What's New in Qt 4.7
Qt 4.7 provides many improvements and enhancements over the previous releases in the Qt 4 series. This document covers the most important features in this release, separated by category.
A list of other Qt 4 features can be found on the 
is a C++ library that provides the underlying engine, which translates the declarative description of the UI in QML into items on a QGraphicsScene. The library also provides APIs to bind custom C++ types and elements to QML, and to connect the QML UI with the underlying application logic written in C++.