Welcome to Wikipedia, the free encyclopedia that anyone can edit.

Wikipedia was founded as an offshoot of Nupedia, a now-abandoned project to produce a free encyclopedia. Nupedia had an elaborate system of peer review and required highly qualified contributors, but the writing of articles was seen as very slow. During 2000, Jimmy Wales, founder of Nupedia, and Larry Sanger, whom Wales had employed to work on the project, discussed various ways to supplement Nupedia with a more open, complementary project.

On the evening of January 2, 2001, Sanger had a conversation over dinner with Ben Kovitz, a computer programmer, in San Diego, California. Kovitz, who was a regular on "Ward's Wiki" (the WikiWikiWeb), explained the wiki concept to Sanger. Sanger saw that a wiki would be an excellent format whereby a more open, less formal encyclopedia project could be pursued. Sanger easily persuaded Wales, who had been introduced to the wiki concept previously, to set up a wiki for Nupedia, and Nupedia's first wiki went online on January 10.

There was considerable resistance on the part of Nupedia's editors and reviewers to the idea of associating Nupedia with a website in the wiki format, however, so the new project was given the name "Wikipedia" and launched on its own domain, wikipedia.com, on January 15 (now humorously called "Wikipedia Day" by some users). The bandwidth and server (located in San Diego) were donated by Wales. Other current and past Bomis employees who have done some work on the encyclopedia include Tim Shell, one of the co-founders of Bomis and its current CEO, and programmer Jason Richey.

In May 2001, the first wave of non-English Wikipedias were launched (in Catalan, Chinese, Dutch, German, Esperanto, French, Hebrew, Italian, Japanese, Portuguese, Russian, Spanish, and Swedish, soon joined by Arabic and Hungarian ). In September, a further commitment to the multilingual provision of Wikipedia was made. At the end of the year, when international statistics first began to be logged, Afrikaans, Norwegian, and Serbocroatian versions were announced.

Begun in 2001, Wikipedia has rapidly grown into the largest reference website on the Internet. The content of Wikipedia is free, written collaboratively by people from all around the world. This website is a wiki, which means that anyone with access to an Internet-connected computer can edit, correct, or improve information throughout the encyclopedia, simply by clicking the edit this page link (with a few minor exceptions, such as protected articles and the main page).

Wikipedia is a registered trademark of the non-profit Wikimedia Foundation, which has created an entire family of wiki projects. On Wikipedia, and its sister projects, you are welcome to be bold and edit articles yourself, contributing knowledge as you see fit in a collaborative way.

In every article, links will guide you to associated articles, often with additional information. You are welcome to add further information, cross-references, or citations, so long as you do so within Wikipedia's editing policies and to an appropriate standard. You do not need to fear accidentally damaging Wikipedia when you add or improve information, as other Wikipedians are always around to advise or correct obvious errors if needed, and the Wikipedia encyclopedia software, known as MediaWiki, is carefully designed to allow easy reversal of editorial mistakes.

Because Wikipedia is an ongoing work to which in principle anybody can contribute, it differs from a paper-based reference source in some very important ways. In particular, older articles tend to be more comprehensive and balanced, while newer articles may still contain significant misinformation, unencyclopedic content, or vandalism. Users need to be aware of this in order to obtain valid information and avoid misinformation which has been recently added and not yet removed.