Swiss army knife of image processing
GraphicsMagick provides a set of commandline tools and programming APIs for manipulating, editing, and converting raster and vector images. It is derived from ImageMagick, with the objective of providing better stability and performance than ImageMagick while retaining the original MIT/X11 license.
A whole bunch of utilities for primitive manipulation of graphic images. Wide array of converters from one graphics format to another. E.g. from g3 fax format to jpeg. Many basic graphics editing tools such as magnifying and cropping.
Drawing editors for PostScript, TeX, and web graphics. An embeddable and extendable vector graphic shell.
XDraft is a mechanical drawing editor similar to XFig or various Windoze cad programs, but geared towards more precise drawing. XDraft adds input constraints and other features that makes it highly suitable for power users. Also includes dimensioning.
2d/3d map viewer clients and vehicle simulation server.