The first and original Wiki.
It used to be pretty cool and popular. Then the author wanted to promoted WikiWiki as FederatedSoftware, which was a cool idea, but the implementation kind of sucked. He tried locking WikiWiki to force people to use his new software but nobody did. So the old WikiWiki was brought back, but with cancer JavaScript and bad design choices added as his form of revenge against his users. So now WikiWiki is dead: long live WikiWiki!
To learn what happened next, visit WikiWikiWiki.