BookStack

BookStack organizes documentation into a hierarchy that actually makes sense: shelves hold books, books hold chapters, chapters hold pages. It is a wiki built for people who think in structure, not chaos. The WYSIWYG editor works out of the box, no markdown gatekeeping required.

Role-based permissions let you lock down who sees what, which matters once your team grows past five people. Multi-factor auth, audit logging, LDAP and SAML support ship built in. Diagrams.net integration, API access, and full-text search round it out. If you have tried Notion or Confluence and wanted something you actually own, this is the answer. GitBook gives you hosted convenience but locks your docs behind their platform. Outline looks slicker but needs more infrastructure to run. Wiki.js is the other serious self-hosted option but feels more generic.

The catch: it is PHP and Laravel, so you need a traditional LAMP-style server. No official hosted version exists. You run it or you do not use it.