SiYuan

SiYuan is an open-source personal knowledge management system. It focuses on privacy and local-first data storage, allowing users to organize information using a block-based structure with bidirectional linking. The system is designed to help users refactor their thinking by treating every piece of content as a discrete block that can be referenced across the entire workspace.

The software is available as a desktop application built on Electron and as mobile apps for Android, iOS, and HarmonyOS. For those who prefer server-side control, it can be deployed using Docker. This deployment method allows users to host their own knowledge base on a private server and access it via a web browser, with options to configure access authentication codes and custom user permissions for secure data management.

Key features

• Block-level references and two-way links for granular data connection
• Markdown WYSIWYG editor supporting million-word large documents
• Relational database capabilities with table views
• Spaced repetition system using flashcards for active recall
• AI writing and Q&A integration via OpenAI API
• Support for mathematical formulas, charts, flowcharts, and Gantt charts
• PDF annotation linking and web clipping via browser extensions
• Export options for Markdown, PDF, Word, and HTML

SiYuan utilizes a modular architecture consisting of the Lute editor engine and the Dejavu data repository. It supports high levels of customization through a plugin API and a community marketplace where users can find JavaScript and CSS snippets. The system is built for power users who require a structured wiki-like environment, offering advanced capabilities such as SQL query embeds to retrieve specific data from the internal database.

It serves as a comprehensive tool for individuals seeking a private, local-first system that combines the flexibility of a notebook with the structure of a database.