[2] The first offering of the LC Linked Data Service was the Library of Congress Subject Headings (LCSH) dataset, which was released in April 2009.
[3] The service presents data in MADS/RDF and SKOS where appropriate, but also uses its own ontology to describe classification resources and relationships more accurately.
[2] All records are available individually via content negotiation as XHTML/RDFa, RDF/XML, N-Triples, and JSON.
[5][6] All of LCSH are crosslinked with RAMEAU [d] (Répertoire d’autorité-matière encyclopédique et alphabétique unifié), an authority file from the Bibliothèque nationale de France.
[4] The id.loc.gov site initially used a fairly lightweight Python program to serve linked data.