Microsoft Group VP Allchin whipped through a lot of slides and information during his nearly two-hour keynote here at the Microsoft Professional Developers Conference on Monday. But by the end of his talk, we didn't learn much more than we already knew about the ETA for Longhorn, which is currently expected to go live in 2006.

Microsoft distributed a Longhorn developer preview release to show attendees, consisting of two CDs including 32-bit and 64-bit IA-64 and AMD-64 code. Attendees also received the Longhorn driver kit; Lohghorn software development kit, Visual Studio "Whidbey" PDC build; SQL Server "Yukon" PDC build and a version of Virtual PC 2004 which works with the Longhorn.

Don't expect to see the first true Longhorn beta until some time in the second half of 2004, however, Allchin told attendees. He refused to provide any further information on when Beta 2 or the final release might be ready.

He also warned attendees that they should expect to see "lots of warts" in the code they received today. "Performance is not good. You should put it only on high-end machines," Allchin said.

The PDC Build of Longhorn (Build No. 4051) does not include the Aero look-and-feel. It does not feature the migration utility that Microsoft is building to help its customers ugrade from older versions of Windows to newer ones in a more seamless and simple way. It also does not include WinFX, the set of managed application programming interfaces (APIs) that are designed to supersede Win32.

"If you have a Win32 app today, those apps should be able to run, barring security issues, on Longhorn," Allchin told keynote attendees.

"There are no WinFX APIs in the bits today," Allchin said. "But that should be very clear: that's the path we are on."

(Editor's note: The bulk of the WinFX APIs are, in fact,on the Longhorn Build 4051 that Microsoft distributed at the show.)

Also part of the Longhorn build as it stands today are three subsystems: the Avalon presentation, WinFS data and Indigo communications subsystems. (While Indigo is first and foremost about Web services, Microsoft recently folded its communications team into its Indigo team. As a result, Indigo refers now to not only the Web services bits, but also the P2P, instant voice and video chat, and other communications and networking bits that will be part of the product.)

Underneath these subsystems rests a layer to which Microsoft refers as "fundamentals." These are the core Windows technologies that Microsoft is designing to support security (via the Next Generation Computing Base subsystem), more reliable drivers, fewer reboots, etc. (Allchin's promise to reduce reboots elicited the loudest round of applause of any of the demonstrations during his keynote.)

But back to the new subsystems…

Avalon includes two parts: a hardware interface component and a programmable front end.

"Today, there's Windows apps and Web apps," Allchin told the keynote attendees. "We think people want one world. And we think we're on path to solve these problems."

Avalon is the new single programming model that will provide a unified presentation model for Windows apps, Web apps and "media-type apps," Allchin explained. On the back end, Avalon replaces the User and GDI graphic subsystems.

On the front end, Microsoft is providing support for a new markup language called XAML that "lets you build a Windows application in a declarative way." Allchin said XAML will make applications easier to learn, write and read because it allows developers to separate code and content. XAML sounds like a rival to XUL, but no Microsoft officials have made that comparison publicly so far.

On the storage front, Microsoft is betting on WinFS to help it solve a number of storage challenges it currently faces. Data is currently trapped inside separate application siles, each with its own schema and store. Relationships between people and objects tend to be buried because software today doesn't surface the obvious links and doesn't include very good semantic knowledge.

To fix these shortcomings, Microsoft is adding extensible XML schemas, logical views, programmatic relationships, synchronization service and information agents. It also is rolling out WinFS, a data store grounded in its SQL Server Yukon technology, which sits on top of the existing Windows NTFS file system. Developers can opt to make use of the WinFS store, or not, Allchin said.

And on the communications front, Microsoft is lumping everything from P2P to Web services under the "Indigo" subsystem.

"Indigo is a subsystem that does everything for you," Allchin said. It provides reliable message transaction, heterogeneous interoperability, messaging capabilities and a simpler way to build and consume Web services. If you remember "Hailstorm," Microsoft's personal Web services technologies, a number of them are set to manifest in Indigo.

Allchin mentioned a couple of other technologies in his remarks which we're still working to flesh out.

ClickOnce, a new application installation technology that ultimately will be part of Longhorn, is basically a successor to the current Windows Installer technology. And if you've heard rumors about Microsoft including new licensing technology in Longhorn in Longhorn, it's going to be some kind of "automated facility for licensing technology" for third-party software products. That's all we know on it, for now.

There's more to come from the PDC all week. Stayed tuned for more details.