In a conference call unveiling the agreement, Schwartz notes that IBM Big Blue is the first tier-one vendor partner for Solaris, although Dell has said that it might support Solaris one day and HP already does on an arm's-length basis.

"We are not trying to force the client into one operating system or the other," said Bill Zeitler, vice president of the Systems and Technology Group at IBM. "If Solaris has characteristics that you like, we would like you to consider our hardware platform."

"Does this change the world?" Schwartz asks himself in his industry-leading blog. "Answering for Sun, I think yes - it does." He then explains how:

"The announcement validates what we've been saying all along - the momentum around Solaris as a cross platform, open source operating system is indisputable. Driven by integrated virtualization, extreme performance, the integrity of the open source OpenSolaris community, and most of all... driven by tons of new developers and customers, across the world, building new solutions and businesses on the web."

The agreement is an extension of IBM's existing support for the Solaris OS on select IBM BladeCenter servers. The Solaris OS is supported on more than 820 x86 platforms and runs more than 3,000 unique x86 applications including IBM Websphere, Lotus, DB2, Rational and Tivoli.

"By adding the Solaris OS to its operating system portfolio, IBM is expanding customer choice," said IBM in an announcement. "And by participating as one of over 800 partners in the IBM BladeCenter ecosystem, Sun has effectively joined others in the industry helping IBM accelerate the development and adoption of open blade server platforms."

"Vendors that don't offer choice can only serve customers that don't want choice," Schwartz told a journalist, pointedly. "While IBM and Sun can serve the rest."

He makes a good point.

• IBM, Sun's Hereditary Enemy, Is Going to Sell Solaris