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