Various collaborative online encyclopedias were attempted before the start of Wikipedia, but with limited success. Wikipedia founders Jimmy Wales (left) and Larry Sanger (right) Articles on breaking news are often accessed as sources of frequently updated information about those events. It has been censored by some national governments, ranging from specific pages to the entire site. 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 criticized for exhibiting systemic bias, particularly gender bias against women and geographical bias against the Global South. Wikipedia has been praised for its enablement of the democratization of knowledge, extent of coverage, unique structure, and culture. Wikipedia's editions when combined, 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. Initially only available in English, editions in other languages were quickly developed.

Founded by Jimmy Wales and Larry Sanger on January 15, 2001, it is hosted by the Wikimedia Foundation, an American nonprofit organization. Wikipedia is the largest and most-read reference work in history, and has consistently been one of the 10 most popular websites. 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. Most text is also dual-licensed under GFDL media licensing varies

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