I haven't yet looked at MSM. However, I do wonder if the activity/state diagrams generated from MSM based code would be convertible to equivalent sequence diagrams. In other words, I want to know if MSM does indeed create object instance and whether it creates those instances on heap, etc. In short, I am interested in the performance aspect. I have a scenario where I have two state machines - basically, protocols for the trading domain - and I am supposed to map one protocol to another and vice versa - that is, develop a message broker. I am thinking about designing a generic solution that could be used to map any protocol (all messages along with their behavior) to any protocol based on the grammar - the message strings, their sequences, etc. Can I use MSM for this kind of a problem? I did write something like this for a client a long time back but it would take me quite some time if I jump into doing that again. That does make think if Boost MSM (or StateChart?) offers a faster solution.