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

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 also announced on Friday, as expected, that just as it has done with the Longhorn communications subsystem (code-named "Indigo), it will make the Longhorn "Avalon" graphics subsystem available for Windows XP and Windows Server 2003. Microsoft officials said they expect to deliver the Avalon and Indigo versions for older Windows platforms in 2006, right around the time that Longhorn ships.
Longhorn is still slated to include both the Indigo and Avalon subsystems, contrary to some rumors circulating over the past couple of days. And Microsoft is still expecting to deliver as part of Longhorn updated "fundamental" APIs providing core power management, driver management, application installation/deployment, digital rights management and other basic tasks.
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.