Qt doesn't actually "use native widgets". However, it's capable of using native API's to draw native-looking widgets pixel-perfectly, which is more than enough

Qt doesn't actually "use native widgets". However, it's capable of using native API's to draw native-looking widgets pixel-perfectly, which is more than enough on GNOME, KDE and Windows. In addition, it takes care of many cross-platform details such as button order and native dialogs, etc. On OS X I'd consider using native API's instead since I've heard so many complaints about Qt there. SWT, however, does actually use native widgets. Try out an app that uses it - it will behave the way you would expect an app to behave.