• English

OCLC provides downloadable linked data file for the 1 million most widely held works in WorldCat

OCLC WorldCat

OCLC has published bibliographic linked data for the most widely held works in WorldCat. This downloadable file —representing nearly 1.2 million resources—contains approximately 80 million linked data “triples,” the term for the most granular relationship possible between discrete pieces of information.

“This is an important step for libraries and linked data,” said Richard Wallis, OCLC Technology Evangelist. “Organizations wishing to develop linked data services can experiment with this data set before going into full development. They’ll also be able to stress-test new services using a very large and important set of up-to-date, linked library data. We are really interested to see what people will do with this data.”

The linked data is provided as RDF serialization, and uses the ontology as well as library extensions to that OCLC has been working on with members and partners over the last year. It is being made available, under an ODC-BY data license, in a single, 1-gigabyte, compressed (GZip) file.

While WorldCat contains bibliographic records for more than 275 million items, the choice was made to select the most widely held materials for this release in order to help keep the file at a manageable size. Jeff Young, the OCLC Research software architect who did much of the modeling necessary to generate the linked data file, explains, “To make the cut, a resource had to be held by at least 250 libraries. This seemed to us to be a good balance between providing widely useful data while making it reasonably manageable for most uses.”

In June 2012, OCLC added tags to records, improving the way in which library information is represented to search engines. OCLC has also developed linked data resources for the Dewey Decimal Classification System, FAST (Faceted Application of Subject Terminology) and the VIAF(Virtual International Authority File) service. The release of these 1.2 million records as linked data is the next step in OCLC's linked data strategy.

To take part in the discussion about library linked data, sign up to participate in the linked data discussion forum on the OCLC Developer Network or send your thoughts via e-mail to

Full Press Release