0docs vs Fern

0docs is a free, open-source documentation platform that teams can self-host to create, style, version, and publish documentation. Its MIT-licensed editor arranges content into pages, sections, and blocks such as callouts, steps, code tabs, cards, accordions, and API endpoints. Users can change colors, fonts, sidebar presentation, and individual block styles, then publish documentation snapshots using a custom domain. The “Ask docs” feature answers questions from published documentation and requires an OpenAI API key; an OpenAI-compatible base URL override is documented. AI clients can use a built-in MCP endpoint to read and edit documentation with project tokens or anonymous read-only access. The platform requires PostgreSQL, storing uploaded media there by default or in optional S3-compatible storage. Local installation calls for Node.js 20+ and pnpm, plus Docker Compose or PostgreSQL 14+. The default upload maximum is 20 MB per upload. SMTP is optional, but without it password-reset and invitation links appear in server logs. The self-hosting guide recommends HTTPS, database backups, and production configuration.

Fern has no write-up on Specifiction yet; its figures are above.