Segue
Segue supports many of the basic wiki features including content versioning and wiki linking.
Segue is a good application to use small wikis or wikis whose content would benefit from being organized into sections and pages. As well, Segue is good when you want to restrict collaborative editing to a particular group of users. In a given Segue site it is possible to allows other users to edit only portions of the site.
Note: Segue will be phased out over the next year or so. That said, we will be offering migration tools to help move sites created in Segue to other platforms. For more information, see: Segue from Segue