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.
ChemDraw - ChemDraw - The Gold Standard for Chemical Structure Drawing and Research Publications.
Artrage - A simple but lovely natural media painting and sketching program.
Avogadro - Avogadro is a free, fantastically easy to use molecule editor.
PaintTool SAI - Learn to draw in different ways.
Gnome Chemistry Utils - The Gnome Chemistry Utils include six chemistry related programs: