Gimp

http://www.gimp.org

"GIMP is an acronym for GNU Image Manipulation Program. It is a freely distributed program for such tasks as photo retouching, image composition and image authoring."

The Gimp's main web page is getting redone from groundup, see: http://mmmaybe.gimp.org/

Gimp for windows: http://www2.arnes.si/~sopjsimo/gimp/

CVS supports SVG now

See also LinuxApplications, Windows, SVG