Padlet - Visual boards for organizing anything.
Doxygen - Generate documentation from source code
Pinterest - Pinterest is a visual discovery tool that you can use to find ideas for all your projects and interests.
Docsify.js - A magical documentation site generator.
Pearltrees - Pearltrees is a place to organize all your interests. It lets you organize, explore and share everything you like.
GitBook - Modern Publishing, Simply taking your books from ideas to finished, polished books.