, iOS & Symbian as a paid version, being developed by Noctua Software. It uses OpenGL to render a realistic projection of the night sky in real time.
Stellarium was created by the French programmer Fabien Chéreau, who launched the project in the summer of 2001. Currently, Stellarium is being maintained and developed by Alexander Wolf, Georg Zotti, Marcos Cardinot, Guillaume Chéreau, Bogdan Marinov, Timothy Reaves, Ferdinand Majerech and Jörg Müller. There are a number of other developers who contributed with the development of Stellarium, that includes Robert Spearman, Johannes Gajdosik, Matthew Gates, Nigel Kerr, and Johan Meuris, who is responsible for the artwork.
Stellarium was featured on SourceForge in May 2006 as Project of the Month.
A stellarium is a three-dimensional map of the stars, typically centered on Earth. They are common fixtures at planetariums, where they illustrate the local deep space out to perhaps 50 light years. Older examples were normally built using small colored balls or lights on support rods (painted black to make them less obvious), but more recent examples use a variety of projection techniques instead.