A self-linking web site
The special feature of this platform was that you didn't need to put links into your text. If the text mentioned the name of another page on the site, it automatically pulled it out as a link, listed to one side of the text. The idea being that the density of the links would make it easy enough to get round the website that there was no need for a hierarchy beyond the home page. This was the same philosophy used by Ward Cunningham's original wiki, where to make it as easy as possible to link pages, all camel-cased "WikiWords" automatically became links.
Another feature inspired by Ward's Wiki which has unfortunately been mainly forgotten in modern wikis was that all links were two-directional.
I still have some sympathy for the approach of listing links to one side of the text, rather than within the body. I's a little odd to interrupt a sentence with a link. If the reader is engaged, they won't want to follow the link, and if they're not, why bury your alternative page suggestion in the middle of the copy?
At the time, the BBC news website shared this viewpoint, but nowadays they have caved in and there are links everywhere.
The density of links didn't make the site easy to navigate. It was fine for a collection of miscellaneous stuff, like a personal website, but if you had actually been trying to find something it would have been quite annoying. In fact I was solving the wrong person's problem. Sure, the writer having to create links is a hurdle, but solving it exacerbates the problem the reader has, to discern why one page is linked to another, and to decide whether that makes it an interesting direction to go in.