Adobe Photoshop - Adobe Photoshop is a webtop application for editing images and photos online.
PaintTool SAI - Learn to draw in different ways.
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.
Corel Painter - Corel Painter is media painting software.
MyPaint - MyPaint is a fast, distraction-free, and easy painting tool for digital artists.
TwistedBrush Pro Studio - A powerful and unique natural media painting program.