After the development of the GNU GPLv3 in 2007, the FSF (as copyright holder of many pieces of the GNU system) updated many of the GNU programs' licenses from GPLv2 to GPLv3.
Apple, a user of GCC and a heavy user of both DRM and patents, switched the compiler in its Xcode IDE from GCC to Clang, which is another FOSS compiler but is under a permissive license [REF].