BookStack

BookStack is a documentation and wiki platform that organises content in a deliberately simple hierarchy of books, chapters, and pages, so the structure stays predictable for both writers and readers. It ships with full-text search, page revision history, tags, and permissions that can be applied at the book, chapter, and page level.

Teams use it for internal handbooks, runbooks, and onboarding material, and small groups run public wikis on it.

Running it yourself keeps internal documentation on your own servers, with no per-user licence fees and a database and file storage that are easy to back up and restore.