Through a deal it will reveal Tuesday, Microsoft is working with mobile handset provider Nokia to put Silverlight on wireless devices for the first time, said Tom Honeybone, senior director in Microsoft's developer division. Silverlight is a cross-platform plug-in that lets developers create multimedia and rich Internet applications (RIAs) and then run them from the browser.

At MIX, Nokia plans to reveal a beta program for its runtime for Silverlight on its Series 60 and Series 40 handsets, as well as demonstrate Silverlight applications running on the handsets, he said. By the end of the year, Nokia plans to ship handsets with the runtime embedded that can run Silverlight applications, beginning first with the high-end Series 60 smartphones, Honeybone said. Silverlight on Series 40 phones and on Nokia's tablet devices will be available thereafter.

Microsoft eventually plans to include a runtime for Silverlight in its Windows Mobile platform, but it chose Nokia as the first company to bring Silverlight to handsets because of that company's prominent position in the mobile handset market, Honeybone said. "Series 60 is the clear leader, " he said. Nokia is not currently one of Microsoft's Windows Mobile handset partners, though there have been rumors that the company eventually will sign on to build Windows Mobile devices alongside competitors such as Sony Ericsson and HTC.

Microsoft will be developing a portability kit so Nokia can port Silverlight from the desktop to its mobile platform; that kit eventually will be available to other handset providers as well, Honeybone said.

Microsoft released Silverlight 1.0 in September 2007 as a plug-in for browsers that could work on Windows, Linux and the Mac platform. Microsoft developed the technology to displace Adobe's Flash, which currently has about 97 percent to 99 percent penetration on the Web as a technology for delivering multimedia content and RIAs.

Flash also is available on wireless devices as Flash Lite; the technology is available on more than 450 million phones, according to Adobe.

Microsoft recently renamed its forthcoming 1.1 version to Silverlight 2, saying it's more stable and fully baked than merely an incremental release. The company has said Silverlight 2 will be available in beta form in the first quarter of the year. It's not unlikely that release will be made available this week at MIX, though Microsoft has not said this and would not comment Monday.