Qt4

Qt

GUI designing in Qt Creator using the embedded Qt Designer
Original author(s)	Haavard Nord and Eirik Chambe-Eng
Developer(s)	Trolltech (1991–2008) Nokia (2008–2011) Qt Project (2011–present) Digia (2012–2014) The Qt Company (2014–present)
Initial release	20 May 1995; 22 years ago (1995-05-20)
Stable release	5.9 (31 May 2017; 9 days ago (2017-05-31))
Repository	code.qt.io/qt/qt.git
Development status	Active
Written in	C++
Operating system	Android, iOS, Linux (Embedded, , X11), macOS, Windows, Windows Phone, …
Platform	Cross-platform
Type	Application framework
License	Qt Commercial License GPL 2.0, 3.0 LGPL 3.0
Website	www.qt.io

Qt (/kjuːt/ "cute") is a cross-platform application framework that is used for developing application software that can be run on various software and hardware platforms with little or no change in the underlying codebase, while still being a native application with native capabilities and speed. Qt is currently being developed both by The Qt Company, a company listed on the Nasdaq Helsinki Stock Exchange, and the Qt Project under open-source governance, involving individual developers and firms working to advance Qt. Qt is available with both commercial and open sourceGPL 2.0, GPL 3.0, and LGPL 3.0 licenses.

Qt is used for developing multi-platform applications and graphical user interfaces (GUIs); however, programs without a GUI can be developed, such as command-line tools and consoles for servers. An example of a non-GUI program using Qt is the Cutelyst web framework. GUI programs created with Qt can have a native-looking interface, in which case Qt is classified as a widget toolkit.

It has extensive internationalization support. Non-GUI features include SQL database access, XML parsing, JSON parsing, thread management and network support.