MacOS 10.12 Open Source Components

Any thoughts on why they wouldn't have released this under a Github repo?

They've been publishing their source code using their own portal since before GitHub existed.

Long time ago, they used to also publish a bootable ISO of Darwin + all of those OSS packages.

They did publish an updated Darwin core / kernel a few releases back, but it seems to be closed again.

Too bad, I think someone with some determination could have gotten am hypervisor based container tech running on this. Of course the test would not run, but APIs shims could have made whole software compile (but not link). This in itself would have been very useful for a lot of people. Being able to compile in a container then link in the "real" macOS could also have been implemented, making this much more useful.

Someone should implement Vulkan for it.

Personally, I'm not a fan of centralising all open-source software on GitHub and think it's good that Apple host it themselves.

Of course, being open-source, you're more than welcome to put a copy there.