Are you referring to the move to OS X? Apple ran the previous operating system within the new operating system just to run those old apps, and Carbon was provid

Are you referring to the move to OS X? Apple ran the previous operating system within the new operating system just to run those old apps, and Carbon was provided as a transitional API for many years. I'm not sure what this has to do with anything, really. A backwards compatibility argument (whatever it may be) doesn't make sense here, as Clang has been designed to be backwards compatible with GCC-based projects.