After lots of work trying to bridge Microsoft's MSMQ and Mule ESB, Claude Mamo and John D'Emic figured out a way to do it with the help of ZeroMQ. The bridge itself was easy, and took about 15 minutes to code in C#.
It was the security measures in Windows that restrict DCOM access that caused most of the issues. ZeroMQ was used as a broker between Mule and the bridge. They've also replaced the default C++ implementation of ZeroMQ with JeroMQ, the Java implementation.