As far as "Apple not giving back" that too is just plain false. They do give back even at times where they don't have too. Nobody forced them for example to opensource grand central. Nobody is forcing them to continue cups support for linux, nobody is forcing them to contribute and sponsor LLVM. Every change that Apple has made to a FOSS project to suite their purposes are freely available for anyone to pull in if they desire.
No announcement yet.
LLVM Replaces libstdc++ Library With libc++