🚀 go-pugleaf

Don't know if this is the best place for this posting, but it seems likely.

We currently use non-windowing Silicon Graphics for display to a 
large screen (Sony) projector. The cable is basically T'd from the 
cpu to both the monitor and the projector. So, the entire image
displayed on the monitor goes to the projector as well. As we upgrade
to some windowing system, I wonder: Is there a way (software or
hardware) that will let me send only a specific window on the monitor
to the projector? I would like to have several windows on screen,
and be able to click on one of them and have that window expanded
to fill the large screen (projector) display. Would this be a function
of the workstation, the windowing system, external hardware, or what?
Has anyone done this? Any answers or pointers to answers would be
greatly appreciated. Thanx.