Free drawing software for Windows, Mac OS X, and Linux
Dia Diagram Editor is free Open Source drawing software for Windows, Mac OS X and Linux. Dia supports more than 30 different diagram types like flowcharts, network diagrams, database models. More than a thousand readymade objects help to draw professional diagrams. Dia can read and write a number of different raster and vector image formats. Software developers and database specialists can use Dia as a CASE tool to generate code skeletons from their drawings. Dia can be scripted and extended using Python.
Audio converter and CD ripper for various formats
fre:ac is a free audio converter and CD ripper for various formats and encoders. It features MP3, MP4/M4A, WMA, Ogg Vorbis, FLAC, AAC, and Bonk format support, integrates freedb/CDDB, CDText and ID3v2 tagging and is available in several languages.
A planetarium software that shows a 3D simulation of the night sky
Stellarium renders 3D photo-realistic skies in real time with OpenGL. It displays stars, constellations, planets, nebulae and others things like ground, landscape, atmosphere, etc.
A cross-platform statistical package for econometric analysis
gretl is a cross-platform software package for econometric analysis, written in the C programming language.
Educational Software for children aged 2 to 10.
GCompris is a high quality educational software suite comprising of numerous activities for children aged 2 to 10. Some of the activities are game oriented, but nonetheless still educational.