The Wikimedia Foundation was incorporated in St. Petersburg, Florida, on June 20, 2003. A small fundraising campaign to keep the servers running was run in October 2003. In 2005, the foundation was granted section 501(c)(3) status by the U.S. Internal Revenue Code as a public charity, making donations to the foundation tax-deductible for U.S. federal income tax purposes. Its National Taxonomy of Exempt Entities (NTEE) code is B60 (Adult, Continuing education).
On December 11, 2006, the foundation's board noted that it could not become a membership organization, as initially planned but not implemented, due to an inability to meet the registration requirements of Florida statutory law. The bylaws were accordingly amended to remove all references to membership rights and activities.
In 2007, the foundation decided to move its headquarters from Florida to the San Francisco Bay Area. Considerations cited for choosing San Francisco were proximity to like-minded organizations and potential partners, a better talent pool, as well as cheaper and more convenient international travel. The move was completed by January 31, 2008, into a headquarters on Stillman Street in San Francisco. It later moved to New Montgomery Street, and then in 2017 to One Montgomery Tower.
On October 25, 2021, the foundation launched Wikimedia Enterprise, a commercial Wikimedia content delivery service aimed at groups that want to use high-volume APIs, starting with Big Tech enterprises. In June 2022, Google and the Internet Archive were announced as the service's first customers, though only Google will pay for the service. The same announcement noted a shifting focus towards smaller companies with similar data needs, supporting the service through "a lot paying a little".
The foundation operates 12 wiki-based content projects that are written and governed by volunteer editors. They include, by launch date:
Wiktionary – online dictionary and thesaurus
Wikibooks – a collection of books, mostly textbooks
Wikiquote – a collection of quotations
Wikimedia Commons – repository of images, sounds, videos, and general media
Wikispecies – taxonomic catalog of species
Wikinews – online newspaper; closed in 2026
Wikiversity – a collection of tutorials and courses and a hosting point to coordinate research