We were also trying to keep track of all the programs, so we'd have a directory of directories, each in OPML. I had software that browsed these networks of OPML directories.
I eventually stopped trying to make this work, but all my tools still do it. In fact in OPML 2.0, the protocol for inclusion was streamlined, to follow the practice that had developed.
This is a big honking idea. If this were to actually happen, it would be an incredible complement to Wikipedia. It probably would help search companies build new engines that give us not just answers, but context. And choice of context. Unlike Wikipedia there could be many ways to arrive at a spot. That would be subject to editorial judgement, and would not require consensus. I think that's a huge deal, and would increase participation. But I'd love to do it mostly cause it would be huge fun.
June 2000: The first blog post here about the World Outline.
June 2002: The Googlish Way to do Directories.
Not sure of the date: Editing the SoapWare directory with Radio's outliner.
A Google search for "world outline" on scripting.com in chronologic order starting in 2000.