Qt Development Frameworks

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The Qt Company

legal form Division of Digia , listed as "Qt Group" on the stock exchange
ISIN FI4000198031
founding 1994
Seat Helsinki , Finland
management Juha Varelius
Number of employees 238 (September 2007)
Branch Software development
Website www.qt.io

The Qt Company is a division of Digia , which was created by Nokia in 2008 when Nokia bought the Norwegian software company Trolltech , which produces programming environments and program libraries . Trolltech (formerly Quasar Technologies ) was founded in 1994 by Haavard Nord and Eirik Chambe-Eng (both Co-CEOs) and was listed on the Oslo Stock Exchange from 2006 to 2008 . In 2012 it was sold to the Finnish software company Digia. In May 2016, the Qt Company announced that it was separating from Digia and trading on NASDAQ Helsinki under the symbol QTCOM.


The development of the main product " Qt " began in 1992. Two years later, Trolltech was founded in Oslo , Norway . In 1996 the European Space Agency was the first customer, they used both Qt / Windows and Qt / X11 . In June 1998 Trolltech signed a declaration which assured the “ KDE Free Qt Foundation” (represented by KDE eV) the availability of a free version of the Qt toolkit (“Qt Free Edition”). Should Trolltech stop developing the free version or not deliver an update for more than twelve months, the KDE Free Qt Foundation would have the right to put the currently available source code under the BSD license .

In the following two years branches were established in Brisbane (1999, Australia) and Santa Clara (2000, USA). In October of the same year Trolltech also changed the license model of Qt 2.2 and all following versions: The terms of the “ GNU General Public License ” (GPL) and the “Qt Public License” (QPL) now apply . Qt is thus dual-licensed and fully complies with the conditions for free software, but not all components were relicensed: Qt / Windows, for example, was not subject to the new regulation and remained a fee for all developers. In 2002 the new products Qtopia and Qt / Mac appeared. In the following year Qt / Mac was placed under the GPL and the new product Teambuilder (a tool for parallel and distributed compilation of source code written in C ++ or C in networks) was published. With Qt Solutions, a new development department for commercial customers was created, solutions developed there occasionally find their way into Qt with a long delay. In July 2004 the agreement with the KDE Free Qt Foundation was renewed.

A year later the subsidiary in China was founded and Trolltech announced that with the release of Qt Version 4.0, the Windows port would also be placed under the GPL. After the release of the first stable version on June 28, 2005, the number of Qt-based open source projects increased, the KDE team began porting KDE to Qt4 and announced a large number for the end product " KDE SC 4 " new functions. In 2006 Trolltech opened further branches in Berlin and Munich .

In July 2006, Trolltech went public on the Oslo Stock Exchange under the symbol TROLL . The issue price was € 17.50 and rose to over € 21 on the same day, but in the following months the share fell significantly and the price fell below the issue price.

Trolltech was acquired by Nokia on June 17, 2008 and renamed to Qt Software on September 29, 2008. The former Trolltech has not been listed on the Oslo Stock Exchange since June 18, 2008. Since August 11, 2009 the division has been called Qt Development Frameworks .

On January 14, 2009, the GNU Lesser General Public License (LGPL) was added to Qt 4.5 and following .

In March 2011, the part of the business that deals with licensing and services for around 3500 customers was sold by Nokia to the Finnish software house Digia . A month earlier it was announced that Nokia will not use the Qt software for its future Nokia Windows Phones.

In August 2012, Digia took over Qt completely from Nokia and paid 4 million euros for it.


Qt (library)
most important product, a program library including a development environment for cross-platform software development . The programs are primarily written in C ++ and can run under Unix / Linux , Microsoft Windows and Macintosh , among others . Essential parts of KDE are based on Qt, as are Google Earth and Skype .
Qt Creator
a C ++ based cross-platform development environment for Qt.
Qt Extended (formerly Qtopia )
a graphical user interface for PDAs , cell phones and other embedded devices. The free PDA surface OPIE is based on it . The development was stopped and the range of functions was integrated into Qt under the name Qt Mobility .
a cross-platform toolkit for implementing scripting capabilities in Qt programs (formerly implemented by Qt Script for Applications (QSA)).
a Makefile generator for creating a software project, similar to automake .
Team builder
enables distributed compilation of code written in C ++ or C.
a mobile phone based on Qtopia which, in contrast to the Neo1973, was only used for product demonstrations .

Corporate structure

The last 238 employees (as of September 2007) held the largest share of the company until the end of January 2008. Trolltech supports open source projects, especially the KDE project, through support, developer programs, programming competitions and paid software developers.

On January 28, 2008 Trolltech announced the sale to Nokia in a notice. The purchase offer of 843.6 million crowns (about 105 million euros) was accepted by the Trolltech board of directors and supported by the shareholders with a total of more than two thirds of the shares. The company's listing ended in June 2008.


The employees are granted a so-called Creative Friday , every Friday during working hours they can work on a project that is not directly related to Trolltech - a prerequisite is an informal review by management.

Many current and former Trolltech employees come from the open source environment and continue to work on such projects:

Web links

Individual evidence

  1. a b Harald M.genauck: Digia takes over Nokia's remaining Qt activities . Report to heise.de. August 9, 2012. Retrieved October 10, 2012.
  2. ^ NASDAQ Helsinki Welcomes Qt Group Plc . May 4, 2016. Retrieved June 10, 2016.
  3. ^ KDE Free Qt Foundation. Retrieved April 3, 2010 .
  4. computerwoche.de: "Trolltech is on the stock exchange", July 5, 2006
  5. Nokia press release: Nokia completes Trolltech acquisition
  6. www.trolltech.com/about ( Memento of the original from May 26, 2012 in the web archive archive.today ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , accessed September 30, 2008 @1@ 2Template: Webachiv / IABot / trolltech.com
  7. Archived copy ( memento of the original from February 22, 2012 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / qt.nokia.com
  8. LGPL License Option
  9. Digia press release of March 7, 2011. (Digia is a company listed on the Helsinki Stock Exchange .)
  10. Nokia to developers: no Qt for Windows Phone development Thomas Ricker, published on February 11, 2011
  11. https://www.heise.de/newsticker/meldung/Digia-Schnaeppchenpreis-fuer-Qt-und-Z Zusammenarbeit-mit-KDE- 1665979.html