USBDescriptorKitchen is a GUI-driven tool that helps developers of USB firmwares to ease the pain of calculating lengths of descriptors, fiddling with bits, dealing with variable length fields, etc.
I2C4Java is a simple demonstration of I2C-Java. It uses the Devantech USB-I2C Interface and the Microchip PICkit I2C Demoboard. The software package contains the complete Netbeans project and a compiled Jar file.
The GNU Octave language for numerical computations
A multi-frontends XMPP client.