QML (QT Modeling Language)
QML (QT Modeling Language or some time some way say QT Meta Language), is a language, with its Javascript run-time.
QML initially designed & developed by Nokia
QML is an user interface markup (as like CSS/JSON)
QML is declarative language
You can design user interface centric application
uses "Inline JavaScript (JS)" code handles imperative aspect
It is associated with QTQuick
"UI Creation Kit" developed by Nokia within QT framework
QTQuick used for the Mobile application when "Fluid animation (60FPS) & "User experience" are critical
QML also used with QT3D to describe a 3D sense and a "frame graph" rendering methodology.
QTQuick uses QML
QTQuick is toolkit for QML (other than QTQuick there are few other kits also available for QML)...
For More info - QML Application