Free Screenshot Tool
3D Procedural Modelling and Procedural Texturing Tool in OpenGL/C++
Professional quality open source illustration software
A powerful C++ class library for image manipulation
pgf/TikZ diagram editor
ANSI Text Editor like PabloDraw for Windows
Removes the background from images
Business graphics diagramming application + customizable shape lib.
GUI for manipulating djvu files
FNT Font editor
Professional vector flow chart drawing software
A simple, but still feature-rich, graphic editor