Wiki.js is a full-featured, open-source wiki platform designed for collaborative content management. It provides a rich editing experience with Markdown, AsciiDoc, and a visual editor (ProseMirror), supporting real-time collaborative editing via Yjs and WebSocket. The system is built as a monolith with a Fastify backend, Vue 3 frontend, and PostgreSQL database, with worker threads for background tasks like notifications and webhook delivery. It features a modular architecture with pluggable storage backends (disk, S3, Azure, GCS, Git), authentication strategies (local, OIDC, SAML, LDAP, WebAuthn), analytics providers, and comment systems. The block system allows custom content components (diagrams, maps, PDFs, etc.) as LitElement custom elements. Multi-site and multi-locale support, SCIM provisioning, audit logging, rate limiting, and a scheduler for periodic tasks round out the platform. The codebase is well-structured with extensive comments, but relies on a global `WIKI` object and has complex permission logic that spans multiple layers.