Difference between revisions of "Protege4Migration"

Revision as of 12:15, June 16, 2009

Overview

There are a number of differences between Protege 3.4 and 4.0. This page is designed to highlight some of the major factors that may influence which of the two systems would be most appropriate for your project at present. It will also serve as a useful reference point for identifying major features that need priority migration from 3.4 to 4.0. This list is by no means exhaustive and is only intended as an overview.

Recommendations

Frames

For working with frames-based ontologies there is only one choice - Protege 3.4 is built on a very mature and stable codebase. Frames support is not currently available in P4.x.

OWL (and RDF)

For working with OWL, there are several factors that may influence your decision on whether to use 3.4 or 4.x.

Developers

For coders writing purely OWL applications, we recommend 4.x. For applications where you cannot cleanly break away from RDF you should consider 3.4.

The 4.x framework is based on the open source, Java-based OWL API that is proving popular with many developers around the world. This makes writing or migrating code to and from other systems much more straightforward, and a larger developer community means more assistance and a more robust codebase. In addition, the OWL API supports much of the upcoming OWL 2.0 recommendation, and this is unlikely to be supported in the existing Protege-OWL API.

However, for developers that require access to the RDF model at the level of a triple store, the Protege-OWL API from Stanford is built on top of the older frames system, with RDF and OWL constructs being modeled down into Protege frames. This is much harder to develop with as all levels of abstraction are visible at the API level, but allows for more control over the relationship between the different models.

Users

For ontology developers the choice is harder as the tasks that any given user/application needs to perform can be very different. For users creating purely OWL ontologies or needing OWL2.0 features we would recommend P4.x. For users wanting access to RDF or that require particular tools that have not yet been converted, P3.x is currently still the choice.

Ultimately, P3.x is coming to a stable state such that the features of the platform are well known and the behaviour is predictable. There are many plugins available that aid particular tasks that are not currently available for P4.x. So for example, those wanting SWRL support will find the framework in P3.x much more substantial than in P4.x. Equally, users that need access to RDF(S) level constructs will need to use P3.x.

P4.x is much more lightweight, being a wholly OWL editing environment currently, and is therefore optimised considerably for dealing with even modestly large OWL ontologies in memory. The number of groups producing additional tools for visualisation, mining etc is growing. The framework uses more standard mechanisms for customisation and can therefore be more easily tuned to a particular group's workflow. P4.x will also support all OWL2.0 features, such as QCRs, role chains, additional property characteristics etc, many of which are already implemented.

Side by Side Comparison

Protege 3.x	Protege 4.0
Protege 3 Screenshot	Protege 4 Screenshot
Frames Support	Frames Support
Frames editing supported via the Protege-Frames editor	None (Protege-Frames editor has not been migrated yet)
OWL Support	OWL Support
OWL 1.0 language support	OWL 2.0 language support
OWL and RDF(S) support	Pure OWL framework
OWL and RDF(S) files are accessible via the Protege-OWL API. This API layered OWL and RDF support over the existing Frames API.	OWL files are accessible via the OWL API, which was developed at the The University Of Manchester (not the Protege-OWL API, which was used in the 3.x series). This is a very clean API that closely follows the OWL specification and the parser is optimized to be faster and use less memory.
SPARQL support	No SPARQL support yet
SWRL support through the SWRLTab	SWRL support through a basic editor and pellet for reasoning
Support for meta-modeling (allowing OWL Full)	No OWL Full
Reasoner support through HTTP DIG interface allows connection to any DIG compliant reasoner, as well as direct connection to the Pellet reasoner	Direct connection to FaCT++, Pellet and other DL reasoners for optimum speed of classification
Configuration settings stored in Protege Project files (.pprj)	Configuration settings global (No project files). Preferences persist across installations of Protege
OWL imports handled through a repository mechanism	Imports resolution from a common folder, user repositories or the web
Plugins	Plugins
Plugin framework developed at Stanford for tab widgets, slot widgets, back-ends, projects, importing, and exporting	Plugin framework has been switched to the more industry standard technology, OSGi, which allows for any type of plugin extension
Large set of plugins available, developed both in-house and externally by the Protege community	Large set of plugins available, developed both in-house and externally by the Protege community
User Interface	User Interface
Tab and slot widgets make much of user interface configurable	Plugins define all user interface elements including tabs, views, and menus making everything configurable
Support fill-in-the-blank style of setting property values in individuals	Property values of individuals are added as axioms
Access is provided to the meta model and can be used to configure the user interface	Menu and drag and drop user interface elements
Multi-user Support	Multi-user Support
Multiple users can edit the same ontology using the client-server version of Protege	None (Protege Client-Server has not been migrated yet)
Database Storage Model	Database Storage Model
Ability to store ontologies in a database provided by the JDBC database back-end	None (database back-end has not been migrated yet)