Protégé-OWL has become the default open-source editor for the Web ology Language, OWL (See also ). It was developed collaboratively between University of Manchester and Stanford University based on the earlier Protégé that used the frame-based formalism based on OKBC.
Protégé is an open-source environment that provids a framework for “plugins” either for specific applications or alternative editing tools and views.
Protégé-OWL currently exists in two released versions – version 3 and version 4 – plus an experimental Web/browser based version using Google Web Toolkit (GWT).
Version 3 is limited to the original OWL 1.0 specification but supports multi-user access and a number of plugins not yet ported to version4 , most importantly the SWRL plugin and the PROMPT ontology comparison tools. Version 3 is layered over the original frames environment and the original serialisation of OWL in RDF/XML.
Version 4 is a complete re-write including the full OWL 2 specification and built on the new OWL 2 API and a range of plugins for easy creation of OWL ontologies – e.g. outline and spreadsheet like functionality, better search facilities, and tighter integration with OWL reasoners, etc. Multi-user and web versions of Protege-OWL-4 are under development but not yet released (as of Jan 2010), as are versions of the most popular plugins for version 3.
The lists of available plugins for Proteégé-OWL-4 can be found on Manchester’s CO-ODE site.
A key resource for understanding both OWL and the use of Protégé-OWL is the Protégé OWL Tutorial which is also probably the best overall introduction to OWL for general users.
Neither the official OWL abstract syntax nor the OWL XML syntax is easy to read or use. Protégé-OWL introduced a new simplified and less verbose syntax: e.g. “some” and “only” rather than “someValuesFrom” and “allValuesFrom”. The Manchester Syntax has now been accepted by W3C as part of the official Official OWL 2 standard.
(See OWL Syntaxes)