Pellet is an open-source Java based OWL DL reasoner. It can be used in conjunction with either Jena or OWL API libraries. Pellet provides functionalities to check the consistency of ontologies, classify the taxonomy, check entailments, give explanations, and answer SPARQL-DL queries.
Pellet requires a JVM compatible with Sun's Java version 1.5 or above. You can download Sun's JVM or SDK at http://java.sun.com. If you have Java installed on your machine just unzip the Pellet distribution file to start using it.
Pellet comes with a simple command line interface to demonstrate some of its capabilities. This program provides options to check the consistency of an ontology, find unsatisfiable concepts, display the class hierarchy (with instances if desired), answer a SPARQL-DL query.
To run the command line version simply execute the following command
pellet.sh help
Running this command will print the options available.
You can access Pellet from Java applications using one of two different APIs designed to support Jena and OWL API libraries. The functionality in both packages is almost equivalent. See the javadocs for the details of interfaces and check out the examples directory for sample code. You can find the answers to some Frequently Asked Questions in Pellet FAQ.
If you are interested in a GUI, you can use SWOOP which uses Pellet for reasoning.
If you are starting from a distribution, Pellet comes pre-built, with all the required libraries included in the zip file.
To use the Pellet build system, you need Apache Ant, version 1.5 or above. You can download a copy of Ant at http://ant.apache.org/.
Running 'ant' in the trunk directory should be enough. The resulting files are placed in the directory dist/. Running 'ant zip' will build a source and binary distribution in the file dist/pellet-{date}.zip.
The ant target 'zip' will build the file dist/pellet-{date}.zip. The ant target 'release' will build the file dist/pellet-{version}.zip. You can change the version string by editing the build.xml file. The distribution file will include the source code, the Pellet jar file, and all supporting jar files found in the lib/ directory.
There is a mailing list for questions and feedback: pellet-users@lists.owldl.com. You can subscribe to the list and see the archives here: http://lists.owldl.com/mailman/listinfo/pellet-users.