Ontology
A formal OWL/RDF knowledge representation (e.g. FOAF, Schema.org)
39 standards
BBC Ontologies
Fourteen interlinked RDF ontologies powering linked data across BBC Sport, News, Music, and more.

Bibliographic Ontology
(BIBO)An OWL ontology for modeling citations, documents, and scholarly references on the Semantic Web.
Bibliographic Reference Ontology
(BiRO)An OWL ontology for describing bibliographic references and their ordered collections within citing works.
Chemical Entities of Biological Interest
(ChEBI)An ontology classifying small chemical compounds by structure, role, and biological activity.

Citation Typing Ontology
(CiTO)An ontology that captures the rhetorical and factual reasons one publication cites another.

Data Catalog Vocabulary
(DCAT)A W3C vocabulary for describing datasets and data services in federated catalogs on the web.
Data Privacy Vocabulary
(DPV)Provides structured concepts for describing personal data processing, privacy rights, and legal bases.
Data Quality Vocabulary
(DQV)Provides an RDF vocabulary for describing and assessing data quality dimensions, metrics, and certificates.
DBpedia Ontology
(DBO)A cross-domain ontology derived from Wikipedia infoboxes, covering 768 classes and 3,000 properties.

Description of a Project
(DOAP)An RDF vocabulary for machine-readable descriptions of open-source software projects.
FaBiO, the FRBR-aligned Bibliographic Ontology
(FaBiO)An ontology for publishable entities aligned with the Work-Expression-Manifestation-Item model.

FOAF Vocabulary Specification
(FOAF)A pioneering Semantic Web ontology for describing people, their relationships, and online accounts.

Gene Ontology
(GO)The most widely used ontology for annotating gene function across all living species.

GeoNames Ontology
Provides linked data URIs and semantic descriptions for over 11 million global place names.

GeoSPARQL
(GeoSPARQL)Adds spatial query functions and a geometry ontology to SPARQL for the Semantic Web.
GoodRelations Ontology
(GR)Describes products, services, prices, and business details as structured linked data for e-commerce on the web.
Human Phenotype Ontology
(HPO)A controlled vocabulary of over 18,000 clinical features for rare disease diagnosis and genomics.

Hydra Core Vocabulary
(Hydra)Describes hypermedia-driven Web APIs in machine-readable form, enabling clients to discover operations at runtime.
Lexicon Model for Ontologies (OntoLex-Lemon)
(OntoLex)Represents lexicographic and linguistic data as RDF, linking lexical entries to ontology concepts and meanings.
Music Ontology
(MO)An OWL ontology modeling the full lifecycle of music from composition to recording to release.

Open Digital Rights Language
(ODRL)Expresses machine-readable policies for permissions, prohibitions, and obligations over digital content.
PROV: Provenance Data Model and Supporting Definitions
(PROV)Models the provenance of data and things by tracking entities, activities, and the agents responsible.
Provenance, Authoring and Versioning Ontology
(PAV)Tracks provenance, authorship, curation, and version history of resources using lightweight RDF properties.
Quantities, Units, Dimensions and Types Ontology
(QUDT)An ontology for quantities, units of measurement, and dimensions used across science and engineering.

RDF Data Cube Vocabulary
Publishes multi-dimensional statistical and aggregate data as linked data using RDF and SDMX concepts.