🚀 go-pugleaf

    1.  Can an X server work with two pointing devices and a keyboard?

The core protocol only handles one pointer and one keyboard, but in R4
you will find a draft standard for a protocol extension to handle a variety
of additional input devices, and a sample implementation.

    If so, do any of the toolkits support this or would we need to
    write directly to Xlib.

I am not aware of any public toolkits supporting this kind of functionality yet.

    2.  Can an X server be written to handle color systems with overlay
        planes which will contain much more than a cursor.

Yes, several vendors have done this.  There is at present no standard X
interface for overlay functionality, although there is recent progress in
this area.

    How can we switch between drawing in the image to drawing in the overlay?

Not a simple question.  Several different strategies have been proposed.

    Do we just say we are 16 (8+8) or 32 (24+8) bits per pixel?

Almost certainly not.

    3.  Is it possible to change the screen upon which a window appears
        in a multi-screen server.

The core protocol does not support this.  I suppose you could define an
extension to support it.

    4.  Can we take advantage of using a system which really does
        double buffering in hardware?

Take a look at the draft standard for multi-buffering which exists in R4.

    5.  Is there anybody else interested in seeing any of these features
        becoming an extension if they do not already exist?

Look before you Leap.