At PDC 2009, Microsoft demonstrated Silverlight video streaming to an iPhone. While Microsoft user experience platform manager Brian Goldfarb said that Microsoft "worked with Apple" to make it happen, don't expect plug-ins for Mobile Safari to start flooding the App Store. Instead, Microsoft worked to make its IIS7 server software capable of sending an QuickTime-compatible stream to an iPhone embedded with a HTML5 <video> tag.

Though Silverlight is more than just a video format—it's more of .NET authoring runtime for web-based applications, much like Flash as become—its media delivery features are what content providers wanted on the iPhone. "The promise of Silverlight is that it's a cross-device, cross-browser, cross-platform solution, and it works the same on Macs as it does on Windows," Goldfarb told BetaNews. "The iPhone is a unique scenario. We talked to our customers...and they said, 'Look, we just need to get our content there, and it's mainly in the media space like broadcasting, and we want to put it on the iPhone.'"

The true extent of "working with Apple," though, has more to do with making sure the system would work and that Apple didn't disapprove. "We did all the work," Goldfarb said. "We just made sure Apple was comfortable with it. We have to have a strong partnership with our partners, we have to have trust, and that's key."

What Microsoft did was enable IIS Media Services respond to requests from an iPhone and transcode on-demand to H.264 format in an MPEG-2 transport stream, the exact same format used by Apple's proposed HTTP Live Streaming protocol. "So it's the same IIS smooth streaming content, the same server, the same point of origin, but now I can get that content to play without any code changes, without any real work, on the iPhone," Goldfarb explained. "That's the critical thing for our customers."

We won't be seeing an Silverlight runtime (nor a Flash one, for that matter) popping up on the iPhone. But content providers already using or considering IIS Media Services won't have to encode video separately or maintain a separate content delivery system for serving their content to the hottest mobile platform. So the real question is, when can I start streaming Netflix to my iPhone?