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]
[1] http://blog.qt.digia.com/blog/2013/09/30/qt-5-2-alpha-availa... [2] https://github.com/qtproject/qtmacextras