Wireshark is moving their user interface away from GTK+ to Qt.
Making such a large change wasn’t an easy decision. It means rewriting thousands of lines of code and requires a lot of careful design. We might be the largest standalone application to make this transition (feel free to correct me below). However, I think it’s well worth it and that it’s important to the long-term direction of the project. Ultimately it came down to one thing:
Wireshark’s job is to show you what’s happening on your network. If it can’t run on your system then it’s not doing that job.