Wiki

A wiki is a website that anyone can edit. For more information, see the article about wikis on Wikipedia, the wiki-based free encyclopedia.

Wikis with Doom content:
 * This project, the Doom Wiki (http://doom.wikicities.com)
 * The ZDoom documentation project (http://zdoom.org/wiki/)

Wikipedia also has a fair amount of Doom coverage; see http://en.wikipedia.org/wiki/Category:Doom