I am currently trying to write a cross platform GUI frontend for qemu. I have chosen to use the C++ toolkit wxWidgets, mostly because it is written in C++ and therefore object oriented, other advantages are that on Linux it uses gtk+ and it has good Windows support.
Since I don’t want to mess around with basic things like the placement of the various GUI elements, I looked around for a wxWidgets capable RAD tool. Below is a list with what I found so far.
After a short evaluation my first impression is that wxglade is not quite there yet feature wise. wxDev-C++ is impressive but depends on Dev-C++ and is therefore only available on Windows. wxFormBuilder seems to be cross platform can generate both XML resource files and C++ source code which satisfies my needs.
So right now I think wxFormBuilder is my favorite but that could change once I start using it for a longer time.
I found wxGuiBuilder which is quite neat, the main idea is to represent the GUI with a few simple relatively easy recognizable ASCII symbols. The advantage is that there is no XML and no IDE needed in order to build a good GUI.