It's a sad day for UNIX fans as the world's one-time leading proponent of the venerable operating system has announced a deal with Microsoft to resell Windows Server on its machines. Of course, that's not how Sun is positioning this news: The company says it has "expanded its strategic alliance" with Microsoft, an alliance that apparently started when the two companies settled their antitrust spat back in 2004. As part of that settlement, Microsoft paid Sun a one-time fee of almost $2 billion.

"Sun is now a single source for today's leading operating systems--Solaris and Windows--on the industry's most innovative x64 systems and storage products," says Sun executive vice president John Fowler, neatly avoiding use of the word 'Linux.' "Customers can now take advantage of the virtualization benefits of Windows and Solaris on Sun's energy-efficient x64 systems. Microsoft's recognition of our x64 systems and storage is a testament to the superior system design at the heart of our product portfolio."

Aside from an apparent inside joke involving the number of times Fowler could work the term 'x64' into his press release quote, the Sun/Microsoft announcement yesterday essentially formalizes the process by which its customer can install Windows Server on Sun's industry-standard servers. So-called x64 systems are those with 64-bit processors made by Intel or AMD. Sun sells this type of machine in addition to those based on its own SPARC processor line.

Currently, Sun is the number three server maker worldwide behind IBM and HP, both of which already sell a mix of UNIX/Linux and Windows-based servers. Sun's new Windows-based servers will run Windows Server 2003, the company says, and be made available to customers within 90 days.