THE GIMP

GIMP is a free Image Manipulation Program. It can be used for photo retouching, image composition and image creating. It is cross platform for Linux desktop users as well as Microsoft Windows and Macintosh. http://www.gimp.org/

Gimpshop is a version of GIMP that more closely mimics the indistry standard Photoshop software. Find it here http://www.gimpshop.com/