Obsidian

Obsidian is a note-taking and personal knowledge management application that stores everything as plain Markdown files on the user's own device. It links notes together into a navigable web of ideas, and an interactive graph view, backlinks, and a deep library of community plugins let people shape it into a writing studio, research archive, or task system.

It is built for writers, researchers, students, and knowledge workers who want durable, local-first notes they fully control rather than data locked inside a cloud service. Because files stay on disk, notes remain readable even without the app, and power users appreciate its speed, extensibility, and offline reliability.

The core app is free for personal use, with optional paid Sync and Publish add-ons and a commercial licence for business teams. Created by the makers of Dynalist, Obsidian grew largely through word of mouth and has never taken outside venture funding.