The SKOS API is a Java interface and implementation for the W3C Simple Knowledge Organisation System SKOS. For more information about SKOS see here. An implementation of the SKOS API is provided which uses the OWL 2 API, at present you will need to obtain the OWL API seperately from the OWL 2 website. [UPDATE 12-09-2011] The current release of the SKOS API has been deprecated, a new version_3 developer branch is available in the SVN repository that works with the latest OWL API v3.

For more information please contact the user group at

The SKOS API is open source and is available under the LGPL License

The SKOS API includes the following components:

  • An API for the major SKOS constructs and an efficient in-memory reference implementation based on the OWL 2 API
  • Abstract data model for working for SKOS that avoids commitment to any of the concrete syntaxes, such as RDF
  • RDF/XML parser and writer
  • OWL/XML parser and writer
  • OWL Functional Syntax parser and writer
  • Turtle parser and writer
  • Support for extending the underlying SKOS data model via the OWL 2 API
  • Support for integration with reasoners such as Pellet and FaCT++
  • Range of convenience methods for working with SKOS

The initial work was developed as part of the CO-ODE project and the EU Sealife project