Since the release 4.1 of JBPM you can create your BPMN models (which is stored as jBPM JPDL) using a cool Web editor.
In order to install the Signavio Web editor, all you have to do is:
From the JBPM_HOME/install launch:
This will create a Web application named jbpmeditor.war in your deploy server target.
Now start-up JBoss AS an launch the Web editor with:
(A cool video demostrating how to model a process with the Web editor is available at