History of wikipedia began with its first edit on 15 January 2001, two days after the domain was registered by Jimmy Wales and Larry Sanger. Its technological and conceptual underpinnings predate this

HISTORY OF WIKIPEDIA Wikipedia began with its first edit on 15 January 2001, two days after the domain was registered by Jimmy Wales and Larry Sanger. Its technological and conceptual underpinnings predate this; the earliest known proposal for an online encyclopedia was made by Rick Gates in 1993, and the concept of a free-as-in-freedom online encyclopedia (as distinct from mere open source) was proposed by Richard Stallman in December 2000.

Crucially, Stallman's concept specifically included the idea that no central organization should control editing. This characteristic greatly contrasted with contemporary digital encyclopedias such as Microsoft Encarta, Encyclopædia Britannica, and even Bomis's Nupedia, which was Wikipedia's direct predecessor. In 2001, the license for Nupedia was changed to GFDL, and Wales and Sanger launched Wikipedia using the concept and technology of a wiki pioneered in 1995 by Ward Cunningham. Initially, Wikipedia was intended to complement Nupedia, an online encyclopedia project edited solely by experts, by providing additional draft articles and ideas for it. In practice, Wikipedia quickly overtook Nupedia, becoming a global project in multiple languages and inspiring a wide range of other online reference projects.

According to Alexa Internet, as of December 2019, Wikipedia is the world's ninth-most-popular website in terms of what it terms global internet engagement. Wikipedia's worldwide monthly readership is approximately 495 million. Worldwide in September 2018, WMF Labs tallied 15.5 billion page views for the month. According to comScore, Wikipedia receives over 117 million monthly unique visitors from the United States alone. The concept of compiling the world's knowledge in a single location dates back to the ancient Libraries of Alexandria and Pergamum, but the modern concept of a general-purpose, widely distributed, printed encyclopedia originated with Denis Diderot and the 18th-century French encyclopedists. The idea of using automated machinery beyond the printing press to build a more useful encyclopedia can be traced to Paul Otlet's 1934 book Traité de documentation; Otlet also founded the Mundaneum, an institution dedicated to indexing the world's knowledge, in 1910.

This concept of a machine-assisted encyclopedia was further expanded in H. G. Wells' book of essays World Brain (1938) and Vannevar Bush's future vision of the microfilm-based Memex in his essay "As We May Think" (1945). Another milestone was Ted Nelson's hypertext design Project Xanadu, which was begun in 1960. Advances in information technology in the late 20th century led to changes in the form of encyclopedias. While previous encyclopedias, notably the Encyclopædia Britannica, were book-based, Microsoft's Encarta, published in 1993, was available on CD-ROM and hyperlinked. The development of the World Wide Web led to many attempts to develop internet encyclopedia projects.

An early proposal for an online encyclopedia was Interpedia in 1993 by Rick Gates; this project died before generating any encyclopedic content. Free software proponent Richard Stallman described the usefulness of a "Free Universal Encyclopedia and Learning Resource" in 1999. His published document "aims to lay out what the free encyclopedia needs to do, what sort of freedoms it needs to give the public, and how we can get started on developing it." On Wednesday 17 January 2001, two days after the founding of Wikipedia, the Free Software Foundation's (FSF) GNUPedia project went online, competing with Nupedia, but today the FSF encourages people "to visit and contribute to [Wikipedia]"