Wikipedia is a free, collaboratively edited and multilingual Internet encyclopedia supported by the non-profit Wikimedia Foundation. Its 22 million articles (over 3.9 million in English alone) have been written collaboratively by volunteers around the world. Almost all of its articles can be edited by anyone with access to the site, and it has about 100,000 regularly active contributors. As of May 2012, there are editions of Wikipedia in 285 languages. It has become the largest and most popular general reference work on the Internet, ranking sixth globally among all websites on Alexa and having an estimated 365 million readers worldwide. It is estimated that Wikipedia receives 2.7 billion monthly pageviews from the United States alone.
Wikipedia was launched in January 2001 by Jimmy Wales and Larry Sanger. Sanger coined the name Wikipedia, which is a portmanteau ofwiki (a type of collaborative website, from the Hawaiian word wiki, meaning "quick") and encyclopedia. Wikipedia's departure from the expert-driven style of encyclopedia building and the presence of a large body of unacademic content have received extensive attention in print media. In its 2006Person of the Year article, Time magazine recognized the rapid growth of online collaboration and interaction by millions of people around the world. It cited Wikipedia as an example, in addition to YouTube, MySpace, and Facebook. Wikipedia has also been praised as a news source because of how quickly articles about recent events appear. Students have been assigned to write Wikipedia articles as an exercise in clearly and succinctly explaining difficult concepts to an uninitiated audience.
Although the policies of Wikipedia strongly espouse verifiability and a neutral point of view, criticisms leveled at Wikipedia include allegations about quality of writing, inaccurate or inconsistent information, and explicit content. Various experts (including founder Jimmy Wales and Jonathan Zittrain of Oxford University) have expressed concern over possible (intentional or unintentional) biases. These allegations are variously addressed by Wikipedia policies.
Other disparagers of Wikipedia simply point out vulnerabilities inherent to any wiki that may be edited by anyone. These critics observe that much weight is given to topics that more editors are likely to know about, like popular culture, and that the site is vulnerable to vandalism, though some studies indicate that vandalism is quickly deleted. Critics point out that some articles contain unverified or inconsistent information, though a 2005 investigation in Nature showed that the science articles they compared came close to the level of accuracy of Encyclopædia Britannica and had a similar rate of "serious errors".Wikipedia began as a complementary project for Nupedia, a free online English-language encyclopedia project whose articles were written by experts and reviewed under a formal process. Nupedia was founded on March 9, 2000, under the ownership of Bomis, Inc, a web portal company. Its main figures were Jimmy Wales, Bomis CEO, and Larry Sanger, editor-in-chief for Nupedia and later Wikipedia. Nupedia was licensed initially under its own Nupedia Open Content License, switching to the GNU Free Documentation License before Wikipedia's founding at the urging of Richard Stallman.Larry Sanger and Jimmy Wales founded Wikipedia. While Wales is credited with defining the goal of making a publicly editable encyclopedia, Sanger is usually credited with the strategy of using a wiki to reach that goal. On January 10, 2001, Sanger proposed on the Nupedia mailing list to create a wiki as a "feeder" project for Nupedia. Wikipedia was formally launched on January 15, 2001, as a single English-language edition at www.wikipedia.com, and announced by Sanger on the Nupedia mailing list. Wikipedia's policy of "neutral point-of-view" was codified in its initial months, and was similar to Nupedia's earlier "nonbiased" policy Wikipedia has been a good website and it helps everyone to search what they need to search for