I\'m looking to be able to build GUI applications quickly and painlessly as possible. I\'m competent (though not expert, and have no formal training) in C++, but have never used
Since nobody has mentioned it yet, for the sake of completeness, have a plug for the Fox toolkit. This is the one I used last time I did any C++ UI work of my own volition. There are also binding for this to Ruby and Python (the latter being many years out of date, though).
In general, the choice of a toolkit for self-directed work comes down to personal preferences for