Wikipedia

Wikipedia is a free to view online encyclopedia, which is written exclusively by the collaboration of its online volunteers. One should note that this process of volunteer access does not mean that just anything can or does make its way onto the site. There are a number of online checks and balances that allow the online community to vet whether an article or its topic is Wikipedia worth.

Wikipedia, which is in fact a multi-lingual project (you choose which language version you want at its homepage) was launched as an English language project on January 15, 2001 by Larry Sanger and Jimmy Wales, as a complement to the expert-written and now defunct Nupedia.

According to Wikipedia's own article on Wikipedia "Wikipedia has more than six million articles in many languages, including more than 1.5 million in the English-language version and more than half a million articles in the German-language version."