Founded by Jimmy Wales and Larry Sanger on January 15, 2001, Wikipedia is hosted by the Wikimedia Foundation, an American nonprofit organization that employs a staff of over 700 people. Initially only available in English, editions in other languages have been developed.

Based in San Francisco, the Wikimedia Foundation (WMF) is the organization that owns the domain wikipedia.org . The Foundation raises money, distributes grants, controls the servers, develops and deploys software, and does outreach to support Wikimedia projects, including the English Wikipedia.

Wikipedia is a free, open content online encyclopedia created through the collaborative effort of a community of users known as Wikipedians. Anyone registered on the site can create an article for publication; registration is not required to edit articles.

Wikipedia is not a reliable source for citations elsewhere on Wikipedia. As a user-generated source, it can be edited by anyone at any time, and any information it contains at a particular time could be vandalism, a work in progress, or simply incorrect.