FreeImage is a library project for developers who would like to support popular graphics image formats (PNG, JPEG, TIFF, BMP and others). Some highlights are: extremely simple in use, not limited to the local PC (unique FreeImageIO) and Plugin driven!
Asymptote is a powerful descriptive vector graphics language for technical drawing, inspired by MetaPost but with an improved C++-like syntax. Asymptote provides for figures the same high-quality level of typesetting that LaTeX does for scientific text.
A Linux, Windows & OSX vector graphics editor (SVG format) featuring transparency, gradients, node editing, pattern fills, PNG export, and more. Aiming for capabilities similar to Illustrator, CorelDraw, Visio, etc.
A very high quality package of printer drivers for Ghostscript and CUPS on Linux, Macintosh OS X, and other POSIX-compliant operating systems. This project also maintains an enhanced Print plug-in for GIMP 2.x from the same code base.
The UFRaw (Unidentified Flying Raw) is a tool for reading and manipulating raw images from digital cameras. It supports most of the existing raw formats (any format supported by DCRaw). UFRaw can be used on its own or as a Gimp plug-in.