> ... how do you balance that out?

Not sure what you're asking?

"Significantly" doesn't seem to be correct. At least, not for the (GPL licensed?) stuff that's been stuck on ancient versions for many years.

Though they have (from my rough memory) made some contributions back to FreeBSD where it seemed to make sense.

All that aside, the point is that they didn't build their platform "almost from scratch".

They assembled a lot of pre-existing pieces (many OSS), then built on top of that. It's a common way of doing things.

What I’m suggesting more than asking is, when you say that open source has lifted their development burden, it makes it sound like it’s a unidirectional taking.

And sure, some might be freeloading. But they also do contribute quite a bit to open source. https://opensource.apple.com/

I know your response was more to correct the “developed from scratch” but I still think it’s important to note that it’s not unidirectional. Even in the development of their own platforms, you can find old Usenet discussions of how they were feeding things back. I think they could have gone their own route but Unix compatibility was important.

The history of Next, Apple, and the open source community is very intertwined and unfortunately cannot be reduced so easily.

> ... it’s important to note that it’s not unidirectional.

A somewhat unexpected factoid about Apple and OSS, is that Apple doesn't seem to provide hardware to any OSS projects they didn't themselves create.

Not even Homebrew, who (to my thinking) should have been first in line due to the immense benefit they used to provide Apple's users.

Webkit (and subsequently Blink/Chromium) and LLVM especially did have a significant impact though.

> didn't build their platform "almost from scratch".

Well, no, it’s of course relative I meant that compared to Valve/Steam they did. And it’s not like iOS/macOS is just a collection of open source components slapped together with some small proprietary layer on top. At this point it’s mostly proprietary stuff they had to build effectively from scratch over the years with some open source components here and there.