Hi, I am new to GUI development, and am considering variety of options to start with in my project, which will involve designing some pretty complex widgetry and desktop apps. I chanced upon QT, and it looks promising.

How powerful is QT? I mean, does it provide enough functionality to design your app in any way you want, irrespective of the underlying OS? Say iTunes, which on Windows doesn't conform to the native Windows widgets styling and brings in its own set of styles and design. Is it possible to do such things in QT?