OntoDebug is a plugin for Protégé 5 - a free and open-source tool for ontology development.

The plugin supports the ontologist in the discovery and identification of axioms that are responsible for the inconsistency or incoherency in faulty ontologies by applying interactive ontology debugging.

Interactive ontology debugging is implemented by iteratively stating queries in the form of axioms the ontology engineer has to answer. A query can be read in the form of the question: Must the given axiom be entailed or not entailed in the intended ontology? This iterative process narrows down the set of possible faulty axioms until the final set of faulty axiom is identified.

The plugin also provides a repair interface to help the ontology engineer with the correction of the localized faulty axioms by deleting or modifying them.

The current released version of OntoDebug is 0.2.2.

You find the OntoDebug plugin in the official plugin list of Protégé 5.*

A Debugging Session with the Ontology Debugger Plugin
Animation showing OntoDebug in action


Tutorial Video

Watch a 30 minutes tutorial video about Ontology Development and Debugging in Protégé using OntoDebug:


Development Status & Plans:

  • At the moment we are working on a version for WebProtégé
  • The next release is planned to contain new features regarding test driven debugging
  • Give us your feedback if you have questions or requests and ideas for improvements


Presentation slides:

Please consider the following two presentations which give an easy-to-understand and animated overview of the features of OntoDebug:

Important: View the slides with PowerPoint in presentation mode.


* The official plugins can be installed with Protégé's Plugin check in the menu File->Check for plugins...


Comment on the Log4Shell (CVE-2021-44228) vulnerability (2022/01/10)

All released versions of the OntoDebug plugin are using the provided logging mechanism of Protégé Desktop 5.x which is SLF4J v1.7.12 in combination with LOGBack v1.1.3.
LOGBack is based on Log4J v1.x.

Therefore the OntoDebug plugin is NOT AFFECTED by the Log4Shell vulnerability (CVE-2021-44228).