GitBook - Modern Publishing, Simply taking your books from ideas to finished, polished books.
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.
MkDocs - Project documentation with Markdown.
Autodesk SketchBook - SketchBook drawing and painting software provides designers, architects, and concept artists the tools to sketch ideas quickly and create beautiful illustrations.
Docusaurus - Easy to maintain open source documentation websites
Clip Studio Paint - The artist's software for drawing and painting.