I assume that Apple's OpenGL stack that uses LLVM for optimisations on low-end GPUs is still proprietary and not included in source dumps: http://en.wikipedia.

I assume that Apple's OpenGL stack that uses LLVM for optimisations on low-end GPUs is still proprietary and not included in source dumps: http://en.wikipedia.org/wiki/LLVM#Description http://en.wikipedia.org/wiki/LLVM#Description ...but I'm not really sure if that would be an example of extending LLVM or only of using it, which would make all the difference if it was copyleft software.