open source

Nettalk is a powerful but easy to use free (open source) IRC-client for Windows.

A simple open source Java editor, created for who wants to learn Java.

Dovecot is an open source IMAP and POP3 server for Linux/UNIX-like systems

Dovecot is an open source IMAP and POP3 server for Linux/UNIX-like systems

APE is a free AS3 open source 2D physics engine for use in Flash and Flex.

Based on the open source liba52 library by Aaron Holtzman and Michel Lespinasse

Free/Open Source Multimedia Messaging Service (MMS) gateway.

Gstat is an open source computer code for multivariable geostatistical modelling

an open-source, multi-platform data analysis and visualization application

One of the leading Open Source CMS alternatives available.