"Longhorn" will deliver major improvements in user productivity, important new capabilities for software developers, and significant advancements in security, deployment and reliability.

"Getting 'Longhorn' to customers in 2006 will provide important advances in performance, security and reliability, and will help accelerate the creation of exciting new applications by developers across the industry," said Bill Gates, chairman and chief software architect of Microsoft.

Microsoft will deliver a Windows storage subsystem, code-named "WinFS," after the "Longhorn" release. The new storage system provides advanced data organization and management capabilities and will be in beta testing when the "Longhorn" client becomes available.

At a meeting yesterday with several hundred of the company's top developer evangelists from around the world, Microsoft also announced that the Windows WinFX developer technologies, including the new presentation subsystem code-named "Avalon" and the new communication subsystem code-named "Indigo," will be made available for Microsoft® Windows XP and Windows Server 2003 in 2006. This availability will expand the scope of opportunity for developers by enabling them to write applications that can run on hundreds of millions of PCs, resulting in enhanced experiences for users of those operating systems.

"Avalon" is the graphics subsystem that will enable developers to build applications that provide breakthrough user experiences.

"Indigo" is a new approach to building and running connected systems built from the ground up around a Web services-oriented architecture. The advanced Web services support in "Indigo" will enable more secure, reliable and transacted messaging and greater interoperability.

Yesterday's announcements relate only to the "Longhorn" client operating system. Anticipated availability for the Windows "Longhorn" Server operating system continues to be 2007.