Also, it's basically possible to zoom/scale a "normal" QWidget's contents as well (see here for example), but that would mean to always use derived widget classes in order to overwrite their paintEvent()'s (and wheelEvent()'s). I don't think that's worth the hassle since setting the GUI font has (nearly) the same effect.

A mind is like a parachute. It doesn't work unless it's open. [Frank Zappa]