You can find the list of all the changes in the release notes, but these are a few highlights:
- Better enterprise support: A number of reported issues regarding this have been fixed. Also there is a new chapter in the documentation describing how to use the Java EE Server Facilities that jBPM jPDL offers.
- Web Service front end: The codebase now includes a starting point for those who wish to expose services of the jBPM jPDL engine as a web service. It offers limited functionality such as starting a process and continuing its execution, but interested parties can take it from there and further build on top of it. You'll find the build instructions in the jpdl/ws subfolder of the distribution and the deployment instructions in the documentation.
- Inclusion of GPD 3.1.3.SP2: The biggest improvement of the SP2 over the earlier released 3.1.3 release is that the code completion in the source page is working again.