Think: Community Thesaurus.
A web database created by Rob Malda (aka CmdrTaco) and Nate Oostendorp (the slashdot folks) in perl. Everything is a system which allows the slashdot community (or your local ontogroup, the source code is of course free) to name and writeup everything they deem interesting. Everything divides the world into four categories or classes: people, places, things and ideas.
From the FAQ:
... Therefore we came up with the idea of having a communally-maintaine d database - something where joe-average user can vote to insure quality of content.
Profuse linkage is the key to Everything's structure. Links are created any time a person moves from one node to another, and strengthed if travelled again. Sometimes links (such as links in writeups) are required to define a node. The links at the bottom, however, are more likely to be loosely, if at all associated with a node - but they provide paths to new trains of thought.
Everything Theory (a node at Everything): 'The hypothesis that a finite medium can be used to categorize all things.'
Everything (a very big node at Everything)
Version 2 of Everything.