IcoFX - IcoFX is an all-in-one solution for icon creation, extraction and editing.
GIMP - GIMP is a multiplatform photo manipulation tool.
RealWorld Icon Editor - Create Windows icons and Mac OS icons from images and 3D models in an integrated icon maker.
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.
IconLover - Icon editor for Windows.
MyPaint - MyPaint is a fast, distraction-free, and easy painting tool for digital artists.