Wikipedia 
Wikipedia is a free-content online encyclopedia written and maintained by a community of volunteers, collectively known as Wikipedians, through open collaboration and using a wiki-based editing system called MediaWiki. Wikipedia is the largest and most-read reference work in history, and has consistently been one of the 10 most popular websites. Created by Jimmy Wales and Larry Sanger on January 15, 2001, it is hosted by the Wikimedia Foundation, an American nonprofit organization.
Initially available only in English, versions in other languages were quickly developed. Wikipedia's combined editions comprise more than 61 million articles, attracting around 2 billion unique device visits per month and more than 15 million edits per month (about 5.8 edits per second on average) as of July 2023.
Wikipedia has been praised for its enablement of the democratization of knowledge, extent of coverage, unique structure, and culture. It has been criticized for exhibiting systemic bias, particularly gender bias against women and geographical bias against the Global South. While the reliability of Wikipedia was frequently criticized in the 2000s, it has improved over time, receiving greater praise in the late 2010s and early 2020s, having become an important fact-checking site. It has been censored by world governments, ranging from specific pages to the entire site. Articles on breaking news are often accessed as a source of frequently updated information about those events.
History
Nupedia
Various collaborative online encyclopedias were attempted before the start of Wikipedia, but with limited success. 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. It was founded on March 9, 2000, under the ownership of Bomis, a web portal company. Its main figures were Bomis CEO Jimmy Wales and Larry Sanger, editor-in-chief for Nupedia and later Wikipedia. Nupedia was initially licensed under its own Nupedia Open Content License, but before Wikipedia was founded, Nupedia switched to the GNU Free Documentation License at the urging of Richard Stallman. Wales is credited with defining the goal of making a publicly editable encyclopedia, while Sanger is 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.Launch and Growth
The domains wikipedia.com (later redirecting to wikipedia.org) and wikipedia.org were registered on January 12, 2001, and January 13, 2001, respectively. Wikipedia was launched on January 15, 2001 as a single English-language edition at www.wikipedia.com, and announced by Sanger on the Nupedia mailing list. The name originated from a blend of the words wiki and encyclopedia. Its integral policy of "neutral point-of-view" was codified in its first few months. Otherwise, there were initially relatively few rules, and it operated independently of Nupedia. Bomis originally intended it as a business for profit.Wikipedia gained early contributors from Nupedia, Slashdot postings, and web search engine indexing. Language editions were created beginning in March 2001, with a total of 161 in use by the end of 2004. Nupedia and Wikipedia coexisted until the former's servers were taken down permanently in 2003, and its text was incorporated into Wikipedia. The English Wikipedia passed the mark of two million articles on September 9, 2007, making it the largest encyclopedia ever assembled, surpassing the Yongle Encyclopedia made during the Ming dynasty in 1408, which had held the record for almost 600 years.
Citing fears of commercial advertising and lack of control, users of the Spanish Wikipedia forked from Wikipedia to create Enciclopedia Libre in February 2002. Wales then announced that Wikipedia would not display advertisements, and changed Wikipedia's domain from wikipedia.com to wikipedia.org.
Though the English Wikipedia reached three million articles in August 2009, the growth of the edition, in terms of the numbers of new articles and of editors, appears to have peaked around early 2007. Around 1,800 articles were added daily to the encyclopedia in 2006; by 2013 that average was roughly 800. A team at the Palo Alto Research Center attributed this slowing of growth to the project's increasing exclusivity and resistance to change. Others suggest that the growth is flattening naturally because articles that could be called "low-hanging fruit"—topics that clearly merit an article—have already been created and built up extensively.
In November 2009, a researcher at the Rey Juan Carlos University in Madrid, Spain found that the English Wikipedia had lost 49,000 editors during the first three months of 2009; in comparison, it lost only 4,900 editors during the same period in 2008. The Wall Street Journal cited the array of rules applied to editing and disputes related to such content among the reasons for this trend. Wales disputed these claims in 2009, denying the decline and questioning the study's methodology. Two years later, in 2011, he acknowledged a slight decline, noting a decrease from "a little more than 36,000 writers" in June 2010 to 35,800 in June 2011. In the same interview, he also claimed the number of editors was "stable and sustainable". A 2013 MIT Technology Review article, "The Decline of Wikipedia", questioned this claim, revealing that since 2007, Wikipedia had lost a third of its volunteer editors, and that those remaining had focused increasingly on minutiae. In July 2012, The Atlantic reported that the number of administrators was also in decline. In the November 25, 2013, issue of New York magazine, Katherine Ward stated, "Wikipedia, the sixth-most-used website, is facing an internal crisis."
The number of active English Wikipedia editors has since remained steady after a long period of decline.
Milestones
In January 2007, Wikipedia first became one of the ten most popular websites in the United States, according to Comscore Networks. With 42.9 million unique visitors, it was ranked #9, surpassing The New York Times (#10) and Apple (#11). This marked a significant increase over January 2006, when Wikipedia ranked 33rd, with around 18.3 million unique visitors. In 2014, it received eight billion page views every month. On February 9, 2014, The New York Times reported that Wikipedia had 18 billion page views and nearly 500 million unique visitors a month, "according to the ratings firm comScore". As of March 2023, it ranked 6th in popularity, according to Similarweb. Loveland and Reagle argue that, in process, Wikipedia follows a long tradition of historical encyclopedias that have accumulated improvements piecemeal through "stigmergic accumulation".On January 18, 2012, the English Wikipedia participated in a series of coordinated protests against two proposed laws in the United States Congress—the Stop Online Piracy Act (SOPA) and the PROTECT IP Act (PIPA)—by blacking out its pages for 24 hours. More than 162 million people viewed the blackout explanation page that temporarily replaced its content.
In January 2013, 274301 Wikipedia, an asteroid, was named after Wikipedia; in October 2014, Wikipedia was honored with the Wikipedia Monument; and, in July 2015, 106 of the 7,473 700-page volumes of Wikipedia became available as Print Wikipedia. In April 2019, an Israeli lunar lander, Beresheet, crash landed on the surface of the Moon carrying a copy of nearly all of the English Wikipedia engraved on thin nickel plates; experts say the plates likely survived the crash. In June 2019, scientists reported that all 16 GB of article text from the English Wikipedia had been encoded into synthetic DNA.
On January 20, 2014, Subodh Varma reporting for The Economic Times indicated that not only had Wikipedia's growth stalled, it "had lost nearly ten percent of its page views last year. There was a decline of about two billion between December 2012 and December 2013. Its most popular versions are leading the slide: page-views of the English Wikipedia declined by twelve percent, those of German version slid by 17 percent and the Japanese version lost nine percent." Varma added, "While Wikipedia's managers think that this could be due to errors in counting, other experts feel that Google's Knowledge Graphs project launched last year may be gobbling up Wikipedia users." When contacted on this matter, Clay Shirky, associate professor at New York University and fellow at Harvard's Berkman Klein Center for Internet & Society said that he suspected much of the page-view decline was due to Knowledge Graphs, stating, "If you can get your question answered from the search page, you don't need to click [any further]." By the end of December 2016, Wikipedia was ranked the fifth most popular website globally.
As of January 2023, 55,791 English Wikipedia articles have been cited 92,300 times in scholarly journals, from which cloud computing was the most cited page.
On January 18, 2023, Wikipedia debuted a new website redesign, called "Vector 2022". It featured a redesigned menu bar, moving the table of contents to the left as a sidebar, and numerous changes in the locations of buttons like the language selection tool. The update initially received backlash, most notably when editors of the Swahili Wikipedia unanimously voted to revert the changes.