Well, I don't think you had a good look at toolkits like Qt. They provide a lot more than just a bumch of widget and window frames. There are application framew

Well, I don't think you had a good look at toolkits like Qt. They provide a lot more than just a bumch of widget and window frames. There are application framework style features in there like a very capable undo stack, abstractions over resource loading, MVC pattern implementations, plugin loading, ... Also, advanced toolkits like WPF and Qt allow you to build upon existing controls and extent and nest them in really interesting ways to create powerful UIs. You can also do pretty crazy fringe stuff easily like adding arbitrary widgets to context menus. Arbitrary widgets within list view or tree view items are probably more useful. The trick is to take as much of that composability as you can for your use case and build upon it. (I am sure other mature toolkits have similar properties, but Ibam not familiar with them to the same extent)