[josephg]

Word on the street is that Apple's ZFS integration was mostly finished and it was going to be announced at WWDC. Sun opensourced ZFS under the CDDL. But then Oracle bought Sun, and Apple's lawyers wanted to make sure Oracle wouldn't try to sue them over ZFS somehow anyway. Negotiations between Apple and Oracle for a clear ZFS license fell through. Without legal go-ahead the feature was pulled from macos at the 11th hour and buried.

When ZFS was opensourced under the CDDL, lots of people complained that they should have chosen a clearer, more permissive opensource license. Other people said it was fine, because the license was good enough and Sun is full of good people. The way everything played out, its clear the first group's concerns were valid.

Its a huge shame. ZFS is a fantastic piece of engineering. It was ahead of its time in lots of ways. It would take years for btrfs to become usable and for apfs to appear on the scene. If not for the weird licensing decision, zfs would almost certainly have landed in the linux and macos kernels. We almost had an ubiquitous, standard, cross platform filesystem.

For more history about Sun and Oracle, this talk by Bryan Cantrill is a great watch: https://www.youtube.com/watch?v=-zRN7XLCRhc