Wikipedia

Wikipedia is a free, web-based, collaborative, multilingual encyclopedia project supported by the non-profit Wikipedia foundation. Consisting of over 20 million articles which have been written collaboratively by volunteers around the world. Almost all of the articles can be edited by anyone with internet access to the site.
Created in January 2001 by Jimmy Wales amd Larry Sanger. In its 2006 Person of the Year article, Time magazine recognized the rapid growth of online collaboration and interaction by millions of people around the world. It cited Wikipedia as an example, in addition to YouTube, MySpace, and Facebook. Wikipedia is one of the 10 most visited sites worldwide.

"Wikipedia is open to anonymous and collaborative editing, so assessments of its reliability usually include examinations of how quickly false or misleading information is removed. An early study conducted by IBM researchers in 2003—two years following Wikipedia's establishment—found that "vandalism is usually repaired extremely quickly — so quickly that most users will never see its effects" and concluded that Wikipedia had "surprisingly effective self-healing capabilities". A 2007 peer-reviewed study stated that "42% of damage is repaired almost immediately... Nonetheless, there are still hundreds of millions of damaged views." - this is directly taken from of Wikipedia.com.

The text of Wikipedia is copyrighted (automatically, under the Berne Convention) by Wikipedia editors and contributors and is formally licensed to the public under one or several liberal licenses. Most of Wikipedia's text and many of its images are co-licensed under the Creative Commons Attribution-Sharealike 3.0 Unported License (CC-BY-SA) and the GNU Free Documentation License (GFDL)