Obsidian

Obsidian provides its core note-taking and knowledge-management application free for personal, commercial and non-profit use. Users can create local vaults of Markdown notes, link ideas together, use plugins and customize their workspace without creating an account or purchasing a commercial-use license.

The core application is local-first rather than a hosted collaboration workspace. Official device synchronization and publishing are optional paid services, although users can manage their own file-sync workflows. Team collaboration and managed sharing are therefore less straightforward than in cloud-first products.

Individuals, researchers, writers and professionals who want local Markdown notes, linked knowledge and a customizable personal knowledge base.