"Wikipedia is a multilingual, web-based, free-content encyclopedia project based on an openly editable model." - Wikipedia
This online encyclopedia is a collaborative, cooperative effort by volunteer writers to provide up-to-date information on any subject imaginable.
Wikipedia is one of the most popular reference websites online, with millions of visitors every month. There are more than 19 million articles and 82.000 active contributors.
Wikipedia is guided by the following principles, referred to as the Five Pillars:
Wikipedia was launched on January 15, 2001 by founder Jimmy Wales. It began as a website called Nupedia (no longer a website), a peer-reviewed free encyclopedia with highly qualified contributors. Contributors to Nupedia were resistant to the idea of a wiki format, so Wikipedia was formed. Non-English Wikipedias were launched in May of 2001.