The OWL API includes various interfaces for accessing OWL reasoners. In order to access a reasoner via the API a reasoner implementation is needed. There are currently two reasoner implementations available Pellet and FaCT++. To use either of these reasoners you must download the appropriate libraries and place them in your class path.

Using Pellet

• Download the Pellet libraries from http://pellet.owldl.com/download
• Unzip the zip archive and locate the pellet.jar and aterm-java-x.x.jar libraries in the lib folder - place these two files in you class path along the jar files inside the xsdlib folder and the OWL API jar files.
• You can instantiate Pellet in the following way:
  OWLReasoner reasoner = new Reasoner();

Using FaCT++

• Go to the FaCT++ downloads page at http://code.google.com/p/factplusplus/downloads/list
  
• Download the FaCT++ OWLAPI (with Java API included) jar. Download the appropriate FaCT++ precompiled binaries for your platform (OS X, Linux or Windows).
• Place the FaCT++OWLAPI-vx.x.x.jar file in your class path (along with the OWL API jar files).
• Unzip the native libraries and ensure that the directory containing the FaCTPlusPlusJNI library [1] is in your java.library.path. For example if the libraries reside in C:\Windows\temp then you should add:
  -Djava.library.path=”C:\Windows\temp”
  to the arguments for your Java application.
• You can instatiate FaCT++ in the following way:
  OWLReasoner reasoner = new Reasoner();