BRL-CAD has an interactive geometry editor called MGED. It's often the starting point for beginners and allows creation and manipulation of models using commands. When MGED is invoked, it creates 2 windows: a text-console command window and an interactive graphics window. If the user closes the text-console command window, they are left with the interactive graphics window. There is presently no way (correct us if we're wrong) to get the text-console back without restarting mged. A good way to test this is to run in classic mode and run the 'gui' command:

 sushi:~ morrison$ mged -c test.g
 BRL-CAD Release 7.22.0  Geometry Editor (MGED)
     Fri, 24 Aug 2012 00:02:42 -0400, Compilation 6
     morrison@sushi.local:/usr/brlcad/rel-7.22.0

 attach (nu|X|ogl)[nu]?
 mged> gui

This task involves adding some mechanism, perhaps a simple key binding, to the graphics window so that you can get the command window back on-demand.

Code:

• src/mged/mged.c
• src/tclscripts/mged/openw.tcl