From Semantic Web Standards

Web Ontology Language (OWL)


The W3C Web Ontology Language (OWL) is a Semantic Web language designed to represent rich and complex knowledge about things, groups of things, and relations between things. OWL is a computational logic-based language such that knowledge expressed in OWL can be exploited by computer programs, e.g., to verify the consistency of that knowledge or to make implicit knowledge explicit. OWL documents, known as ontologies, can be published in the World Wide Web and may refer to or be referred from other OWL ontologies. OWL is part of the W3C’s Semantic Web technology stack, which includes RDF, RDFS, SPARQL, etc.

The current version of OWL, also referred to as “OWL 2”, was developed by the [W3C OWL Working Group] (now closed) and published in 2009, with a Second Edition published in 2012. OWL 2 is an extension and revision of the 2004 version of OWL developed by the [W3C Web Ontology Working Group] (now closed) and published in 2004. The deliverables that make up the OWL 2 specification include a Document Overview, which serves as an introduction to OWL 2, describes the relationship between OWL 1 and OWL 2, and provides an entry point to the remaining deliverables via a Documentation Roadmap.

Recommended Reading

As can be seen from the above mentioned Documentation Roadmap, OWL 2 is normatively defined by five core specification documents describing its conceptual structure, primary exchange syntax (RDF/XML), two alternative semantics (Direct and RDF-Based), and conformance requirements. Three additional specification documents describe optional features that may be supported by some implementations: the language profiles, and two alternative concrete syntaxes (OWL/XML and Manchester).

These documents are, however, all rather technical and mainly aimed at OWL 2 implementers and tool developers. Those looking for a more approachable guide to the features and usage of OWL 2 may prefer to consult one of the user documents, which include a Primer and a Quick Reference Guide.

A number of textbooks have been published on OWL, and on Semantic Web in general. Please, refer to a separate page listing some of those, as maintained by the community. That list also includes references to conference proceedings and article collections that might be of general interest.

Tools that are listed as relevant to OWL

(Note that you can browse tools per tool categories or programming languages, too.)

Last modified and/or added

The description of the following tools have been added and/or modified most recently.

All relevant tools

This is a list of all tools listed on this wiki, and that are marked as relevant to OWL.

  • AllegroGraph RDF Store (programming environment, reasoner, triple store, development environment, rdfs reasoner). Directly usable from Java, LISP, Python, Prolog, C, Ruby, Perl
  • Apache Jena (programming environment, reasoner, triple store, rdfs reasoner, rule reasoner, owl reasoner, parser). Directly usable from Java
  • Cowl (programming environment, parser). Directly usable from C, C++
  • FRED (rdf generator, tagging, knowledge graph extractor).
  • Mobi (programming environment, development environment). Directly usable from Java, Javascript
  • Ontop (reasoner, rdfs reasoner, owl reasoner, rdf generator, sparql endpoint, rdb2rdf, converter). Directly usable from Java
  • Ontopic Studio (reasoner, rdfs reasoner, owl reasoner, rdf generator, sparql endpoint, rdb2rdf, converter).
  • OpenLink Virtuoso (reasoner, triple store, rdfs reasoner, owl reasoner, rdf generator, sparql endpoint, rdb2rdf). Directly usable from Java, Python, C, Ruby, Perl, PHP, Javascript, C++, ActionScript, Tcl, Obj-C
  • Oracle Spatial and Graph 19c (reasoner, triple store, owl reasoner). Directly usable from Java
  • GraphDB (reasoner, triple store, rdfs reasoner, owl reasoner, sparql endpoint). Directly usable from Java, C
  • RDFox (reasoner, triple store, rdfs reasoner, rule reasoner, owl reasoner). Directly usable from Java, C++
  • Altova's SemanticWorks (editor, development environment).
  • Spyder (sparql endpoint, rdb2rdf).