Microsoft is cutting back its Longhorn client's planned feature set so as to be able to make its current delivery targets: Beta 1 by next year and final release some time in 2006.

Microsoft officially confirmed what had been leaked by developer sources late on Friday: changes to its future roadmap for the desktop version of Longhorn. And while developers and customers who expected they'd be required to rewrite their applications to take advantage of Longhorn may be happy with Microsoft's roadmap changes, others who were banking on promised Longhorn features, such as the next-generation Windows File System, will be far less so.

The Windows File System (WinFS)—technology that was set to simplify information storage and retrieval—won't make it into the final, shipping versions of Longhorn client, company officials said. WinFS also won't be part of Longhorn server, the server complement of Longhorn that is still due out in 2007, as Microsoft announced earlier this year.

Click here to read more about Microsoft's official line on Longhorn's future.

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The end result? Longhorn is going to be a lot more of an evolutionary than a revolutionary Windows release.

"Longhorn is going to stop being a whole new thing and more of an XP with a lot of good new stuff," said one developer close to Microsoft, who requested anonymity.

Microsoft officials declined to comment on the pending announcement, other than to say it will happen on Friday and will involve Longhorn.

As outlined at the Microsoft Professional Developer Conference (PDC) in the fall of 2003, Longhorn was to be comprised of four key pillars: The Windows File System, or WinFS; the Avalon presentation subsystem; the Indigo communications subsystem; and the "Fundamentals" pillar, consisting of APIs designed to provide core power management, driver management, application installation/deployment, digital rights management and other basic tasks. These pillars were designed to plug into a new programming model designed to replace Win32, known as WinFX.

Microsoft distributed to PDC attendees a pre-alpha version of Longhorn that included rudimentary versions of most of these subsystems. A true alpha release had been expected this fall.

Click here for an eWEEK Labs review of the latest Longhorn build.

But Microsoft has decided its initial set of Longhorn features was too ambitious, sources said. Executives are chopping away at the planned feature set. The resulting Longhorn is expected to consist primarily of incremental, core improvements—better performance, power management and the like.

Since this spring, Microsoft has been trimming the technologies it hoped to include in each pillar. But officials have insisted that the cuts were fairly limited and would not result in many changes to the Longhorn code that it has been distributing to developers since 2003.

On Friday, however, Microsoft is expected to admit that in order to get Longhorn out the door, the Windows team needs to take more far-reaching measures, developer sources said.

Click here to read the full story at Microsoft Watch.

Editor's Note: This story was updated to include information from an interview with Microsoft officials.

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