Correct, there is code that will only be used on when the system is an Apple (Mac). However, Mac specific code, such as ObjC code is not allowed per Alexandre.
Huh? This statement is nonsensical. You mean objective C is not allowed in Wine. Neither is C++. It happens that the only platform on which there might be some reason to write objective C is the Mac, but it's got nothing to do with the Mac, and it's also beside the point of the original question. --Juan