Choosing between Motif, Qt, and GTK


Summary If you would like to write a control application on Windows, you have two widget sets to choose from: Qt and GTK.

One major factor in whether you should use Qt or GTK will be your programming experience: if you are already familiar with one, that will make your ArcObjects experience easier. In addition, each has both benefits and disadvantages.
Both Qt and GTK provide benefits of multi-platform availability, widespread use in newer projects, ease-of-use for programmers, and active development. Otherwise, pros and cons for each include:

Pros

GTK
Qt
flexible L-GPL license
available commercial support
 
cross-platform gui-builder

Cons

GTK
Qt
non-centralized support
less flexible and/or costly licensing
documentation is lacking
 
more difficult to set up for Windows
 
no mature gui-builder