Wikipedia: “Wikipedia … is a multilingual, web-based, free content encyclopedia project… Visitors do not need specialised qualifications to contribute, since their primary role is to write articles that cover existing knowledge; this means that people of all ages and cultural and social background can write Wikipedia articles. With rare exceptions, articles can be edited by anyone with access to the Internet, simply by clicking the edit this page link.”
And from the Wikimedia Foundation: “The mission of the Wikimedia Foundation is to empower and engage people around the world to collect and develop educational content under a free license or in the public domain, and to disseminate it effectively and globally. …the Foundation provides the essential infrastructure and an organizational framework for the support and development of multilingual wiki projects and other endeavors which serve this mission. The Foundation will make and keep useful information from its projects available on the Internet free of charge, in perpetuity.”