Sun Microsystems has published specifications for its UltraSPARC T1 processor, open sourcing its latest chip, while issuing a challenge to IBM and Intel.

Sun on Tuesday released the specifications for the UltraSPARC processor architecture 2005 and its HyperVisor API under the General Public License (GPL) 2.0. The architecture is available at www.opensparc.net.

Open sourcing the architecture, an idea first announced by Sun chief executive Scott McNealy in December, is designed to make Sun's platform a popular choice for ISVs, developers and enterprises using Linux and BSD operating systems and applications. Sun is hoping the T1 performance gains and low-power consumption will appeal to start-ups and companies who'd otherwise build web farms using Linux on Intel's Xeon.

In particular, companies in India, China and Japan might look to pick up Sun's chip design. With eight processing cores, the UltraSPARC T1 stands as a unique product and could be used to create security or networking appliances.

Sun's move to free its hypervisor API is a bid to reach closer to the open source Xen hypervisor. Sun hopes that companies will start tuning Linux and BSD for its chip. This, however, will require tons of work, and it's unlikely that Sun's hypervisor layer will be merged with Xen in the near future.

Sun president and chief operating officer Jonathan Schwartz, speaking at the Open Source Business Conference (OSBC) in San Francisco, called publication of the UltraSPARC architecture a "huge change." "I'd love to have... fabs all around the world fabbing SPARC. It's a huge opportunity for us."

In a nod to IBM and Intel, who have backed open source software and initiatives but so-far shied from open sourcing their chip specs, Schwartz said: "We'd love to see other hardware companies follow in our footsteps.

"This is an inexorable shift in the marketplace. Open source is not just about software. It's also about hardware," Schwartz said. "You can't create a community without contributions. You can't write press releases to say you like open source. If you like open source, wade on in and make contributions."

Intel and IBM, of course, have the dominate chip architectures of the moment and are less inclined to free up their hardware. IBM, however, does let customers tweak its Power designs on a limited basis

Sun chose to release UltraSPARC under GPL because it owns all of the intellectual property (IP) contained in the chip, the ponytailed prez said. The company landed in a bit of hot water last year for releasing Solaris 10 under its own Common Development and Distribution License (CDDL) instead of the GPL.

"We don't own 100 per cent of the IP in Solaris. This is a different platform. We own 100 per cent of the IP that goes into it. We can faithfully deliver it into the free marketplace under a license that promotes freedom and choice," Schwartz said.®