Given how Oracle have behaved since buying Sun it was a smart move to not use ZFS.
Networked flash array vendor Greenbytes has bought Zevo ZFS for Mac from developer Tens Complement, and gained itself a new chairman, storage industry veteran Stephen O'Donnell. Tens Complement was founded by ex-Apple engineer Don Brady and has been developing Zevo, a version of ZFS (Zettabyte File System) that was built for Mac …
Maybe, maybe not.
I think Apple has missed an opportunity by failing to have a decent enterprise range of options, as in server and good tools to manage a lot of Macs.
For a server ZFS has a lot to be said in its favour (checksums, snapshots, pairing flash intent-log and HDD mass storage, dedupe, etc), and so far Oracle has not done much to fix the crap that is their own ZFS based arrays in terms of management and monitoring. I hope that Greenbytes can pull off what Sun had hoped for, that is a good ZFS based storage system that 'just works'. Something a lot of big players seem incapable of doing in storage.
One thing that really grates me about Tens Complement's website is the way it gives no mention of how ZFS was developed by Sun Microsystems, credit should be given where it's due.
Anyway, outside of Oracle you'll find ZFS being worked on by Illumos, Joyent, Nexenta etc.
I guess it wouldn't hurt to create pools using "zfs create -o version=28 <pool>" to ensure interoperability between FreeBSD and Solaris based OS's until a clear roadmap is available (Apple, roadmap?).
You're grated by the lack of credit? No doubt, but how about zero source code? Ten's Complement never released any, and I can't find any from Greenbytes. The CDDL legally requires it.
In the meantime, the free software version of ZFS for Mac OS has always continued for all these years.