Objective-C, Unversioned
We’ve had internal discussions and have explicitly decided not to version the language any more. Instead of “Objective-C 2.0” or some such, there is now just “Objective-C as of Xcode 4.4” or “Objective-C in LLVM Compiler/Clang 4.0”.
If you’d like to reason about or conditionalize your code on various language features, please use the Clang feature checking macros.
It makes sense to check for features when writing code, but I think version numbers are useful for talking about, documenting, and referencing the language.
Are three version numbers useful, though? IDE, Compiler, Language? It's a source of confusion.