Hi Ned and Ralph,

I'm not sure I understood all of Ned's post, but this part jumped out at me..

> However, I don't think that morphs get notified when their world is about to 
> become inactive, so you'd have to add an event notification from the project,

> probably in Project>>finalExitActions...

Another possibility may be the instance-based listener for leaving a world,

  someWorld
    when: #aboutToLeaveWorld
    send: #mySelector
    to: myObject

which could be used to further notify its immediate submorphs.

 - Chris