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.
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
Autodesk SketchBook - SketchBook drawing and painting software provides designers, architects, and concept artists the tools to sketch ideas quickly and create beautiful illustrations.
Sculptris - Sculptris: Enter a world of digital art without barriers.
Clip Studio Paint - The artist's software for drawing and painting.
ShapeShop - ShapeShop is an advanced and professional 3D design and modeling application that comes with an easy-to-use and user-friendly interface.