Qt is developed by an open source project, the Qt Project, involving developers as individuals and from firms working to advance Qt, such as Nokia, Digia, and others. Before the launch of the Qt Project, it was produced by Nokia’s Qt Development Framework division, which came into being after Nokia’s acquisition of the Norwegian company Trolltech, the original producer of Qt. In February 2011 Nokia announced its decision to drop Symbian technologies and base their future smartphones on Microsoft platform instead. One month later Nokia announced the sale of Qt’s commercial licensing and professional services to Digia although Nokia was to remain the main development force behind the framework at that time. On 9 May, it was announced on the Qt Labs website that the groundwork was being laid for the next major version of Qt, with the expectation that Qt 5 would be released in August 2012.
On 9 August 2012, Digia acquired Qt software technologies from Nokia. About 125 Qt developers will be transferred to Digia, with the immediate goal of bringing Qt support to Android, iOS and Windows 8 platforms.
Qt moves like this:
Trolltech —> Nokia –> Digia