Qt is very very good at being non-OS-specific. Qt is also a lot more than a GUI toolkit. Until something major changes, me, my colleagues, and my company made the decision to just use Qt. You can do CLI and very very good cross-platform GUIs. Qt is underappreciated.
Qt 5.2 also adds Windows, Mac, and Android extras (platform-specific things for a native feel) [1]. For example, on Windows you can set the task bar progress, and on OS X you can use some native components, such as the toolbar. The OS X documentation is poor, but there is a GitHub repo/mirror for it [2]
The last time I built something on Qt was some 10 years ago, but it was the only time where I really enjoyed programming in C++. Underappreciated indeed.
