The Memento extension allows one to browse an entire MediaWiki site as if it were a date in the past; to do this it adds support for datetime negotiation as specified by the Memento protocol to a MediaWiki system. It provides server-side support to allow a Memento client to navigate a MediaWiki system as it was at a time in the past chosen by a user. To gain an understanding about the functionality provided by Memento's time travel, check out this brief overview that includes temporal navigations across Wikipedia and other web sites