The Wikimedia Foundation (WMF) is an American non-profit and charitable organization headquartered in San Francisco, California, that operates many wikis. The foundation is mostly known for hosting Wikipedia, the Internet encyclopedia, as well as Wiktionary, Wikiquote, Wikibooks, Wikisource, Wikimedia Commons, Wikispecies, Wikinews, Wikiversity, WikiData, Wikivoyage, Wikimedia Incubator, and Meta-Wiki. It also owned the now-defunct Nupedia.