Wikipedia founder Jimmy Wales speaks during Wikimania, the international Wikimedia conference, in Washington in 2012. (Mandel Ngan/Agence France-Presse via Getty Images)

Jan. 15, 2001 Sixteen years ago, while working on Nupedia, an online encyclopedia written by scholars, Jimmy Wales and Larry Sanger launched a second free online encyclopedia that anyone could contribute to. Called Wikipedia, it didn’t initially attract much attention. It took about nine months before mainstream newspapers took note of it and only slightly longer for millions of students to start cribbing from it for school papers.

Wikipedia later absorbed Nupedia, and despite operating with volunteer writers and editors, it “surprised Web watchers by maturing into a popular reference site,” Leslie Walker, a tech columnist for The Washington Post, wrote in 2004. The open-source encyclopedia’s reliability has sometimes been questioned. In response, Wikipedia has developed ways to settle disputes over entries and to flag information that needs further verification.

Today, the English-language version of Wikipedia has more than 5 million articles, close to 30 million registered editors, and is among the 10 most-visited sites in the United States, according to the Web traffic data company Alexa. Wikipedia does not rely on advertising and is owned by the nonprofit Wikimedia Foundation. Pleas for donations often appear at the top of articles. In a recent appeal, Wales wrote: “People say we live in a media environment where facts have become subjective. At Wikipedia, we reject that idea. We believe facts matter. Please help us keep Wikipedia online and growing. Thank you.”

Annys Shin