OWL Ontology Graphing Program Available as Open Source

It has been forever since I last blogged on this site (more than a year, for which I feel terrible). I have been wrapped up in work for a customer whose details are proprietary, and I was also slowly working to create (what I hope will be valuable) ontology graphing software. I wished that the work on the graphing software would have been available sooner, but better late than never ... The graphing software is called OntoGraph, is finally at a point where it is acceptable to publish, and I can freely discuss it on the blog! So, here we go ...

You can check out the work at Nine Points Solutions' GitHub repository.

OntoGraph is a Spring Boot application for graphing OWL ontologies (yes, the title says this). It lets you go from XML/RDF, Turtle and several other OWL syntaxes to a custom, Graffoo, VOWL or UML-like diagram. For example, you can go from something like this (this excerpt comes from the Friend of a Friend, FOAF.rdf ontology - you can see the complete FOAF ontology at http://xmlns.com/foaf/spec/index.rdf) ...



To ...



The above image is a VOWL rendering of FOAF.

OntoGraph is designed with a Bootstrap- and Backbone-based GUI (written in Javascript), interfacing with a RESTful API. The main program is written in Java. It operates by creating various GraphML outputs of a user-provided OWL ontology file. (Or, it also accepts a zip file of a set of ontology files). The program stores the ontologies in the Stardog triple store, then runs a series of queries to return the necessary information on the classes, properties, individuals... to be diagrammed. Layout of the resulting GraphML is handled by another program. (We recommend yEd.)

Four visualizations of ontology data can be generated:

• Custom format (defined to fit existing business or personal preferences)
• Graffoo
• UML-like
• VOWL

And, information can be segmented to display:

• Class-related information (subclassing, equivalent and disjoint classes, class restrictions, ...)
• Individual instances, their types, and their datatype and object property information
• Property information (datatype and object properties, functional/symmetric/... properties, domain and range definitions, ...)
• Both class and property information

Complete information about OntoGraph, how to run it, and issues and upcoming features are available at the GitHub repository. Also, there is a pre-publication version of a paper there, there explains OntoGraph and why it was created. (The paper will be available in the next issue of the Journal of Applied Ontology, from IOS Press.)

So, now that OntoGraph is finally published, I can start to blog about its components, design and design decisions, testing, and lots of other details. I just needed something concrete!

I hope that you find the program useful!

Andrea