The Bill & Melinda Gates Foundation is a private foundation established by Microsoft co-founder Bill Gates and his wife Melinda Gates.

Creative Commons (CC) is a non-profit organization founded in 2001 that provides free licenses for creative works.

The Wikipedia page for Global Positioning System (GPS) provides an overview of the satellite-based navigation system developed by the United States Department of Defense.

Harvard University is a renowned private research university located in Cambridge, Massachusetts, United States.

HathiTrust Digital Library is a large-scale collaborative repository of digital content from research libraries including content digitized via Google Books and the Internet Archive digitization initiatives, as well as content digitized locally by libraries.

The Internet Archive is a non-profit digital library that aims to provide universal access to all knowledge.

The Library of Congress is the national library of the United States and one of the largest libraries in the world.

A nonprofit organization, also known as a not-for-profit organization, is an entity that operates to fulfill a specific purpose or mission, rather than to generate profit for its owners or shareholders.