MediaWiki is wiki software. MediaWiki powers the http://wikipedia.org website -- the biggest free knowledge base on earth.
Wikis are used by companies and organizations everywhere to create, collaborate and publish information. MediaWiki is the most popular wiki software, and is used by organizations like the [http://wikis.ala.org/readwriteconnect/index.php/ALA_wikis American Library Association]. If you would like assistance in a wiki project, please [http://freephileequality-tech.com/cms/contact contact Newburyport GNUsGreg Rundlett @ eQuality Technology]
There is a complete [[MediaWiki/Presentation|Presentation]] on MediaWiki which includes information on [[MediaWiki/Theming#Nice_Examples|wiki theming]] and also points to many examples -- particularly those that provide a custom look to their wiki.