Stellarium, Stellarium review can show the sky

It's a great open source program that can show the sky high, with information on about 120000 stars (including constellations, planets, etc.).. Shows a realistic sky in 3D perspective, simulating the visual to the naked eye, binoculars or telescope. It can see the sky is the atmosphere that without (the visual atmosphere is nice, but if you want to see the stars you may need to disable it), and have information about distant stars (magnitude, distance, category, spectral) simply clicking on them. The zoom allows you to go see the selected celestial body as if you were using a telescope.

Very very nice.

Stellarium