Well, it did happen with GTK+. Go look at GLib (which underpins GTK+), it has its own string type, its own boolean type, even its own object-oriented programmi

Well, it did happen with GTK+. Go look at GLib (which underpins GTK+), it has its own string type, its own boolean type, even its own object-oriented programming scheme emulating Java-style OOP. Of course they have more of an excuse given that they wanted to stick with C instead of using C++ due to (at the time) poor language design and compiler support. But then again, that was Qt's excuse too! ;)