Gimp
The GIMP is a multiplatform photo manipulation tool. GIMP is an acronym for GNU Image Manipulation Program. The GIMP is suitable for a variety of image manipulation tasks, including photo retouching, image composition, and image construction.
Hugin
Hugin Manual (for making panoramas)
Qtpfsgui
krita
digikam
apophysis
apophysis (fhttp://osp.wikidot.com/manualsractal flame editor)
Inkscapes
mathmap
mathmap is a plugin for Gimp, which will allow you, among other things, to create the Escher and Droste effect, famous for its illusion, making an impossible World look real, as the mind has difficulty in discovering the incoherences of the picture. To get more details about it look in: Escher and Droste Effect
The MathMap Language Reference Manual
mathmap for windows Installing mathmap in Windows
A logarithmic image transformation An image transformation method, first used by the artist M.C. Escher, and described by Lenstra et al. is generalized for use in a graphics program.
