HedgeDoc (formerly known as CodiMD) is an open-source, web-based, self-hosted, collaborative markdown editor.
You can use it to easily collaborate on notes, graphs and even presentations in real-time. All you need to do is to share your note-link to your co-workers and they’re ready to go.
Foam is a personal knowledge management and sharing system inspired by Roam Research, built on Visual Studio Code and GitHub.
You can use Foam for organising your research, keeping re-discoverable notes, writing long-form content and, optionally, publishing it to the web.
Foam is free, open source, and extremely extensible to suit your personal workflow. You own the information you create with Foam, and you’re free to share it, and collaborate on it with anyone you want.
MkDocs is a fast, simple and downright gorgeous static site generator that's geared towards building project documentation. Documentation source files are written in Markdown, and configured with a single YAML configuration file.