Few days ago i downloaded a wonderfull application which is a multiplatform applications. There are Linux version, Windows version, and Mac OS X version. The application is called Stellarium. It's a free open source planetarium application that can be used to see a realistic sky in 3D, just like what you see with the naked eye, binoculars or a telescope. With this application, you can see a lot of objects, such as stars, planets, satellites, shooting stars, meteors, constellations, nebula, milky way, and many other things that we can see on the sky. It has a lot of features, such as multi language, zoom control, telescope control, and many more. This project is also listen in most active project in Sourceforge. Here are one of my screenshot of the application
This application could be used in educational purposes or private hobbies, mainly for those who enjoys learning about astronomy.