As expected, Microsoft on Monday released a Community Technology Preview of WPF/E, the company's so-called "Flash killer." But perhaps more important than the implication for Flash is Microsoft's contention that the difference between Windows and the Web is disappearing.

Specifically, WPF/E is a subset of the Windows Presentation Foundation that utilizes cross-browser Web technologies and is designed to run on multiple operating systems and even mobile devices. Like Flash, WPF/E works as a browser plug-in and can display vector-based graphics, animation and video.

WPF/E was introduced at PDC 2005 and further showcased at Microsoft's MIX '06 event in Las Vegas earlier this year. It relies on XAML and JavaScript to build pages, and also contains a small, cross platform subset of the CLR and .NET Framework that runs C# or VB.NET code.

Microsoft's recently introduced Expression Studio tools fully support WPF/E; XAML code can be developed by Expression Blend and Design, and Design can export interfaces directly into WPF/E. The idea is that developers can use the same tools to build applications for both the desktop and the Web, even utilizing the same interfaces.

"Web and Windows is a deliniating mark that doesn't really exist anymore," Forest Key, Director of Web and Client UX Platform Marketing for Microsoft's developer division, explained to BetaNews. Such a statement is surprising coming from a company that has fought fiercely to protect its software sales in the face of an emerging Web-centric application industry pioneered by the likes of Google.

Unlike full-fledged Windows Vista applications, however, WPF/E is lightweight, which is why it was named as such: Windows Presentation Foundation/Everywhere (although, Microsoft says it will rename the product for the final launch). The Active X plug-in for Internet Explorer is only 1.1 megabytes.

Moreover, WPF/E is completely cross platform. The final release, due in the first half of 2007, will run on both Windows and the Mac, with support for IE, Firefox and even Apple's Safari Web browsers. In the second half of next year, Microsoft will add support for the .NET Compact Framework, meaning WPF/E will run on mobile devices as well.

While the comparisons to Flash are obvious, Microsoft's Key cites a big difference for developers: a WPF/E application is "not a compiled binary that is delivered down to a Flash player." Instead, all of the code is standards based and the graphics make use of XAML.

Still, Adobe is likely to be on edge after Monday's announcement. WPF/E is encroaching on territory long held by Flash on the Web, and like Microsoft, Adobe is also endeavoring to embed Flash into mobile devices such as cell phones.

Perhaps most interesting about WPF/E is Microsoft's push to reinvigorate Windows Media Video as a major distribution format over the Web. Although WMV can now be found on DVD players and the WMV-based VC1 codec is part of both HD DVD and Blu-ray, Flash video has slipped in the back door and beaten both Microsoft and RealNetworks when it comes to video on the Web thanks to sites like YouTube and Google Video.

Microsoft is hoping to change that with WPF/E. The plug-in will natively support playing back WMV clips, and a new tool -- Expression Media Encoder -- will make publishing video for the Web simple and quick. With Windows Media Player for the Mac abandoned, WPF/E will also replace Flip4Mac as the primary way for Mac users to view Windows Media on the Web, Key said.

"What makes WPF/E really nice from a developer perspective is that it is easy to integrate it within existing HTML pages and sites. Developers can write standard JavaScript within an HTML page to directly manipulate and program against any XAML DOM element, storyline animation, or video within WPF/E," explained Microsoft developer Scott Guthrie.

"This enables developers to easily add WPF/E assets to their existing AJAX-enabled HTML solutions today, and be able to use a single code-base with a consistent AJAX framework to work against both the HTML and XAML DOMs on the page at the same time."

But a grandiose vision doesn't necessarily translate into success, and Microsoft knows it has a long way to go to bring developers on board. The company is planning to hold its second-annual MIX conference in Las Vegas this spring, which will serve to convince programmers and application designers to adopt its next-generation tools.