OCLC has made WorldCat Works available as linked data.
Here's an excerpt from the press release:
OCLC has made 197 million bibliographic work descriptions—WorldCat Works—available as linked data, a format native to the Web that will improve discovery of library collections through a variety of popular sites and Web services.
Release of this data marks another step toward providing interconnected linked data views of WorldCat. By making this linked data available, library collections can be exposed to the wider Web community, integrating these collections and making them more easily discoverable through websites and services that library users visit daily, such as Google, Wikipedia and social networks.