The Qt framework was created in 1991 by a company named Trolltech (now called the Qt Company). The KDE Linux desktop is based on Qt and its increase in popularity may be a key reason why Qt development became more widespread. As a platform that's, in part, aimed at embedded devices, the typical developers using Qt are different to those for the GTK+ framework. Additionally, the tooling and support available is better developed due to their commercial backing.
The Qt framework is released in two separate distributions, one commercial and one open source (known as dual licensing). In this manner, they can support open source-compliant applications for free, while providing unrestricted usage for closed source commercial projects. Before the year 2000 (with the release of 2.2), the source code for the free distribution had been under various licenses that some...
