owlyph

This is one of the most innovative PKM (and more) tools available. The AnyType team has created an intriguing and appealing foundation (protocol, next gen sync technique, etc.) that works really well across devices and platforms. It provides really functional building blocks to make it a great knowledge management companion but also to share and collaborate with others. It provides excellent link-centric (backlinks, outgoing links, etc.) visibility between the knowledge graph objects and has uniquely useful ways of enabling you to move between those (e.g. its Flow display). They've improved their user interface to make it simpler and more intuitive in the recent versions so it no longer has the somewhat difficult learning curve that it had in its early days.

Exporting data is much better than it was in earlier releases but there are still a few issues that could be improved to ensure that all forms of data are completely exported and portable to other tools. Issues here and there to improve UI/UX quality seem to be getting gradually taken care of. The search works well and there are so many query options that finding notes is not really a problem but it could be improved to also have advanced search functionality.

Very flexible with how you can store, organize, and find notes in an interface that supports markdown but also provides nice additional features. It values linking between objects like Obsidian does but enables many other views through queries (similar to Capacities or Notion). It provides its own, open and very secure technique for synchronizing and sharing data that seems very future-oriented. The developers seem very active in refining and implementing important functionality but also have a very positive philosophy on their approach to the tool and work. It is open and the paid services come at a reasonable cost.