SiYuan

SiYuan is a privacy-focused, open-source personal knowledge management application that organizes content as editable blocks and supports Markdown WYSIWYG. It emphasizes local-first storage with optional end-to-end encrypted synchronization and offers desktop, mobile and Docker deployments.

Key Features

• Block-based editor with block-level references and two-way links for fine-grained connections.
• Markdown WYSIWYG editing plus large-document (million-word) editing with dynamic loading.
• Built-in database/table view, SQL query embeds and template/snippet support.
• Spaced-repetition flashcards and AI-assisted writing/Q&A via external model APIs.
• OCR support (Tesseract), PDF annotation linking and rich embeds (charts, flowcharts, math).
• Multiple sync options including end-to-end encrypted sync, S3 and WebDAV backends, and Docker deployment.

Use Cases

• Personal knowledge management and research notes with block-level linking for networked thought.
• Publishing and documentation workflows where notes are exported to standard Markdown, HTML or platform-targeted formats.
• Shared team knowledge bases or a self-hosted notes server accessible via Docker and mobile/desktop clients.

Limitations and Considerations

• Some member-only features require payment; the project notes that some capabilities are gated for paid members.
• Community discussions and repository issues have raised concerns about telemetry defaults and the need for careful plugin vetting; administrators should review telemetry and plugin settings for privacy-sensitive deployments.

SiYuan combines a block-first editor model with server-backed features (Docker, APIs, sync) and desktop/mobile clients, making it suitable for users who want a privacy-oriented, extensible PKM system. Its active open-source repository and plugin ecosystem support customization, but administrators should review paid-feature gating and telemetry settings before production use.