svg editor: Easily create documents for math, physics, chemistry...
An algebra editor
Qt based Veroboard, Perfboard, and PCB layout and routing application
GPS track editor for editing tracks and planning (multiple) day tours
Editor for Zometool models
Event recorder software for animal and human behaviour research.
Newsfeed aggregator
Free tool designed to make client side hacking easy
Python-based GUI for discrete-event system modeling and simulation