Jena is a Java framework for building Semantic Web applications. The website is in the process of moving to Apache Jena and the codebase is now hosted at Apache.
Jena provides a programmatic environment for RDF, RDFS, OWL and SPARQL and includes a rule-based inference engine.
Taylor Cowans presentation Programming the Semantic Web with Java introduces programming with Jena and Jena Beans.
Jena Tools and Utilities
Applications Based on Jena
Applications Based on Jena include TopBraid Composer and the TopBraid Suite, Talis platform, parts of the Metamatrix platform, Foresite OAI-ORE implementation, Knoodl's ontology editor, BigSwerve, SeVEn, Elastra's data centre modelling tools and the Semantic Web Environmental Directory.
The jena contributions page lists a number of applications that use jena, plus a few more are listed below.
Blackbook3 is an RDF middleware framework for integrating data and executing algorithms that relies on open standards and “best-of-breed” open source technologies, including Jena, Lucene, JAAS, D2RQ, Hadoop, HBase and Solr. Blackbook3 has a plug-and-play, loosely–coupled architecture, supports SOAP and REST interfaces, offers SPARQL and linked data endpoints and can run in environments where high confidentiality is required.
zAgile has developed an open source information integration platform (zCALM) based on Jena. It is available on SourceForge http://sourceforge.net/projects/zcalm/. It leverages SDB and also the built-in Jena reasoner. The inferred model is persisted separately from the base model and reasoning occurs in the background. Both models are accessible to queries and applications.
The latest version, zCALM 1.2 also has support for ARQ extensions.
It is manifested in two applications --
1) zAgile Wikidsmart, which is an open source semantic engine for Confluence wiki. Wikidsmart leverages zCALM server and allows users to create semi-structured content in the wiki, via semantic annotations based on formal ontologies.
2) zAgile Teamwork - which is a commercial product that demonstrates deep integration and interoperability that can be achieved between disparate applications via this platform -- in this case between Atlassian's Confluence Wiki and JIRA Issue Tracking application.
There is a sandbox where you can check out some of the capabilities of both products:
Here is a 10-minute video.
Building Jena Applications with Maven
See Using Jena with Apache Maven for instructions on building Jena, ARQ, SDB and TDB with Maven.
Run mvn dependency:tree to see the tree of dependencies Maven will use.
Maven and Eclipse
To use the Maven eclipse plugin, try:
mvn eclipse:eclipse -DdownloadSources=true -DdownloadJavadocs=true
This will generate a .project and .classpath for you.
For more help/details use:
mvn help:describe -Dplugin=eclipse
mvn eclipse:help -Ddetail=true -Dgoal=eclipse