By Michael Cherry [bio]
Posted: May 9, 2005

• Illustration: Windows Major-Minor Release Cycle
• Illustration: Near-Term Windows Releases

The following is the full text of an article published by Directions on Microsoft, an independent research firm focused exclusively on Microsoft strategy & technology. Each month we make one or more key articles available to non-subscribers.

Allchin Restarts Longhorn Wave

With the release of Windows Server 2003 SP1 and editions of Windows for the AMD and Intel x64 processors, the Windows team has returned its main development focus to Longhorn.

As a prelude to the Apr. 2005 Windows Hardware Engineering Conference (WinHEC), Platforms Group Vice President Jim Allchin signaled that Longhorn is once again becoming the main priority on the Windows roadmap by introducing the "Third Decade of Windows." Allchin used his presentation to outline broad goals for Longhorn, including providing unrivaled security and safety, improving users' ability to visualize and organize information, reducing operational costs, being the "mobile OS," and providing operational simplicity through greater intelligence and consistency. However, Allchin provided few details on how Longhorn would accomplish these lofty goals.

Allchin's roadmap for shipping Longhorn was as vague as the feature details, but Microsoft told OEMs and hardware developers at WinHEC that the main hardware-dependent features have been fixed. These partners received a preliminary build of Longhorn with the components they need for developing device drivers, although the UI and shell for this release will have little resemblance to the final product. IT professionals will get a beta with the "foundation capabilities" (likely the "Avalon" graphics engine and "Indigo" Web services capabilities, but without the final UI and shell that will run on these components) in the summer of 2005. At the Professional Developers Conference (PDC) in Sept. 2005, developers will receive a more complete Longhorn release to help them determine how they will have to change their applications to exploit Longhorn.

The first real look at the final feature set will likely come during 2006 when end-users get a crack at wider, public betas. Allchin indicated that the final version of the product will be broadly available by "holiday 2006" (another vague calendar reference presumably referring to the Thanksgiving through New Year's Day holidays in the United States), a date range that, with any further slips, will push the product into 2007.

Allchin also committed both the Windows server and client teams to a predictable release cycle of alternating major and minor releases. A major release will include changes to the underlying core components such as the kernel; a minor release will tweak existing features, such as turning on the Windows Firewall, or add new higher-level features, such as a Security Configuration Wizard. (For an illustration of this cycle, see"Windows Major-Minor Release Cycle".)

The Rough Road to Longhorn

Microsoft initially announced Longhorn at a PDC in Sept. 2003. At that time, Microsoft executives were heralding a wave of products built on a major reworking of the Windows code that would feature a new graphics system, messaging technology, and file system, among many other improvements. However, this ambitious plan has run into some harsh realities.

Interruptions and Additions

Several shorter-term concerns have affected the plan for Longhorn, leading to a large grouping of releases in 2005 and 2006. (See the illustration"Near-Term Windows Releases".)

Security. Dramatic growth in security threats aimed at Windows has forced Microsoft to devote much of its Windows development and test resources to hardening the security of Windows XP with what amounted to an interim release (SP2). The company also raised the bar for future versions of Windows, requiring that they meet the high security thresholds stipulated by the Trustworthy Computing initiative. In addition, a more secure version (7.0) of Internet Explorer will be made available for Windows XP SP2 prior to Longhorn.

More editions. In an effort to gain a higher profile in high-performance computing (HPC), a niche market that generates little revenue but considerable bragging rights, the company also announced Windows Server 2003 Compute Cluster Edition, a product for running clusters of low-cost servers that work in parallel to solve complex tasks.

New processor architectures. AMD's extended 64-bit architecture (x64), which runs existing 32-bit applications without the performance compromises of Intel's Itanium, has had unexpected success. When Intel decided to adopt the x64 architecture for some of its own processors, yet another task was added: x64 versions of the Windows client and Windows Server.

Back-porting Longhorn features. To get better adoption by application developers, Microsoft has decided to provide versions of Longhorn's Avalon (graphics) and Indigo (Web services) features for current Windows client and server editions.

Microsoft has ruled out one additional task, a fifth service pack for Windows 2000 Professional and Server, but that change does little to relieve the workload: the security Update Rollup that replaced Windows 2000 SP5 will still involve significant development and testing resources, despite the fact that most work on service packs and rollups is done by the Windows Sustained Engineering team (which does not develop new versions of Windows).

These requirements had to compete for Windows development time not only with Longhorn but also with products that were always on the Windows roadmap, notably Windows Server 2003 SP1. In particular, all of these development projects compete for time in build and test labs, and for the time of developers and testers on shared teams such as the Windows Core and Networking groups.

Microsoft says that the four main groups that work on Windows—the Core, Client, Server and Sustained Engineering teams—work independently without blocking dependencies, and therefore will have no trouble delivering all of the scheduled 2005 and 2006 releases. But the reality is that Sustained Engineering cannot solve every security and functionality bug without having to check aspects of the bug with the original developer, and some changed code for bug fixes and services packs must be integrated back into the main code base. This is evidenced by the Windows XP SP2 changes, all of which were incorporated into Windows Server 2003 SP1.

Something's Gotta Give

Microsoft says it will ship Longhorn in 2006, but in order to meet this schedule, the company may have to postpone some Longhorn features to later releases, as has been done with the Windows File System (WinFS) and the Next-Generation Secure Computing Base (NGSCB) for digital rights management. Alternatively, Microsoft could reduce the number of Longhorn previews and betas to relieve pressure on build and test processes, but this would limit the feedback from developers, IT, and end users, and therefore negatively affect the overall quality and customer acceptance.

Finally, to ensure Longhorn ships in 2006, Microsoft could let shipment dates slip for less-critical products, such as the Compute Cluster Edition. The first Compute Cluster SDK was distributed to select ISVs and OEMs in late 2004, and Microsoft will refresh that SDK this summer. However, the full Compute Cluster Edition itself will not appear as a beta until the second half of 2005, and the final release is now scheduled for the first half of 2006—six months later than planned. (Microsoft insists it did not delay the Compute Cluster Edition because of schedule conflicts, but rather to incorporate feedback from beta testers; in particular, the company says customers have asked for improvements in how the Compute Cluster Edition is deployed and managed.) A delay in shipping the Compute Cluster Edition might cost Microsoft some market share against HPC clusters running Linux on low-cost computer hardware. However, it is probably better for Microsoft to delay release of a product targeted at a niche market than to delay products that affect far more customers, such as Longhorn, Windows Server R2, or the Windows Server Update Service.

Resources

The Longhorn components that will be available on existing versions of Windows and the delay of WinFS are described in "Longhorn Components on Windows Roadmap" on page 3 of the Oct. 2004 Update.

The high-performance features of Windows Server 2003 Compute Cluster Edition are described in "Windows for High Performance Clusters on Tap," on page 6 of the Aug. 2004 Update.

Information on the Windows Server 2003 Compute Cluster Edition is available at www.microsoft.com/windowsserver2003/hpc/default.mspx.

The Mar. 2005 Enterprise Software Roadmap provides an all-in-one planning reference with estimated release dates for future products, release histories for past versions, product overviews and new feature summaries, code names, support deadlines, retirement dates, and product dependencies for more than 100 versions of Microsoft enterprise software products.