I was googling and somehow i found this zfs-59 folder in darwinsource. I located the tarball for the source, downloaded it and compiled the xcode-project copied the zfs.kext to /System/Library/Extensions, created a zpool and behold I had read/write access to my zfs disk.
Here are the easy steps (need xcode installed)
1. terminal: curl www.opensource.apple.com/darwinsource/tarballs/other/zfs-59.tar.gz | tar xzv
2. terminal: open zfs-59/zfs.xcodeproj
4. xcode: compile it (for Release)
3. terminal: sudo cp -R zfs-59/build/Release/zfs.kext /System/Library/Extensions
5. find a partition or disk or whatever. (I used an entire disk) (it will be destroyed) get the disk-info of it (command I on it in disk utility)
6. terminal: sudo zpool create name-of-pool disk (in my case: sudo zpool create test disk2)
Three things to remember!
1. It’s unstable. I got my first kernel panic after about 10 minutes. (perhaps updating the user-land utilities would help?)
2. Be cautious! zpool will NOT ask for confirmation before it „formats“ your disk, make sure you choose the right disk.
3. I don’t take any responsibility for this, use it at your own risk!
I haven’t played around with this much, it won’t auto-mount after a disconnect.
sudo zfs mount name-of-pool (mounts it if it’s ejected from finder)
taken from hsorbo’s blog