Microsoft plotting to steal Adobe's thunder

Microsoft is today expected to launch a web browser plug-in - called Silverlight - for playing media files and displaying interactive web applications at the National Association of Broadcasters (NAB) Show in Las Vegas.

The company intends to release a beta of Silverlight, formerly called Windows Presentation Foundation/Everywhere (WPF/E), at the Mix07 conference for designers and web developers in Las Vegas later this month.

Along with the public launch of Silverlight, Microsoft is planning to name a number of media and advertising agency partners that have shown interest in using the software. Partners include Akamai Technologies, online video broadcaster Brightcove, Major League Baseball and Netflix.

Silverlight, which has been under development for at least two years, is a player that can display web applications on both Windows and the Mac in Firefox, Internet Explorer or Safari. The download of the player will be less than 2MB.

Like Flash, it has accompanying development tools for both designers and software developers.

By launching Silverlight at the NAB conference, Microsoft is trying to spark the interest of media companies moving online. The company's Windows Media Video format is widely used, particularly for downloads. But Adobe's Flash Player has become the dominant choice for streaming video used by high-volume sites such as MySpace.com and YouTube.

Brightcove, for example, displays all of its video using Flash but the company intends to support Silverlight as an output format later this year to appeal to customers who have shown interest in it, said Adam Berrey, vice president of marketing and strategy at the company.

He said: "The most significant thing about Silverlight is that it basically puts the... Windows Media Video format in the browser in a really seamless way. The reason we haven't supported Windows Media Video until now is because we felt that the user experience wasn't there."

Brightcove will continue to build all its software, including tools that enable content providers to upload video to the Brightcove service, using Adobe's Flash and Flex development tools, Berrey said.

CNET News.com's Mike Ricciuti contributed to this report

Martin LaMonica writes for CNET News.com