I've begun developing an open source OCU for JAUS systems. This project started several months ago when I was researching JAUS implementations for my day job. I ended up selecting OpenJAUS primarily because of the working vehicle simulator. ojVehicleSim compiled and ran right out of the box (repository). While looking into JAUS implementations I also noticed that there were no open source OCUs available. Later I decided to take of this project to fill that niche and for the experience of developing a GUI application - it feels quite different form the vehicle control software I'm used to writing.
Anyway, a pre-alpha version is out. It has minimal functionality - just detects other JAUS Node Managers on the network, but additional functionality is in the works. The C++ source code and a Windows binary are available on Google Code:
http://code.google.com/p/openjaus-ocu/.