I happen to know someone that works for Sun and he gave me some extra info on the ZFS thing in Leopard, not that i understand everything he said but it was interesting non the less. - ZFS can't boot a system because it doesn't work with the open firmware bootsystem from Apple and Sun that uses something similar, it only works with EFI but that technology isn't made available yet by Sun. I don't think it will work on the 'old' PPC architecture that doesn't support EFI, so it won't be the standard filesystem until osX is Intel only. I'l guess we'll have to wait for osX 10.6 'Racoon' for that. The SCO statement about ZFS and osX may be true but in this stage clearly no more than a publicity stunt for Sun. - ZFS has 3 layers, don't ask me about the other 2 but the second layer is a fully usable object oriented database. The apps and the user itself can directly access this database to store/retrieve information as objects. This will no less than revolutionize the way the OS works and databases in general, i don't see it happening in Leopard just yet but 10.6 will again be a leap forward just because of the ZFS aware apps and OS.