I use ZFS on a dual-boot Mac to cross-mount the Linux partitions on OS X. ZFS is pretty much the only file system that allows this: The XFS OSXFUSE plugin is read-only, the ext plugin only supports ext2 with unstable write support and BtrFS can't be mounted on OS X at all.

The ZoL-derived OpenZFSonOSX port inherits ZoL's maturity, runs in kernel space and the OS X integration is really nice (Notification Center integration in ZED, custom icons, etc).

Lovin' it!

Seconded. ZFS is the only filesystem I trust with my children's baby pictures, as well as to store the git repo's for my personal projects (stuff I don't want on GitHub for a variety of reasons).

I am happy to hear that. While I certainly think ZFS is the best filesystem available for storing this kind of data, i would like to add a word of caution that ZFS is not a replacement for backups. I elaborated on this in one of the supplementary blog posts:

https://clusterhq.com/blog/file-systems-data-loss-zfs/#disk-...

Absolutely. I have a regular backups strategy that also backs up to a ZFS system :).