Stellarium - Stellarium is a free open source planetarium for your computer.
KStars - KStars is a Desktop Planetarium for KDE.
SkySafari - SkySafari is a powerful planetarium that fits in your pocket.
Solar System Scope - 3D model of the Solar System and night sky in real time
Star Walk - Star Walk – Sky View: Explore the Stars.
Star Walk 2 Free - Star Walk 2 Free is a sumptuous planetary application that is turning out to be a great tool in identifying the objects in the night sky.