WorldCat, I should have guessed, is an initiative of a parent organization of libraries that has been around a long time, since 1967, and encompasses research libraries around the world. Originally known as 'Ohio College Library Center', with globalization it transfigured itself into 'Online Computer Library Center'. Here is text from the OCLC page of history:
History of OCLC
In the beginning…
In 1967, the presidents of the colleges and universities in the state of Ohio founded the Ohio College Library Center (OCLC) to develop a computerized system in which the libraries of Ohio academic institutions could share resources and reduce costs.
OCLC's first offices were in the Main Library on the campus of The Ohio State University (OSU), and its first computer room was housed in the OSU Research Center. It was from these academic roots that Frederick G. Kilgour, OCLC's first president, oversaw the growth of OCLC from a regional computer system for 54 Ohio colleges into an international network.
Expanding beyond Ohio
In 1977, the Ohio members of OCLC adopted changes in the governance structure that enabled libraries outside Ohio to become members and participate in the election of the Board of Trustees; the Ohio College Library Center became OCLC, Inc. In 1981, the legal name of the corporation became OCLC Online Computer Library Center, Inc. Today, OCLC serves more than 60,000 libraries of all types in the U.S. and 112 countries and territories around the world.