Where to find vocabularies

This page lists resources for finding vocabularies. Note that there is no central repository of vocabularies on the semantic web.

You can also get good and up-to-date advice by asking what people are using on the mailing lists such as the Semantic Web mailing list, the RDFa list or the Linked Data mailing list.

NOTE: the list below is not ordered by any measure of importance. In fact, it is ordered alphabetically.

American Society for Indexers

List of Online Thesauri and Authority Files

Cognition

Cognition.com is a definition level organization of terms.

Common Tag

Common Tag is an open tagging format developed to make content more connected, discoverable and engaging. Click here [1] for companies involved in the development of Common Tag.

eXtended WordNet

eXtended WordNet uses WordNet as a basis, and adds some key enhancements. "In the eXtended WordNet the WordNet glosses are syntactically parsed, transformed into logic forms and content words are semantically disambiguated." (description from the site)

Falcons Concept Search

Actively maintained Semantic Web search engine for finding ontologies.

http://iws.seu.edu.cn/services/falcons/conceptsearch/

The Getty

The Getty vocabularies are vocabulary databases produced and maintained by the Getty Vocabulary Program

Library of Congress Authorities and Vocabularies

Here is the download page for 342,684 subject authority records in compressed files for both RDF/XML and N-Triples serializations maintained by LC Authorities and Vocabularies Service

Open Ontology Repository (BioPortal)

Open Ontology Repository is the design document behind the OOR system, which is currently used at BioPortal. The same technology could be used to set up other ontology repositories in different domains.

rdfs.org

Currently hosts SIOC, RDF-Resume and others vocabularies.

http://rdfs.org http://rdfs.org/ns

SchemaCache

Talis's cache with search of vocabularies.

http://schemacache.test.talis.com/

Schemaweb.info

Seems more or less actively unmaintained since 2005, but vocabularies still added in 2007.

http://schemaweb.info/

Sindice

Semantic search engine with an actively maintained large index of ontologies and individuals. The interface itself doesn't allow to query for an ontology with a particular name for a class, but it's possible with the API..

http://sindice.com

Swoogle

More or less seems not updated, by still useful sometimes for finding ontologies.

http://swoogle.umbc.edu/

Taxonomy Warehouse

http://www.taxonomywarehouse.com/

Free and fee-based vocabularies licensed from a variety of providers.

Vocab.org

Hosts a large amount of vocabularies, actively maintained.

http://vocab.org/

WordNet

WordNet is a large lexical database of English. The WNWS WordNet Web Service produces XML output to word queries of the WordNet database.

See also, eXtended WordNet, which uses WordNet as a basis, and adds some key enhancements.

xmlns.com

Hosts FOAF and WOT vocabularies.

http://xmlns.com/