Scientific Charting with JavaFX
PHIGS (Programmer's Hierarchical Interactive Graphics System)
The most popular mindmapping and brainstorming software
Run Photo Marathons
Free drawing software for Windows, Mac OS X, and Linux
Multiplatform GUI to losslessly compress JPEG files
A keyboard-friendly image viewer in Gtk2-perl
Real-time interactive fractal zoomer
First index images by contents, then search the index for similarities
Quick gif animation creator