For better or worse, Wikipedia is now the most extensive single reference work ever composed. Since its launch on Jan. 15, 2001, Wikipedia has grown to roughly 20 million articles in 282 languages. (The English version of Wikipedia is the largest, comprising roughly one-sixth the total volume of articles.) Wikipedia is consistently one of the 10 most visited sites on the Internet, regardless of which service is doing the ranking.
Not bad for Plan B.
Often lost in the accolades (and criticism) of Wikipedia is an acknowledgement that it was a fallback position for a much more (oxymoron alert) traditional online encyclopedia. Wikipedia founders Jimmy Wales and Larry Sanger first collaborated on Nupedia, a free online encyclopedia written by volunteer experts whose work was peer-reviewed by accredited authorities. In its three-year history, Nupedia managed to shepherd just 24 original articles through its strenuous review process.
Frustrated with the Nupedia’s lack of adoption, Wales and Sanger ported a copy of Nupedia over to a free wiki version, to which anyone could submit or edit articles. The Wikipedia proved immediately popular, and began to accrue surprisingly good content at a rapid pace. By 2003, Nupedia was shut down in favor of its free successor. By 2007, Wikipedia was the most extensive encyclopedia ever written, displacing a reference work that had held that title for nearly 600 years.
PRIOR TO WIKIPEDIA, WHAT WORK HELD A NEAR 600-YEAR RECORD AS THE LONGEST ENCYCLOPEDIA EVER WRITTEN?