There's also the theory that it was Jonathan Schwartz's (Sun's then CEO) "pre-announcement" that led Steve Jobs to throw it all in the bin:

> In fact, this week you'll see that Apple is announcing at their Worldwide Developer Conference that ZFS has become the file system in Mac OS 10

That was the theory I’d always heard, but it seems like such a huge thing to pull last minute out of spite.

Some of the other comments about licensing issues make more sense, although that announcement may have been the final straw.

If it was one thing, I would agree but Apple/Jobs was known to do this, look at nVidia history as well.

The licensing terms wasn't a dealbreaker on its own, both Oracle and Apple could've come up with a different agreement (like Oracle would protect Apple if they were sued) but that announcement was just a massive no-no regardless of how friendly the company is with Apple.

I know they tended to do this, but ATI was a pretty direct replacement to nVidia, so the Switch wasn’t as big a deal. They’ve certainly done it with other things too.

Giving up on ZFS meant they had to stick with the ancient HFS+ and start a VERY long project to make a new FS.

In the long run, they ended up with their own FS that they can scale from all of their platforms (tvOS, iOS, macOS, watchOS) and pulled it off without any serious issues, which is impressive on its own.

It's going to be interesting to see how well they optimize APFS in the following years since the current performance level isn't that much better.

It’s fits their tendency to want to keep everything in house as well.

But I would have preferred to have ZFS while they worked on their own FS. And I still want data integrity to protect against bit rot whichever APFS does t provide.