You're joking, right? You can see at a glance that this mess is only published for compliance reasons. There is no documentation at all, and most of the code consists of numerous versions of open-source libraries that have been subtly modified due to their licensing requirements, which necessitate disclosure of modifications. Good luck building any flavor of that! See: https://news.ycombinator.com/item?id=35197308
It's a shame that every new cool product/dataformat/cable/cpu/whatever researched by Apple has very little (or no) public documentation. Sure, there are lots of hackers who can test and reverse engineer those pretty quickly, but it's just unnecessary work. I don't know why Apple is so revered in hacker circles, to be honest. Not even Microsoft does this shit anymore, they're open sourcing a lot of research this decade, but they're still seen with extreme distrust. Whereas Apple was always secretive and used underhanded tactics, but it is still loved.