owlOWL 1.1 Web Ontology Language
MOF-Based Metamodel

Editor's Draft of 17 January 2008

This version:
Latest version:
Saartje Brockmans, ontoprise GmbH
Peter Haase, AIFB, Universität Karlsruhe (TH)


OWL 1.1 extends the W3C OWL Web Ontology Language with a small but useful set of features that have been requested by users, for which effective reasoning algorithms are now available, and that OWL tool developers are willing to support. The new features include extra syntactic sugar, additional property and qualified cardinality constructors, extended datatype support, simple metamodelling, and extended annotations. This document provides a Metamodel for OWL 1.1 based on the Meta Object Facility.

Status of this Document

This is an editor's draft, for comment by the OWL community.

Please send feedback to public-owl-dev@w3.org, which has a public archive. Bug reports can be directed there. Please check the issues list first.

Table of Contents

1 Introduction

A metamodel built on the Meta Object Facility [MOF] accompanies the OWL 1.1 specifications [OWL 1.1 Specification] and brings several benefits. Firstly, standardized mappings of the MOF to specific target languages or formats can be used to automatically build concrete representations. For example, a Java API can be derived using the MOF-Java mapping directly from the metamodel. Moreover, we can utilize MDA’s support in modeling tools, model management and interoperability with other MOF-defined metamodels.

Language mappings, also called groundings, define the relationship with the particular formalism OWL 1.1 and provide the semantics for the metamodel. Furthermore, the extensibility capabilities of MOF allow to add new modules, e.g. for rules, to the metamodel if required in the future.

A UML profile next to this metamodel can employ the extensibility features of UML2 to allow a visual notation for the modeling of ontologies for folks familiar with UML. Leveraging UML for this purpose is a first step towards a model driven approach for modeling and implementing ontologies. The validity of instances of the metamodel is ensured through various OCL constraints.

Since the ongoing standardization work for an Ontology Definition Metamodel at the Object Management Group (OMG) is specified for OWL and built on a metamodel for RDF(S), a specific metamodel specification for the new version of OWL is needed.

2 Metamodel

We provide the metamodel in Ecore, which is the MOF-like core metamodel in the Eclipse Modeling Framework [EMF]. The file is available for download here.

3 Tool Support

A prototype implementation of the MOF-based OWL 1.1 metamodel can be found here.


[OWL 1.1 Specification]
OWL 1.1 Web Ontology Language: Structural Specification and Functional-Style Syntax. Peter F. Patel-Schneider, Ian Horrocks, and Boris Motik, eds., 2006.
Meta Object Facility (MOF) Core Specification, version 2.0. Object Management Group, OMG Available Specification 1 January 2006.
The Eclipse Modeling Framework (EMF) Overview. 16 June 2005.