Jonathan Schwartz, CEO and president of Sun Microsystems, has taken away a bit of Apple's thunder by disclosing in advance of Apple's upcoming Worldwide Developers Conference that Apple will announce that Sun's open-source ZFS technology will become the file system in Leopard, the next version of the Mac operating system.

At a Sun event in Washington, D.C., Schwartz let the cat out of the bag while explaining Sun's strategy of releasing technology to the open-source community in order to seed the market for Sun services and hardware.

"In fact, this week you'll see that Apple is announcing at their Worldwide Developers Conference that ZFS has become the file system in Mac OS 10," Schwartz said. A video of Schwartz's speech is available online.

Introduced in May 2006, the 128-bit Zettabyte File System is part of Sun's commercial operating system Solaris and its OpenSolaris project. With a higher bit count than typical file systems, ZFS can create more unique addresses for storing data and files. Linux, Microsoft Windows Vista, and most Unix systems employ either 32-bit or 64-bit file systems, which are expected to meet the needs of even the largest computer systems for the next 10 years. With ZFS, Sun is thinking beyond the next decade.

ZFS would be an improvement over Apple's current file system HFS+, which was introduced in 1998 in Mac OS 8.0. HFS+ replaced Apple's Hierarchical File System, or HFS, as the primary system used in the Mac, and is also used in the iPod digital music player.

ZFS, available under the Common Development and Distribution License, was introduced by Sun in 2004. Unlike traditional file systems, ZFS has built-in data integrity and disk volume-management capabilities, instead of requiring its users to add on storage software that tries to overcome a file system's shortcomings.

Apple as a matter of company policy doesn't discuss upcoming announcements slated for its events. The company, however, is expected to discuss Leopard, or Mac OS X 10.5, and hand out beta versions to developers.