What would be the most efficient way of creating a software (UI actually) that has no (and does not generate or show) windows with QT 4.0.1?

The software itself should have no visible frames, caption nor menus. The looks should be as simple as in basic linux terminal on full screen (again with no caption bar, menu or other bars), and the screen should not show anything from the background, so as user will see only black screen with text in certain locations of the screen. So it actually reminds linux with no GUI, or as a DOS as in the past years. The software is interacted with keyboard, no mouse will be used.

So basically I want to take advantage of the QT features without having the windowed looks.

The OS will be linux.

Can you guide me to the right direction on how to create this kind of interface? How should I create the background frame and the text fields?

I'll specify this even more:
The main window could be the "blank" UI window shown to user, and user controls the software via keyboard. User does not have to be able to input text via the UI. User has no ability to shutdown the UI.