darktable is an open source photography workflow application
Highly Optimized Graphics Math (glm) for C
A free, high-quality, and portable font engine
Model Railway CAD program
Swiss army knife of image processing
Lynkeos is an astronomical webcam image processing software for OS X.
Display, convert, and edit raster image and vector image files
Cross Platform GUI Toolkit
Scanning Probe Microscopy Controller and Data Visualization Software
Create PDF from JPEG scans and photos
ZuneFIG is the Zunified version of old xfig conversion to amiga
Graphic Live Mixer
Transforms bitmaps into vector graphics
Free yourself
Former project page
Universal graphics translator
Free drawing software for Windows, Mac OS X, and Linux
Not your usual Architectural Modeler