I can’t remember if I posted about Stellarium before. Sorry for a repost if I have.
Stellarium is one of the coolest open source projects out there. In fact, I’m not sure how good a commercial version of this would actually be. Some things are just better as academic and labor of love efforts.
If you like star gazing, deep space imaging, telescopes and generally “where are we in the universe” stuff, download this thing and play with it.
I love Stellarium. Another awesome open source project along the same vein: Celestia. Not all that great for amateur stargazing, but being able to fly through space is just plain cool.