BookStack is a self-hosted platform for organising and storing information as a wiki. Content is arranged in books, chapters and pages, with a WYSIWYG editor and an optional Markdown editor, diagrams.net drawings, full-text search, page revisions and a role-based permission system. Sign-in works with email and password, OIDC, SAML2 or LDAP, and multi-factor authentication can be enforced per role. It is built with PHP, Laravel and MySQL and is installed on the organisation's own server.
BookStack is open source under the MIT licence and was created by Dan Brown. Official support services are provided through HTTP Functions Ltd, a UK limited company, so the commercial side of the project sits in the United Kingdom, outside the EU. The project does not offer managed hosting of its own. Organisations run BookStack on infrastructure of their choice, including servers in the EU, and keep control over where data is stored. The project is funded by donations, sponsorships and support offerings, and says it does not accept investment.