FotoFlexer - FotoFlexer is the most powerful online photo editor in existence.
Krita - Krita is a professional FREE and open source painting program. It is made by artists that want to seaffordable art tools for everyone. Concept art. texture and matte painters, illustrations and comics.
Fun Photo Box - FunPhotoBox is a free photo editing device where you can make clever pictures from your photographs.
MyPaint - MyPaint is a fast, distraction-free, and easy painting tool for digital artists.
piZap - Free online photo editing software.
GIMP - GIMP is a multiplatform photo manipulation tool.