Wikipedia changed publishing by putting the power to write, edit, update and govern information in the hands of the public. It has become one of the most popular and relied-on resources around the world, with a crowdsource format that allows anyone with a computer to contribute. The website is written in hundreds of languages and has generated nearly 6 million articles in English alone.

Information covered in Wikipedia ranges from conventional biographies and historical events to oddity articles on the dancing plague of 1518, a list of animals with fraudulent diplomas and helicopter prison escapes.

HistoryWikipedia co-founder Jimmy Wales’ first attempt at an online encyclopedia was Nupedia in 2000. But the site had several problems, including a cumbersome review process: Only 21 articles were approved by the end of the first year, and the site disbanded soon after.

Larry Sanger, who had served as Nupedia’s editor-in-chief, was introduced to a new, user-friendly concept called a “wiki” that allowed groups of users to create content collaboratively. Tapping into the tech, the two launched wikipedia.com as a project on 15 January 2001. The site eventually changed to wikipedia.org to reflect its nonprofit status.

GrowthBy the end of the site’s first full month, 617 entries existed on Wikipedia, jumping to 20,000 entries by the end of 2001. German became the first non-English-language site that same year, with other languages quickly following, including Catalan, Japanese and French.

Today, Wikipedia is written in more than 300 languages. Scores of contributors create nearly 600 new articles per day, with an edit happening roughly every 1.8 seconds. Of the top five most-visited websites in the world, Wikipedia is the only one that isn’t profit-driven.

“Imagine a world in which every single person on the planet is given free access to the sum of all human knowledge. That’s what we’re doing.”

Jimmy Wales

Wikipedia co-founder

GovernanceFrom the beginning, Wales established a neutral point of view as one of the site’s “nonnegotiable” policies. Material also has to be verifiable, with information coming from a reliable source. While anyone can contribute, the self-governing structure means Wikipedia users monitor every change and can delete anything inaccurate or inappropriate.

However, errors on the site are still fairly common (and sometimes intentional). To increase reliability, Wikipedia pages have annotations linking to sources and explicitly note articles that don’t have enough citations to be credible. Wikipedia also credits resolving such inaccuracies to the growth of its millions of users, including more than 36 million accounts that have registered to edit an article in English.

ControversyWikipedia has faced criticism for what is not on the site. In particular, it has been called out for a lack of content about and written by women, minorities and underrepresented groups less likely to have access to the internet. Approximately 16 percent of the site’s volunteer editors identify as female, according to an analysis published by the National Center for Biotechnology Information. Europe and North America account for 84 percent of articles about specific geographic places or events, according to researchers at the Oxford Internet Institute.

To counter the issue, Wikipedia has turned to the regulating powers of its contributors to identify and fill the content and point-of-view gaps. It’s an important step for a site that aims, according to Wales, to represent the “sum of all human knowledge.”

ExpansionWikipedia has launched sister projects that have spilled into other facets of media and information. All of them are wikis and run by the Wikimedia Foundation. These projects include the online dictionary Wiktionary, which was launched in 2002, and Wikibooks, a collection of textbooks, launched in 2003.