LAS VEGAS--As Microsoft works to woo Web developers to its tools, it is subtly trying to wean them from one product that the company once touted as the answer to advanced graphics development: Silverlight.

The first day of Microsoft's Mix11 conference here, the company's annual gathering of Web developers, included demonstrations and talk about HTML5, the emerging Web standard. HTML5's promise is to make developing Web applications that use video and animation easy, much the same thing for which Microsoft created Silverlight.

But Silverlight was largely missing in action today. The technology was never mentioned in either of the keynote speeches by Dean Hachamovitch, corporate vice president of Internet Explorer, and Scott Guthrie, corporate vice president of Microsoft's .NET Developer Platform.

In debuting a preview version of Internet Explorer 10, Hachamovitch played up its support for HTML5, demonstrating smooth graphics programs loading quickly from the Web, like the new multi-level Pac-Man application, built by Namco for the 30th anniversary of the game.

Namco&39's Pac-Man

Microsoft has been de-emphasizing Silverlight for several months now. As veteran Microsoft watcher Mary Jo Foley noted at the company's Professional Developers Conference in October, Silverlight started falling off the radar. Just last week, Microsoft played up Silverlight's role as a browser plug-in, which, in turn, demoted its role as the key platform for advanced Web graphics.

The reason, according to Tim O'Brien, a general manager in Microsoft's platform strategy group, is that HTML5 has evolved and addresses many of the technical issues that are core to Silverlight.

"The things that are driving this shift are the market dynamics," O'Brien said. As the standard evolves, it becomes easier for developers to create applications for it. And writing for the standard means that the application will run more widely than writing for a plug-in such as Silverlight.

Silverlight still has its place, O'Brien said. It offers support for digital rights management, and handles Smooth Streaming, which speeds video start times. "There is no single answer for all programming tasks," O'Brien said. And tomorrow at Mix11, Microsoft plans to roll out the beta version of Silverlight 5.

But it also seems clear that Microsoft is placing an ever-larger bet on HTML5. The company disclosed that its next Professional Developers Conference will be September 13-16 in Anaheim, Calif. For Microsoft, the PDC is a stake-in-the-ground event where the company lays out a broad vision for its vast developer community to follow. The September PDC will likely be the place where the company shares details for its upcoming Windows 8 operating system. Expect HTML5 to be play a role there as well. "We're going to place more emphasis on HTML5," O'Brien said.