Re: Qt?
QT is a framework for GUI and applications.
It's NOT about one GUI for everything. I've seen both win9x and tile style "desktop managers" implemented using QT.
I also have used Windows XP, Windows7, Linux Desktop applications that look like any other desktop application, implemented using QT.
QT doesn't make the impossible of writing the SAME application (that's more trivial than a widget) work on a laptop or a phone usable any more than Java or MS Universal thingy does.
Even on a decent resolution 7" android tablet, a full wordprocessor done like a clone of the Windows/Linux version is horrible. You need a differently designed application, even apart from the GUI libraries for a touch screen (even if it has a keyboard cover option), compared to a keyboard & mouse GUI on a larger screen typically twice as far away. Also "touch" on a laptop or desktop screen is pretty useless ergonomically. I've tried it.
QT is real and useful alternative to Java, though not a language, it's an alternative to VB forms, c# forms, Visual C or C++ MS forms / windows frameworks etc.
The default language to use QT was always C++, but they have added more language support.