The Internet version of the newspaper. A concentration of ideas, editorial, resources, rants and people in a convenient, easy-to-maintain state. People can get the word out easily on this piece of technology.
At least, that's how its supposed to be. Depending on the community you might find a lot of assholes looking to grind axes. If you ignore them for long enough, however, they tend to go away. Does anyone remember the last flamewar, starring some DramaQueen? on ReligionLinks?
After a while the site will grow to a point when no individual can gimp up more than their small corner of it. It isn't a tree structure, so much as a semiotic field, and there should be few, if any, critical links.
A guy named Christopher Alexander created Pattern Languages to contain solutions to an architecture design situations. His PLs were on paper, in a couple of big books. Then a guy named Ward Cunningham created Wiki to contain Pattern Languages on line. (It was Ward's code that was originally running on this site - between 500 and 600 lines of Perl.) Then people started using Wiki for all kinds of things, including the amazing Wikipedia. Links: