Originally, ZFS was listed as one of the features for 10.6 Snow Leopard server. But, Silently, they had remove it and now comes the official news that ZFS for OS X is dead.
In previous release 10.5, ZFS was available in read-only mode. Before that, Apple released the “ZFS Beta Seed v1.1”, which allowed read-write access and the creation of zpools.
And Today, Apple announced a shutdown of the ZFS project on Mac OS Forge. No explanation was given, just the statement: “The ZFS project has been discontinued. The mailing list and repository will also be removed shortly.” Versions of the previously released source and binaries, as well as the wiki, have been preserved and development has been adopted by a group of enthusiasts.
It’s hinted that this was caused by legal issues surrounding the merger of Sun Microsystems and Oracle, which caused Apple to back away from the next-generation file system technology.