HedgeDoc

HedgeDoc is an open-source, web-based, self-hosted collaborative markdown editor — the successor to the older CodiMD project, which was renamed in 2020 to avoid confusion with another tool. Unlike Notion's block-based editor, HedgeDoc works with raw Markdown you can paste into any other tool, with live preview and syntax highlighting. It also includes a presentation mode powered by reveal.js for turning notes into slides.

Multiple users can edit the same document simultaneously in the browser, with changes synced as they type — only a note link needs to be shared to invite collaborators. A per-note permission dropdown controls whether viewers can edit, have read-only access, or need to log in. Every note also keeps a full revision history, so any past version can be restored with one click.

HedgeDoc has low system requirements and runs smoothly on a Raspberry Pi according to the project. The team provides both a ready-to-use bundle and a Docker image, with an install guide walking through setup. The source is AGPL-3.0-licensed TypeScript, and the project is currently working on a complete rewrite — HedgeDoc 2 — with an alpha available at hedgedoc.dev.

Yes — HedgeDoc supports graph and diagram embeds (Mermaid and similar), mathematical formulas, and embedded media alongside plain Markdown. The presentation mode uses reveal.js to render a HedgeDoc document as a slide deck directly in the browser. These features make it more flexible than a basic text editor while staying focused on a single-document-per-note model.