> .......  Is there a
> system where you can program a word processor that does editing,
> copy+paste, page layout, etc etc, without OS-specific coding, and then
> separately decide on the on-screen menu structure, toolbar use, etc
> depending on the particular OS/GUI API at hand?  ......

This is PARTLY true of X.  I have built simple GUIs where the look and feel
changes when you change from OpenLook to Motif--without re-linking.  But
it's sloppy, in that if you design the application with Motif in mind, it
just "doesn't seem right" on Open Look--and vice versa.

Try getting on a Sparc/Solaris with OpenWindows, and invoke
$OPENWINHOME/bin/mailtool.  Then try the SAME executable with CDE
(Motif).  Everything works, but ....