Thanks for your advice. Eidos is more like a PDM tool rather than a PKM tool, but it can be used as a PKM with some extensions, just as the introduction says, it's an extensible framework.

I've used the tools you mentioned and more. None of them have a powerful table, which is one of the reasons I decided to create Eidos. Eidos can handle large amounts of data like Excel. Anytype/Outline cannot do this.

I plan to follow Obsidian's model, with the core being always free. here is some plans: - publish service (subscription-based) - peer-to-peer data synchronization (One-time payment, like Resilio sync) - an extension store that benefits developers (still a rough idea in my mind)