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.
Talent Pool by Minty - Reach award-winning illustrators for your projects
Autodesk SketchBook - SketchBook drawing and painting software provides designers, architects, and concept artists the tools to sketch ideas quickly and create beautiful illustrations.
VPaint - Experimental vector graphics editor.
Clip Studio Paint - The artist's software for drawing and painting.
Pixelmator - Pixelmator is an image-editing application for Mac and iPad.