OT SOFTWARE to project and switch between a webcam and a real timescreen shot

[Rick Walker <looppool@cruzio.com>]

I'm setting up a video teaching studio at my home
and was told that software exists that allows one to
project your computer screen in real time to
someone on video chat.

What I want to do is to be  able to switch between a
video cam on me (or a remote camera)  and
real time movies of my computer screen.

does this exist?

Does anyone have any experience doing this?

I'd be greatly in your debt to know what you all know.

Thanks for bearing with this offtopic post,   but I'm going to be
offering live looping,   rhythm intensive,  computer sound design
and arrangement/composition/improvisation/creativity lessons
so it might actually be ON topic if I can get it going, soon.

yours,   Rick Walker