dialog.[ch]xx XML-configurable dialog box.
gui.cxx, gui.h Top-level GUI functions (deprecated).
gui_funcs.cxx Implementation of internal GUI functions (deprecated).
-gui_local.[ch]xx More internal GUI functions (deprecated).
menubar.[ch]xx XML-configurable menu bar.
-mouse.cxx Old GUI mouse support (deprecated).
new_gui.[ch]xx Top-level for the GUI subsystem.
-sgVec3Slider.[ch]xx Built-in dialog for adjusting the view.
-trackball.[ch] Old mouse view support (deprecated).
David Megginson