Hi all, I’m using osc communication to use SC and Processing at the same time. The stuff I’d like to do is to generate one routine (containing a soundfile) if I’m on the right side of the screen and another if I’m on the left side (with the mouse). until the moment of the trig everything works, but now I would like to understand how to stop the routine when the other one is activated and vice versa (perhaps with a nice fadeout). thanks 
Look into the Task class. It provides routines which can be started, stopped, paused, resumed.
Even one step further would be to look at Tdef as a way to dynamically create, start and stop tasks.