Synth target spawning external processes

Hello

I was wondering if anyone has written some Tcl/Tk code to spawn external 
processes when running the synth target. We currently have a few 
external processes to simulate a GPS receiver among other things. These 
processes are currently started independent of ecossynth and need to be 
up and running when starting the application. This works, but it'd be 
nicer to automatically spawn these processes when the application is 
started, especially when doing so from the debugger. I think I'll wrap 
something up unless there is already a solution out there which I can 
build upon.

Best regards,
Simon