The above is a direct quote from http://www.semtinel.org.
And here's a screenshot of Semtinel Workbench, indicating that we're dealing with yet another application on the NetBeans Platform:
The application originates from the University of Mannheim, in Germany. In fact, you can do your thesis there (with prior NetBeans Platform experience being listed as "great") by working on this application. Here's another description of the software, together with an indication as to the reason why the NetBeans Platform was chosen:
"With our Semtinel software, we analyse the results of automatic indexing systems that map documents to appropriate thesaurus terms. For demonstration purposes, we need a simple implementation of an automatic indexing system integrated in Semtinel. The system should be somewhat modular, so that further improvements like different stemmers can easily be integrated."
Hurray again for the NetBeans Platform.