GIMP - GIMP is a multiplatform photo manipulation tool.
KiddoPaint - MS Paint in your browser (with emojis 💃😽🎨)
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.
GIF Paint - Like MSPaint… for GIFs.
MyPaint - MyPaint is a fast, distraction-free, and easy painting tool for digital artists.
JS Paint - JSPaint is a web-based Microsoft Paint remake