Microsoft Corp. is integrating the .Net framework into its new Silverlight browser technology for running multimedia applications on the Web, the company revealed Monday. The move is part of an expanded effort to build a significant developer base so Microsoft can catch up to Adobe Systems Inc. in providing a revenue-generating business in the rich Internet applications (RIAs) market.

Chief Software Architect and CTO Ray Ozzie made the announcement in a keynote speech to kick off the MIX 07 conference in Las Vegas. He said Microsoft is shipping a cross-platform version of the .Net framework for the browser in Silverlight, which went into its first beta Monday.

Both the Silverlight 1.0 Beta and Silverlight 1.1 Alpha are immediately available for download at http://www.microsoft.com/silverlight.

Silverlight, unveiled a few weeks ago, is essentially a cross-browser, Web-based version of Microsoft's Windows Presentation Foundation (WPF), the user-interface framework in Windows Vista. Silverlight is a cross-platform delivery mechanism that competes with Adobe's Flash player, which is an enormously popular way for developers to add multimedia content to Web sites.

Microsoft is encouraging developers to build applications for it through both the Microsoft Expression toolset and Microsoft Visual Studio integrated development environment (IDE). In fact, the company Monday updated the currently available alpha of the next version of Visual Studio, code-named Orcas, by adding Silverlight to it in an offering called Silverlight Tools for Visual Studio "Orcas."

Microsoft hosted its first MIX show last year as an appeal to Web designers and developers of RIAs, an audience whose respect the company has yet to win. Microsoft has made several stops and starts in offering Web authoring and design tools over the years, but has always had far better success with client-side developers. Leveraging .NET developer community to build application for Silverlight is a clever strategic move for the company so it can gain ground its lost to Adobe and others by its long-time reluctance to accept the Web as a development platform.

Ozzie also Monday unveiled a Silverlight companion technology, Microsoft Silverlight Streaming by Windows Live, a hosting and repository service that lets Web designers and developers stream cross-platform, cross-browser RIAs on both Windows and the Apple Macintosh OSes. The company also said it opened up APIs to Windows Live services through new licensing terms so they can be integrated intro the Silverlight Streaming service and delivered on Silverlight applications.

The IDG News Service is a Network World affiliate.