I built a website called “reversible.org” approx. 20 years ago that basically listed on every page the pages that linked to it, as a sort of self-organizing dir

I built a website called “reversible.org” approx. 20 years ago that basically listed on every page the pages that linked to it, as a sort of self-organizing directory. If you were a blog about frogs, you would link to reversible.org/blogs/frofs and there was a list of everyone who categorized themselves as such. Of course, it was spammed to hell and back. I was so dejected about the failure I went off and designed tags on delicious without hierarchy.