Federated wiki (concept)
A federated wiki is one that is in which users help to host the content of the wiki themselves. They can either mirror the entire site or some portion of the pages they find relevant or choose to fork part of it and accept or reject certain edits that they find more or less constructive.
In 2012, Ward Cunningham decided to introduce the Smallest Federated Wiki on Github to allow users to help federate Ward's Wiki or any other projects. (see here). This is similar to InterWiki and MeatBallWiki's idea of OneBigWiki.
Since February 2015 a sample implementation is online: http://c2.fed.wiki.org/