I've been using #logseq for the past year. It's an awesome open-source combination of outliner/block-based notetaking mixed with electron-based feature-rich Zettlekasten's like Obsidian or Foam, and is similarly file based meaning low lock-in risks and easy integration with other tools. It also has a lot of cool features like Datalog integration, pdf & video tools, a nice mobile app, and lots of great opinionated defaults. I've been only using md, but it also supports org formatting.