That would be based on a very simple framework which writes directly to the video to draw the underlying shadows, drop down menus, etc, not alone that, since 'Edit.com` would be written in assembler for speed in relation to drawing, this is quite ancient by today's standards, you can however take a look at PDCurses which will enable you to do this kind of thing.
The neat beauty is, PDCurses is compatible with the unix equivalent of Curses.
But, really, today, it is all about GUI and Windows....
What kind of application are you trying to do?
IIRC, from my old days, there was an object orientated framework for this using TurboVision, which has a port available with open source now, see this wikipedia entry on this TurboVision.
