Outline

Outline is a fast team wiki and knowledge base with realtime multiplayer editing, threaded comments, and Markdown compatibility. It's built with React, Node.js, and MobX, and explicitly markets millisecond response times, 20+ integrations (Slack, Figma, Loom), and AI-powered "ask your docs" search. Compared to Notion, it's narrower — no databases or block builders — but heavier on speed and search quality.

Outline is not OSI-open source — it uses the Business Source License (BSL). You can self-host, modify, and run Outline for your own organization, but you cannot offer it as a competing hosted/managed service. Each BSL release converts to Apache 2.0 after four years, at which point those versions become fully open. The repo also explicitly rejects AI-generated pull requests.

Outline offers realtime multiplayer document editing with comments, threads, mentions, slash commands, and interactive embeds. Search is instant across the workspace and is paired with an AI question-answering feature that pulls answers from your documents. It supports 20 languages (including RTL), public sharing with branded domains, and read/write permissions with groups and guests.

The official self-hosting docs live at docs.getoutline.com/s/hosting; a production setup typically requires Postgres, Redis, an S3-compatible object store, and the Dockerfile shipped in the repo. Tests are written in Vitest (yarn test:server, yarn test:app), and the architecture document (docs/ARCHITECTURE.md) explains the React + Node.js split. You can also use the hosted version at getoutline.com with a 30-day free trial.