Originally posted by R. Belmont:
I was thinking more in terms of a native Apple one. In general people don't react well when your app requires 10 megs of Qt or GTK or whatever shared libraries so I usually build platform-native C++ UIs over a common C/C++ core codebase (Audio Overload's UI is MFC on Windows and GTK+/Glade on Linux). As far as I know there's not a similar solution on OSX.
Ah, OK - I see what you mean now. The closest thing would probably be PowerPlant X from Metrowerks, which of course isn't Apple-supplied.