SiYuan
Free tierBlock-level bidirectional linking, stored as Markdown files on your disk
An open-source personal knowledge tool with block-level references and bidirectional links, storing notes as Markdown files in a local folder. Run the desktop build standalone, or deploy it with Docker as a server so phones and computers reach the same data over your LAN or your own host.
Why we picked it
AGPL-3.0, 46,200 stars, one of the most widely used bidirectional-linking note tools in the Chinese community.
The division of labour against Obsidian is clean. Obsidian is closed source (free, but not open) with a larger plugin ecosystem; SiYuan is AGPL open source and takes block references further — the unit of reference is a block rather than a file, so a paragraph can be embedded elsewhere and stay in sync. For card-style notes and structured organisation that difference matters.
Data lands in local Markdown files at a path you choose, and can be taken away at any time. No account, and full functionality offline. It also runs as a server under Docker: put an instance on a home NAS and phones and computers reach the same notes over the LAN, with access controlled by an authorisation code — enough for a small team.
Chinese-language handling is a real strength: interface, documentation and community are all natively Chinese, and details like CJK-Latin spacing, punctuation and fonts are handled more carefully than in most tools built elsewhere.
To be clear about:
- Official cloud sync costs money, which is why it is marked freemium. Sync is not locked to that cloud though: you can configure S3 or WebDAV yourself, or simply point Syncthing at the folder, both free. The note-taking core has no feature wall, and the project states most features are free even commercially.
- The interface is dense. There are many features and the first launch looks button-heavy. For a minimal writing environment, Zettlr or Obsidian feel lighter.