SKOS Core
“SKOS Core provides a model for expressing the basic structure and content of concept schemes such as thesauri, classification schemes, subject heading lists, taxonomies, ‘folksonomies’, other types of controlled vocabulary, and also concept schemes embedded in glossaries and terminologies.
The SKOS Core Vocabulary is an application of the Resource Description Framework (RDF), that can be used to express a concept scheme as an RDF graph.”