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.
Vectr - Free vector graphics editor. A simple yet powerful web and desktop cross-platform tool for everyone.
Autodesk SketchBook - SketchBook drawing and painting software provides designers, architects, and concept artists the tools to sketch ideas quickly and create beautiful illustrations.
Vecteezy Editor - Free Online Vector Editor - Design and customize SVG illustrations and graphics quickly and easily in your browser.
Clip Studio Paint - The artist's software for drawing and painting.
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.