How is this different from Zettelkasten? https://en.wikipedia.org/wiki/Zettelkasten

I'd say that this product (https://kinopio.club/) is an implementation of the ideas of Zettelkasten[0], or at least shares a lot of DNA. However, lots and lots of things "are" Zettelkasten, or can work like Zettelkasten, or incorporate ideas of Zettelkasten. Examples of things which can be used like a Zettelkasten include:

- Org mode for Emacs https://en.wikipedia.org/wiki/Org-mode

- Vimwiki for Vim https://github.com/vimwiki/vimwiki

- Notational Velocity, an OS X note-taking application https://en.wikipedia.org/wiki/Notational_Velocity

- Obsidian, a cross platform personal knowledgebase where its "DB format" is folders full of Markdown files https://obsidian.md/

- A folder full of text files which you open in your favorite text editor can even work like a Zettelkasten (grep helps in this case though)

[0] - https://en.wikipedia.org/wiki/Zettelkasten