"Yesterday on the mailing list for GCC is was brought up if
Apple's Objective-C 2.0 patches for the GNU Compiler Collection
could be merged back into the upstream GCC code-base as maintained
by the Free Software Foundation. Even though Apple's modified GCC
sources still reflect the FSF as the copyright holder and are
licensed under the GNU GPLv2+, it doesn't look like Apple wants
their compiler work going back upstream any longer.
"Chris Lattner, who is Apple's chief architect of their compiler
group and also the lead developer of LLVM and Clang, came out to
say that whatever Apple pushes to their GCC branch on the Free
Software Foundation's servers they should be able to pull upstream,
but not code that's found within the open-source GCC hosted by
Apple on OpenDarwin or anywhere else."