Microsoft is linking up with Nokia to put its Silverlight plug-in on the Finnish manufacturer's mobile phones – in its latest push to make the technology as ubiquitous as rival Adobe's Flash.

The deal, due to be announced at MIX 08 today, is the first time Silverlight will be available on mobile devices, said Tom Honeybone, senior director in Microsoft's developer division.

The cross-platform Silverlight plug-in lets developers create multimedia and rich internet applications (RIAs) and then run them from the browser.

At MIX, Nokia will demonstrate Silverlight applications on its Series 60 and Series 40 handsets, and announce a beta program for its runtime. Phones with Silverlight should be on sale from the end of this year.

Microsoft eventually plans to include a runtime for Silverlight in its Windows Mobile platform. Although Nokia is not yet one of Microsoft's Windows Mobile handset partners, it's rumoured it will come on board (alongside competitors such as Sony Ericsson and HTC). Meanwhile, Microsoft chose it as the company to bring Silverlight to handsets because of its leading market position.

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.

AOL is another company expected to demonstrate a Silverlight product at MIX. It has said it will unveil a free webmail product built on Silverlight 2.

Microsoft developed Silverlight as a rival to Adobe's Flash browser plug-in, 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 released Silverlight 1.0 in September 2007 for browsers running on Windows, Linux and the Mac platform.

Microsoft recently renamed its forthcoming 1.1 version 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 could even be available this week at MIX, although Microsoft has not confirmed this.

In the battle to spread Silverlight, the company is using it on its own websites to add extra rich media content. It's also been using Silverlight as the delivery mechanism for some company-generated video.

Although users can ignore Silverlight for other content, they will need to download it to see at least some videos, including CEO Steve Ballmer's keynote webcast live from the Microsoft's Windows Server launch last week.

Original reporting by Elizabeth Montalbano, IDG News Service.