Wikiunity

Wikiunity is a free wiki hosting service that uses MediaWiki. Unlike some other wiki hosters Wikiunity wants to be close to the users and works with them hand in hand. Wikiunity offers the users are free to create a wiki and use the skin of their choice. Wikiunity is a multiple languages project.

Extensions
Some of Wikiunity's extensions can be found at Wikimedia's official SVN repository and their appropriate extension pages are located at Category:Extensions by Wikiunity.