- DBpedia derives queryable data by scraping Wikipedia pages
- Powerset is an advanced Wikipedia search engine (though I wasn't terribly impressed with my first attempt to use it; a search for "What is the crime rate in the United States?" On Powerset revealed less useful information than searching for "crime rate United States" directly on Wikipedia -W.)
- Wikitruth appears to be a site dedicated to attacking Wikipedia and its founder, Jimbo Wales: "Wikitruth is a website dedicated to the subject of flaws and issues with the Wikipedia, another website run by Jimbo Wales and a massive, insane army of Wikipedians that he controls with his mind rays." It's not clear how serious they are; the site reads like one long ad hominem rant. It does, however, have a cache of pages supposedly deleted from Wikipedia. (Further research needed to determine if those pages were ever actually on Wikipedia.) An article on Al Gore III (son of former VP Al Gore) apparently was, and is no more (Wikipedia:Articles for deletion/Al Gore III).
- 2007-08 See Who's Editing Wikipedia - Diebold, the CIA, a Campaign (see also: Diebold)