There was a project called ZeroNet where every site you visited, you could also cache and seed via a built-in torrent protocol. But like all good ideas, it was prone to abuse and people started using it to host childcorn, so it was dangerous to even look through the indexes because you might inadvertently start sharing something illegal.

It tried to use NameCoin for .bit addresses as its DNS system, but the whole process was poorly documented.

...and I don't think it ever implemented DHT, so when the trackers for it went down the project kinda died. Plus researchers found a ton of security problems with it in general that were never addressed.

I've been meaning to setup an archive box instance so I could archive stuff myself for my own use. I use LinkDing to self host my own bookmark server.

Oh and I think FreeNet is still in use; an anonymous distributed encrypted web content system.