GitBook - Modern Publishing, Simply taking your books from ideas to finished, polished books.
Kahoot! - Kahoot! makes it easy to create, play and share fun learning games in minutes—for any subject, in any language, on any device.
MkDocs - Project documentation with Markdown.
Sli.do - Slido is the ultimate Q&A and polling platform for live and virtual meetings and events. It offers interactive Q&A, live polls and insights about your audience.
Docusaurus - Easy to maintain open source documentation websites
Mentimeter - a web-based polling tool for workshops, conferences & events