KDE software is based on the Qt framework.

Qt ( " cute ", or unofficially as Q-T cue-tee ) is a cross-platform application framework that is widely used for developing application software with a graphical user interface ( GUI ) ( in which cases Qt is classified as a widget toolkit ), and also used for developing non-GUI programs such as command-line tools and consoles for servers.

Qt is most notably used in Autodesk Maya, The Foundry's Nuke, Adobe Photoshop Elements, Skype, VLC media player, VirtualBox, and Mathematica, and by the European Space Agency, DreamWorks, Google, HP, KDE, Lucasfilm, Panasonic, Philips, Samsung, Siemens, Volvo, Walt Disney Animation Studios and Research In Motion.

Distributed under the terms of the GNU Lesser General Public License ( among others ), Qt is free and open source software.

Qt is to replace Nokia's Avkon as the supported UI SDK for developing Symbian applications.

Qt is available under the following copyright licenses:

Qt Development Frameworks ( formerly known as Qt Software, Trolltech and as Quasar Technologies ) is an Oslo, Norway-based software company best known for its Qt toolkit and application framework.

Qt Development Frameworks is a wholly owned subsidiary of Nokia Corporation.

Its flagship product is Qt, a multi-platform Graphical User Interface ( GUI ) framework written in C ++.

Qt is popular with application developers using C ++ but is supported by bindings for other programming languages too, such as Python.

In 2001 Trolltech introduced Qtopia which is based on Qt.

* Symbian, which is moving towards Qt as the main development framework.

The Q Public License ( QPL ) is a non-copyleft license, created by Trolltech for its free edition of the Qt.

KDE, a desktop environment for Linux, is based on Qt.

As KDE grew in popularity, the free software community urged Trolltech to put Qt under a license ( the QPL ) that would assure that it would remain free software forever and could be used and developed by commercial third-parties.

KSVG was first developed in 2001 by Nikolas Zimmermann and Rob Buis ; however, by 2003, it was decided to fork the then-current KSVG implementation into two new projects: KDOM / KSVG2 ( to improve the state of DOM rendering in KHTML underneath a more formidable SVG 1. 0 render state ) and Kcanvas ( to abstract any rendering done within khtml / ksvg2 in a single shared library, with multiple backends for it, e. g., Cairo / Qt, etc.

" This was shortly followed by the SL-5500 ; both used ' Embedix ' - an embedded version of the Linux operating system developed by Lineo-combined with Qtopia, the Qt toolkit-based embedded application environment developed by Trolltech.

Currently Catapult, a GUI developed for the emulator that is part of the project, is being redeveloped utilizing Python and the Qt toolkit.

It was developed by Qt Software, a subsidiary of Nokia.

The Canopy Group also at one point, owned a 5. 7 % stake in Trolltech, the company which developed Qt.

Toolkits developed more recently include Qt ( 1991-, used by KDE ), GTK + ( 1997-, used by GNOME ), wxWidgets ( 1992-), FLTK ( 1998-), FOX ( 1997-) and fpGUI ( 2005-current ).

Other programmers quickly started developing KDE / Qt applications, and by early 1997, a few applications were being released.

This cost in supporting operating systems diversity can be avoided by instead writing applications against software platforms like Java or Qt.

Before the launch of the Qt Project, it was produced by Nokia's Qt Development Frameworks division, which came into being after Nokia's acquisition of the Norwegian company Trolltech, the original producer of Qt.

Only the personal edition of Qt was covered by the QPL ; the commercial edition, which is functionally equal, is under a pay-per-use license and could not be freely distributed.

As usual, the profit maximizing output ( Qt ) is determined by the intersection of the marginal cost curve ( MC ) with the marginal revenue curve for the total market ( MRt ).

* The GNU project, an essay by Richard Stallman, telling the story of Qt, Harmony, and GNOME

Much of the development efforts concentrated on increasing the emulator's portability, by rewriting assembly code in C and C ++, including a new GUI using Qt.

CLX was based on Qt by Nokia.

For example, it can be used instead of GStreamer as a backend for the Phonon media framework used by KDE and Qt.

Porten took part in the development of Qt a GUI toolkit used by Windows, Mac OS X, and X11 developers.

Some open source cross-platform toolkits, such as GTK +, Qt and WxWidgets, include widgets to embed OpenGL contents.

* Double Pendulum Simulator-An open source simulator written in C ++ using the Qt tookit.

* Qt — An application framework and widget toolkit for Unix-like systems with X11, Microsoft Windows, Mac OS X, and other systems — available under both open source and proprietary licenses.

The Kerio Connect product itself utilizes several open source products, including OpenSSL, SpamAssassin, PHP, and Qt.

* die Kurve, an open source implementation of die Kurve on Qt, hence available on most of the platforms.

* Avimator a simple open source BVH editor, ( now replaced by a Qt port, Qavimator )

Since Nokia opened the Qt source code to the community on Gitorious various ports have been appearing.

The QPL license that Qt used was free only if the program was not sold for profit and if its source code was freely available.

In addition to source compatibility with Qt, the Harmony project also aimed to add functionality such as multi-threaded applications and pluggable themes, features that Qt itself later added.

A number of frameworks can build cross-platform applications for Linux, Macintosh, and Windows from the same source code, such as Qt, the widget toolkits wxWidgets, FOX toolkit, or Eclipse RCP.