Qt 5.3
Qt is a full development framework with tools designed to streamline the creation of applications and user interfaces for desktop, embedded, and mobile platforms.
Qt Framework
Intuitive APIs for C++ and JavaScript-like programming with Qt Quick for rapid UI creation.
Licenses Used in Qt
Qt Framework and tools are available under both open-source and commercial licenses.
The commercially licensed Qt Enterprise and Qt Mobile products contain additional functionality and productivity tools. For details, see qt.digia.com.