All you need is links

Quoting Tim Berners-Lee:

One of the beautiful things about physics is its ongoing quest to find simple rules that describe the behavior of very small, simple objects. Once found, these rules can often be scaled up to describe the behavior of monumental systems in the real world. […]

If the rules governing hypertext links between servers and browsers stayed simple, then our web of a few documents could grow to a global web. The art was to define the few basic, common rules of “protocol” that would allow one computer to talk to another, in such a way that when all computers everywhere did it, the system would thrive, not break down.

Turns out tags, folders, comments, stars, hearts, upvotes, downvotes, outliners, even semantic triplets, they’re all just links.