Wikipedia is a multilingual, web-based, free-content encyclopedia project based on an openly editable model. The name “Wikipedia” is a portmanteau of the words wiki (a technology for creating collaborative websites, from the Hawaiian word wiki, meaning “quick”) and encyclopedia. Wikipedia’s articles provide links to guide the user to related pages with additional information.
Wikipedia is written collaboratively by largely anonymous Internet volunteers who write without pay. Anyone with Internet access can write and make changes to Wikipedia articles (except in certain cases where editing is restricted to prevent disruption or vandalism). Users can contribute anonymously, under a pseudonym, or with their real identity, if they choose.
The fundamental principles by which Wikipedia operates are the Five pillars. The Wikipedia community has developed many policies and guidelines to improve the encyclopedia; however, it is not a formal requirement to be familiar with them before contributing.
Since its creation in 2001, Wikipedia has grown rapidly into one of the largest reference websites, attracting 400 million unique visitors monthly as of March 2011 according to ComScore. There are more than 91,000 active contributors working on more than 17,000,000 articles in more than 270 languages. As of today, there are 3,647,139 articles in English. Every day, hundreds of thousands of visitors from around the world collectively make tens of thousands of edits and create thousands of new articles to augment the knowledge held by the Wikipedia encyclopedia.
Wikipedia history
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 slow. During 2000, Jimmy Wales, founder of Nupedia, and Larry Sanger, whom Wales had employed to work on the project, discussed ways of supplementing Nupedia with a more open, complementary project. Multiple sources suggested the idea that a wiki might allow members of the public to contribute material, and Nupedia’s first wiki went online on January 10, 2001.
Information Courtesy : Wikipedia