There's never a question Wikipedia hasn't been able to answer for me. 

A free, collaborative, multilingual Internet encyclopedia.

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.  In collaboration with a network of chapters, 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.

Wikimedia Foundation

PBS's mission is to inform, to inspire, and to educate.

PBS and more than 350 local stations offer every American opportunities to experience new places, explore new ideas and discover new worlds.

Brian Lee

Wikimedia Foundation

Public Broadcasting Service