Does Objective-C compile to native code or byte-code?

Question

On OS X, does Objective-C compile to native code or byte-code?

Can Objective-C programs be compiled on Linux?

Answer 1

It's native.

There is GNUstep which an Open Source implementation of the NeXT OpenStep specification written in Objective-C. Their implementation of the Cocoa API is not a direct match so a direct compilation without porting is not possible.