You've probably heard a lot about Windows Longhorn, the next version of Windows. This FAQ will attempt to answer common questions about Longhorn and give you a better understanding of exactly what this new operating system is about. This FAQ will continue to be updated and expanded as we near the Longhorn release.

"Longhorn" is the codename for a major wave of technology and platform software from Microsoft. This generation of software will include new versions of Windows, Windows Server, .NET, MSN, Microsoft Office, and other products. Windows "Longhorn" is the next major desktop Windows release, which will follow Windows XP; there is also a minor Windows Server revision that will ship in the Longhorn wave. Originally expected to be a fairly minor upgrade, Windows Longhorn will now include a number of new features including a revised task-based (or "iterative") user interface, an extensible, dock-like, Sidebar, and a SQL Server 2003-based storage engine called WinFS (Windows Future Storage). Microsoft said that Longhorn would be a desktop-only release in November, 2002, when the company told me that, "Customer requirements dictate our release strategies and timing for Windows products. Customers have asked that we map our server releases more closely to how they can consume and implement advances and innovations we deliver. Given the deployment cycles and budgeting that customers work through, and given the significant customer interest in our upcoming release of Windows Server 2003, we have determined that another major release of Windows Server in the Longhorn client timeframe does not meet the needs of most of our customers." However, those plans were up in the air until mid-2003, when the company revealed, finally, that it would indeed ship a Longhorn Server product as well.

Windows Longhorn is a major next-generation Windows version. Longhorn will feature improvements in how you store files, communicate, and work with digital media.

Yes. Like Windows XP, Windows Longhorn will ship in different editions, though they might change from today's Home, Professional, Tablet PC, Media Center, 64-Bit Professional (Itanium), Professional Edition x64, and Embedded Editions. For example, I'm expecting the capabilities of today's XP Media Center Edition to be incorporate into Home Edition or, perhaps, a high-end version for home that might be called Premium Edition.

Windows Longhorn will feature an entirely new interface known as Aero. The Aero interface will be powered by the new desktop composition engine known as Avalon. Avalon will allow for a dramatic improvement in the display of Windows, far surpassing that of Windows XP. In Longhorn, windows will animate onto the screen, feature drop-shadows, and allow for complete windows scaling (not just resizing). Other features such as full motion video overlays will also make Longhorn's user interface unlike anything seen before in Windows.

Here's what we know about Longhorn at this early stage:

• Longhorn will feature a task-based (or "iterative") interface that goes far beyond the task-based interface found today in Windows XP. Microsoft has been working to move beyond the dated desktop metaphor still used by most desktop operating systems; This new user interface, or "user experience," is code-named "Aero" and is based on a new .NET-based graphics API called "Avalon," which replaces earlier graphics APIs such as GDI and GDI+, the latter of which debuted in Windows XP.
• The Longhorn Start Menu and task bar will be enhanced with a new Sidebar component that can optionally appear locked to one side of the desktop. The Sidebar is an XML-based panel that includes links to local and remote resources.
• Longhorn will require 3D video hardware to render special effects that will make the screen more photorealistic and deep. This doesn't mean that the basic windows and mouse interface is being replaced, just that it will look a lot better.
• Longhorn will optionally include the Palladium security technology Microsoft is developing with Intel and AMD (see the next question for details).
• Longhorn will include new anti-virus (AV) APIs that will help developers more easily integrate their wares into the base OS. Microsoft will also offer Longhorn customers a subscription-based AV feature that use AutoUpdate to keep your system up-to-date with new virus signatures.
• Longhorn will include integrated recordable DVD capabilities and will work with every type of recordable DVD format. Digital media enthusiasts will be able to copy video from a digital camcorder directly to recordable DVD, bypassing the system's hard drive entirely, if desired.
• Longhorn will include an advanced version of the successful Error Reporting Tool (ERT) that shipped in Windows XP; the goal is that only a small number of customers should have to report a bug to Microsoft before the company fixes it and ships the fix electronically and automatically to users.
• Longhorn will include a new Setup routine that installs the OS in about 15 minutes.
• Longhorn will feature hundreds of new APIs that will let provide access to the new system's features. The Win32 API from previous Windows versions is being replaced by a new .NET-based API called WinFX, for example. It will also feature a new communications and collaboration subsystem, dubbed Indigo.

While Microsoft has performed public demonstrations of the current state of the new interface, they are currently keeping it under tight guard due to concerns of copying by competitors. Current alpha and beta version of Longhorn feature a temporary GUI, and the Aero interface will not be made public until Beta 2. Like in Windows XP's development, the Aero interface will not be completely finalized until Release Candidate 1 (RC1).

In the technology generations leading up to Longhorn, Microsoft has been moving to a .NET-based managed code environment dubbed WinFX, and the Longhorn generation will finally mark a clean split with the Win32 APIs of the past. That is, Win32 will be in maintenance mode, and all new development will occur with WinFX managed APIs. One such API, Avalon, forms the basis for the new Desktop Compositing Engine (DCE) in Longhorn that replaces GDI and GDI+. These and other new Longhorn APIs will utilize the XML Application markup language (XAML) to make Longhorn more accessible to developers than ever before. The idea is to significantly reduce the number of APIs and make the APIs more standardized. Today, there are over 76,000 Win32 APIs, and countless wrappers. With Longhorn, Microsoft hopes to reduce the API set to 8,000 to 10,000. Another significant change in Longhorn involves device drivers. In the past, Microsoft allowed customers to use non-signed drivers, which helped compatibility, but caused stability problems. No more: In Longhorn, users hoping to take advantage of the system's exciting new capabilities will only be able to use signed drivers.Developers interested in Longhorn should examine the Visual Studio 2005 "Whidbey" release, currently in beta, and the Longhorn SDK. which includes developer-accessible UI components and behaviors.

WinFS, an extension of the NTFS file system, is a new database driven file management system. Basically this means that in Longhorn, file searching will be much quicker and easier than before. Windows Longhorn will feature "libraries" that will locate and organize specific types of files on your computer. The My Music library, for example, will contain pointers to all the music files on your computer. You won't need to worry about exactly what file folder or folders your music is in. WinFS will essentially eliminate the need for less experienced computer users learn the idea of a file system.

One of the most exciting aspects of Longhorn is its optional integration with Palladium, Microsoft's technology for realizing its Trustworthy Computing vision. Palladium--now called Next Generation Secure Computing Base (NGSCB)--is basically a secure run-time environment for Windows and other operating systems that allows a coming generation of software applications and services to protect the end user from privacy invasion, outside hacking, spam, and other electronic attacks. Palladium requires special hardware security chips and microprocessors (which will be made by Intel and AMD) and doesn't interfere with the normal operation of the PC. That is, Palladium-based PCs will still operate normally, working with legacy operating systems and applications. But specially-made Palladium applications and services will offer a range of features of functionality not found in the non-Palladium world, and if the initiative is successful, we'll one day be running only Palladium-based software. If you're familiar with the .NET model, you might be aware of the notion of "managed" and "non-managed" (or legacy) code. Palladium will institute a similar model for PC software, where a trusted execution mode is used for Palladium applications and services and the old, "untrusted" mode is used for legacy code. Microsoft designed Palladium around the following ideals:

• Palladium will tell you who you're dealing with online, and what they're doing. It will uniquely identify you to your PC and can limit what arrives (and runs on) that computer. Information that comes in from the Internet will be verified before you can access it.
• Palladium protects information using encryption to seal data so that "snoops and thieves are thwarted." The system can maintain document integrity so that documents can't be altered without your knowledge.
• Palladium stops viruses and worms. The system won't run unauthorized programs, preventing viruses from trashing your system.
• Palladium stops spam. Spam will be stopped before it even hits your email inbox. Unsolicited mail that you might actually want to receive will be allowed through if it has credentials that meet your user-defined standards.
• Palladium safeguards privacy. In addition to the system's ability to seal data on your PC, Palladium can also seal data sent across the Internet using software agents that ensure the data reaches only the proper people. Newsweek reports that the agent has been nicknamed "My Man," a goof on ".NET My Services," "My Documents," and other similar names at Microsoft.
• Palladium controls information after it's sent from your PC. Using Digital Rights Management (DRM) technology, Palladium can be used to securely distribute music, movies, and other intellectual property securely over the Internet. Movie studios and the recording industry could use this technology to let their customers exercise their fair use rights to copy audio CDs and movies, for example. "It's a funny thing," says Bill Gates. "We came at this thinking about music, but then we realized that e-mail and documents were far more interesting domains." Gates says that Palladium could ensure that email designated as private could not be forwarded or copied to other people, for example. Or, the Newsweek reports reads, "you could create Word documents that could be read only in the next week. In all cases, it would be the user, not Microsoft, who sets these policies."

Late 2004. Microsoft recently provided developers with an early alpha build of Longhorn (4074) and the Longhorn SDK at the WinHEC conference in April 2004. I'm told the next public release will be Beta 1 in early 2005.

Microsoft has not yet detailed Longhorn's system requirements. However, in order to take full advantage of the new Longhorn interface, you will likely need at least a 3.0Ghz or equivalent with 1GB of RAM and a 128MB video card. Longhorn's interface, however, will scale back depending the capabilities of your computer. Therefore the bare requirements to run Longhorn will be lower than I just described. Nevertheless, these figures are only an educated guess and have yet to be confirmed or disproved by Microsoft.

While Longhorn's release date has been pushed back several times in the past, the current estimated release date is mid to late 2006.