I have to try this.
It would mean I have a message sent from Processing at least once in a while.

It might be usefull, particularly while developing. Another thing that might work; When I'm trying to write something larger and re-running it often I sometimes create a hotkey that will simply kill the whole thing. In your case it would have Processing kill ChucK, then itself.

The commands are sent in the right order. But they are sent though Java processes, and I don't know how Java handles these calls.

Hmmm, would any harm be done by forcing some (short amount of) time to pass between sending the public class and the files that use it? Are the other commands ariving in order?

This works. But this is not a flexible solution from a Processing user point of view. I would prefer to use a generic setup.

Yes, clearly there is more to this but at least it works now which is a nice development after all of this strange stuff!

Kas.