QML is a user interface markup language. It is a declarative language for designing user interface–centric applications. Imperative aspects are handled by inline JavaScript code. It is associated with Qt Quick, the UI creation kit originally developed by Nokia within the Qt framework. Qt Quick is used for mobile applications where touch input, fluid animations and user experience are crucial. QML is also used with Qt3D to describe a 3D scene and a "frame graph" rendering methodology. A QML document describes a hierarchical object tree. QML modules shipped with Qt include primitive graphical building blocks, modeling components, behavioral components, and more complex controls. These elements can be combined to build components ranging in complexity from simple buttons and sliders, to complete internet-enabled programs.