What are the real-world benefits of declarative-UI languages such as XAML and QML?

Question

I\'m currently evaluating QtQuick (Qt User Interface Creation Kit) which will be released as part of Qt 4.7. QML is the JavaScript-based declarative language behind QtQuick.

Answer 1

QtQuick is extensible via C++ plugins, actually what the Qt guys recomment is that you do the UI, Animations, Transitions etc in QtQuick/QML while all of your business logic is in C++/Qt. So this way you get the best of both worlds, you can debug your C++ code like you usually do, while at the same time making UIs becomes effortless and extremely easy.

Also another important think about QtQuick/XAML is that they are hardware accelerated, so for example you can get pretty good fps without any effort. So they are not slow at all for what they set out to accomplish.

It saves time, soo much time. I did a UI with code in 3 days, did the same in QML in 2 hours.