[snip: paul davis' gtk embedding example]
well, looking at your code, i am not really sure if this is what you
mean, but the attached code shows how to embed an existing X11 window
inside a fltk window (run it, find out the XId of any existing window
(with xwininfo), and enter it in the text input. it does not matter if
the existing window is gtk, qt, motif, fltk or plain X. however there
are some problems, if you move the parent window: motif menus are opened
at the position where the window was first embedded, and for fltk menus
even the menubar buttons itself. if anybody has a suggestion on how to
solve this...
maarten
g++ embed.cxx -lfltk