Sun Microsystems CEO Jonathan Schwartz has gone on record to claim that Apple will use his firm's ZFS file system within Mac OS X 10.5 'Leopard'.

Speaking at a company event, Schwartz claimed that Apple plans to adopt ZFS as the default file system in the future Mac OS, replacing its current HFS+ Extended system.

"This week, you'll see that Apple is announcing at their Worldwide Developers Conference that ZFS has become the file system in Mac OS X," Schwartz said.

Marc Hamilton, Sun's director of technology for global education and research added: "Jonathan noted that Apple will announce this week that the ZFS file system from OpenSolaris will become Apple's new default file system.”

If true, Apple's move confirms a year-old rumour. In May 2006 an email message purported to come from Sun's Eric Kustarz claimed: "Here's some exciting news! Chris Emura, the filesystem development manager within Apple's CoreOS organisation is interested in porting Solaris ZFS to OS X."

The rumour flew once again last December when a French-language Mac website claimed the latest builds of Mac OS X 10.5 offer support for the file system, including permitting the creation of ZFS-formatted disk images or partitions.

ZFS is an incredibly advanced 128-bit file system - it's capable of storing a huge amount more data than a 64-bit system - 16 billion billion times the capacity of 64- or 32-bit systems. That's essentially unlimited by today's standards.

ZFS also manages to create system snapshots on the go, potentially of use in Time Machine. It also performs better than previous file systems as it works so very differently.

The system is designed along a principle of storing elements of what filesystems need in one pooled storage area, which can be accessed on the fly. This means only those elements of ZFS that are required at any one time are actually used, which helps boost system performance.

Sun also claims the system doesn't require the running of certain system administration tasks, and doesn't ever lose data following a system crash. It's also self-healing.

You can watch Sun's boss making his claims in this video.