The best open source software in the category Home & Education:
Stellarium
Stellarium renders 3D photo-realistic skies in real time with OpenGL. It displays stars, constellations, planets, nebulas and others things like ground, landscape, atmosphere, etc.
Celestia
Celestia is an application for real-time 3D visualization of space, with a detailed model of the solar system, over 100,000 stars, more than 10,000 galaxies, and an extension mechanism for adding more objects.
Tux Paint
A drawing program for young children with sound effects, a cartoon character, and fun 'rubber stamp'/'stickerbook' pictures.
Scribus
Scribus is an open-source program that brings professional page layout to Linux/Unix, MacOS X, OS/2 and Windows.Scribus supports professional features, such as CMYK color, spot color, separations, ICC color and robust commercial grade PDF.
