News

Longhorn Packed with Changes

• By Scott Bekker
• 10/30/2003

Delivery is somewhere between two and three years away, and the development process hasn’t reached the alpha testing stage, so Microsoft isn’t even close to finalizing the feature set. Nonetheless, the company is confident enough about the broad strokes to start encouraging the developer community to start thinking about writing applications for the operating system. Longhorn’s major themes are strengthening operating system fundamentals, overhauling the presentation layer, building in radical enhancements to the file system and embracing Web services in internal and external communications.

A widely circulated chart at the PDC lays out these pillars in large blocks with their associated code-names. Fundamentals, a.k.a. Base OS Services, lies at the bottom of the chart, supporting all the other enhancements. Resting on top of Fundamentals are three equal-size blocks: “Avalon” for the presentation layer, “WinFS” for storage and “Indigo” for communication. Atop the whole structure is WinFX, which Microsoft group vice president Jim Allchin describes as “the step beyond Win32” programming.

Microsoft chairman and chief software architect Bill Gates said this week that Longhorn will be Microsoft’s biggest launch since Windows 95. Whether or not that proves true in terms of market excitement, it looks like it may be true in terms of the amount of new code and features. On the client side, Windows 2000 to Windows XP represented a small jump in terms of size of the code-base, and the same was true for the server-side move from Windows 2000 to Windows Server 2003. Longhorn, on the other hand, promises to be a big jump – perhaps on the order of Windows NT 4.0 to Windows 2000.

Strengthening OS Fundamentals

Fundamentals aren’t the most exciting elements, but a lot of significant work is going into the base OS for Longhorn. Allchin, who provided reams of technical detail in a long presentation this week, said changes to the OS fundamentals are organized into security, deployment and performance.

The biggest security change was one of the earliest elements of Longhorn to surface. Known originally as “Palladium” and later as the Next Generation Secure Computing Base (NGSCB), it will consist of a piece of code called a nexus that will authenticate against next-generation hardware to hide segments of memory and authoritatively identify a system to other applications, among other changes.

But Microsoft had some announcements around Longhorn security at PDC, as well. The company will build into Longhorn some of the standards body work it contributed to in WS-Security (WS stands for Web Services). Additionally, the operating system will support the no-execute capability that is being built into newer hardware. For the record, Microsoft is planning to support no-execute flags in Windows XP Service Pack 2, as well.

In deployment, Microsoft will introduce something called ClickOnce technology to developers in Visual Studio “Whidbey” and to users in Longhorn. ClickOnce will abstract a complex installation process for developers, and will make application installs and uninstalls a quicker, one-click operation for users, according to Microsoft.

The operating system will also add Servicing APIs to reduce the need for reboots when applications install. The new APIs will give developers a way to alert applications to shut down in part to integrate new capabilities without a reboot.

Finally, in deployment, Microsoft plans to aggressively reduce the time it takes to migrate from one computer to another or to upgrade from one operating system to another. Said Allchin: “Today it’s a weekend of work if you’re at home. … We’re going to get it down to where it’s in the minutes range.”

The hint that Longhorn will contain a massive amount of new code came when Allchin was discussing performance improvements, especially a paging feature called Super Fetch. The technology is supposed to make the system smarter at predicting what data will need to be called again in the future. But it won’t actually lead to improved performance over today’s levels.

“We’re adding a lot of code in Longhorn, and we’re going to be able to hold [the] performance … we’ve got today by the fact that we’ll have the capabilities such as Super Fetch,” Allchin said.

Other performance enhancers in the fundamentals category include Glitch Free technology for managing media streams, better driver verification and a flight data recorder technology that is supposed to help trace problems with applications and the operating system.

Overhauling the Presentation Layer

Many of the rumors surrounding Longhorn involved the user interface, and much of Microsoft’s focus in the early Longhorn development work relates to the UI. Officially, Avalon is described as a declarative, vector-based, compositing UI.

In practice, Avalon will give developers a number of new hooks to create attractive and usable UIs for Windows applications.

For one thing, Microsoft is aiming for a more unified presentation between traditional Windows applications and traditional Web applications. “We’re going to take the best of both worlds and create one programming model that you can count on,” Allchin said. Examples of having the best of both worlds could include being able to access Web applications from the “Start” button, being able to access Windows applications from the IE Favorites menu and having some offline capabilities for Web applications.

Avalon’s vector-based compositioning engine will combine the two existing families of video hardware drivers – 2-D and 3-D. “You get better performance because you don’t have to switch between the pipelines, between the 2-D and the 3-D,” Allchin said. The new vector approach, meanwhile, is supposed to improve graphical performance.

New native APIs will be added to Avalon for speech, remote-control and digital-ink input, to reduce coding time and improve performance.

Microsoft is also adding a new markup language, called XAML, for building Windows applications. The new approach is supposed to make it possible for development teams to separate the coding from the content of an application, allowing different members of the team to focus on their core skills.

Relatively little was revealed at the PDC of ”Aero,” the radical overhaul of the user interface that Microsoft is working on for Longhorn. A Developers Preview of Longhorn handed out to conference attendees does not include Aero. But Microsoft did demonstrate one user interface change called the Sidebar, which appears off to the side of the desktop and can be used by developers to display various information from their applications.

Radical Enhancements to the File System

The Windows Future Storage or WinFS file system is one of the highlights of the upcoming operating system. Gates admitted he’s been trying to get a new file system for Windows for years. “Some of you here have heard me talk about unified storage for more than a decade,” Gates said during his keynote. “The idea of taking XML flexibility, database technology, getting it into the file system; that’s been a Holy Grail for me for quite some time.”

At this point, it appears that it may finally happen. Microsoft was able to demonstrate WinFS at the PDC. Using the WinFS, users will be able to dynamically change views of the data stored on their systems. By schematizing data, files can be rearranged and collected by different criteria. Using WinFS will also allow data to be moved around between devices without users needing to perform conversions.

Embracing Web Services in Communications

Windows XP shipped too soon to include the .NET Framework for Web services. Windows Server 2003 did get the framework included, but Microsoft says that Longhorn is the first operating system with major new features based on Web services.

Microsoft describes Indigo as the next link in the COM, COM+, .NET Framework chain. At its core, Indigo is a unified programming model and communications infrastructure for developing connected systems. Indigo will be available as a download for Windows XP and Windows Server 2003, but certain features of Indigo will only be available to Longhorn-based systems.