Wikipedia [ c ] is a free-content online encyclopedia written and maintained by a community of volunteers , known as Wikipedians , through open collaboration and the wiki software MediaWiki. Wikipedia is the largest and most-read reference work in history, [ 3 ] [ 4 ] and is consistently ranked among the ten most visited websites ; as of December [update] , it was ranked fifth by Semrush , [ 5 ] and seventh by Similarweb.
Initially only available in English, Wikipedia now exists in more than languages. The English Wikipedia , with over 7 million articles, remains the largest of the editions, which together comprise more than 64 million articles and attract more than 1.
Wikipedia has been praised for its enablement of the democratization of knowledge , extent of coverage, unique structure, and culture. Wikipedia has been censored by some national governments, ranging from specific pages to the entire site.
Various collaborative online encyclopedias were attempted before the start of Wikipedia, but with limited success. Wikipedia was launched on January 15, [ 20 ] referred to as Wikipedia Day as a single English-language edition at www.
Otherwise, there were initially relatively few rules, and it operated independently of Nupedia. Wikipedia gained early contributors from Nupedia, Slashdot postings, and web search engine indexing.
