Qt Quick is a collection of technologies that are designed to help developers create the kind of intuitive, modern-looking, fluid user interfaces that are increasingly used on mobile phones, media players, set-top boxes and other portable devices.
Qt Quick consists of a rich set of user interface elements, a declarative language for describing user interfaces and a language runtime. A collection of C++ APIs is used to integrate these high level features with classic Qt applications.
User interfaces and their behavior are described using QML, an extension to JavaScript that lets developers and designers use a declarative syntax to specify each user interface in terms of QML elements. These elements are a sophisticated set of graphical and behavioral building blocks that can be combined together in QML documents to build components ranging in complexity from simple buttons and sliders, to complete Internet-enabled applications.
QML improves the integration between JavaScript and Qt's existing QObject-based type system, adds support for automatic property bindings and provides network transparency at the language level.
The Qt Declarative module implements the interface between the QML language and the elements available to it. It also provides a C++ API that can be used to load and interact with QML files from within Qt applications.
Qt Quick builds on Qt's existing strengths. QML can be be used to incrementally extend an existing application or to build completely new applications. QML is fully extensible from C++ through the Qt Declarative Module.