MyPaint - MyPaint is a fast, distraction-free, and easy painting tool for digital artists.
GIMP - GIMP is a multiplatform photo manipulation tool.
Microsoft Paint - Paint (formerly Paintbrush) is a simple, ultra-basic graphics painting program that is included...
Corel Painter - Corel Painter is media painting software.
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.
KolourPaint - KolourPaint is a free, easy-to-use paint program for KDE (a desktop environment for UNIX).