MediaWiki

A popular Wiki:WikiEngine. Originally developed by and for Wikipedia, but used for a number of other sites.

http://wikipedia.sourceforge.net/

Used by Symbol:SymbolWiki ( http://symbolwiki.org/ ), WikiPedia:WikiPedia, Wikitravel, and other fine wiki.

Some interesting features of MediaWiki:

• UserBan. Users and IP addresses can be banned from editing.
• Separation of DocumentMode from ThreadMode.
• Namespaces..