Wiki.js

Wiki.js is a powerful, open-source wiki software built for modern documentation. It can be self-hosted, supports Markdown editing, stores content in Git or a database, and includes fine-grained access control and analytics. It's designed for companies and teams needing a professional, self-hosted internal knowledge base. It's free to use (self-hosted).

It ranks as a top-tier self-hosted wiki solution, offering a balance of user-friendliness and powerful administrative features for enterprise deployments.