I have written a fair amount of software in Qt. It has been clear to me from the actions of the Qt company (via the amount they charge for it, getting rid of indie plans which allowed you to use it Qt for ~350 bucks a year vs the $5508 a year that they have chosen the strategy of milking the captive users that Qt has rather than expanding Qt out and courting new users. For better or for worse at this point I see closed source Qt going the way of Delphi. Qts long term survival depends on a viable and vibrant OSS fork.