Pixelitor - Pixelitor is a cross-platform raster graphics editor written in Java.
RealWorld Paint - RealWorld Paint is an free portable image/photo/animation editor.
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.
JugiPaint - JugiPaint is a painting software with diverse tools for various types of illustration work.
RealWorld Photos - RealWorld Photos is an free portable photo editor for Windows.
Paint +++ - Paint +++ is a native image editor for Mac that enables you to complete everyday image editing tasks in a single place.