Aciqra
A virtual planetarium for observers of the real sky.
...It includes the 2.5 million stars of the Tycho-2 catalog supplemented by data of 120,000 stars from the Hipparcos catalog, 13,000 deep space objects from the NGC and IC catalogs and a large number of asteroids and comets from the Minor Planet Center. The program is platform-independent and can be made to work on most modern computers that support OpenGL.