These are actually Smooth Streaming files.

http://www.iis.net/extensions/SmoothStreaming

FWIW, Silverlight 3 supports WMV, MPEG-4 (with H.264), Smooth Streaming, and supports managed code decoders and parsers to add additional formats.

What else would you use if you wanted to do cost-effective live HD streaming?

Media companies who use Silverlight are mainly using it to do stuff there aren't any other ways to do.

We're seeing a huge amount of live sports projects using Silverlight, because nothing else can deliver the same experience economically.

Her's a bunch of high-profile projects: http://team.silverlight.net/

Becase more context makes it easier to learn and retain the information, and to explore further in topics of interest?

This is web video; we should offer more than VHS interactivity and richness.

Well, here's an actually serious question.

What kind of DRM implementation would the Linux community accept in Moonlight?

2000 or so? Probably when always-on broadband become common.

Certainly XP as released was way too trusting. But I think Microsoft's track record has been quite positive since XPSP2. I wasn't around for that period, but it definitely got people VERY focused on security as something that has to be baked into product design from the inception of the product. Vista, IE 7/8, Silverlight, Office 2003/2007 all have had much better security records than their predecessors.

Lots of complaints about Microsoft products, most notably Vista, are on areas where Microsoft prioritized security over simplicity or backwards compatibility. And that's a problem for everybody, including Mac and Linux, with years of regular security updates ahead of us.

It's been easier in Silverlight since there wasn't anything to be backwards comaptible to. But there are defintley features that have been cut, delayed, or reduced in scope due to the test cost of verifying security. Every feature gets a threat model and security test plan before it gets approved.

We're really serious about it. On the media side, for example, there's a lot of fuzz testing of malformed bitstreams to make sure there's no way to cause a crash that could then lead to an exploit.

Check out some links to the player in action. It does a whole lot of stuff that MPlayer can't.

It's really more like a Blu-ray or Director style media playback application. It's not just a rectangle with some codecs.

Sure it can. Check out the player experience, and its navigation, commentary, captioning, etcetera. And it uses Smooth Streaming to provide proxy-cachable video at multiple bitrates.

http://alexzambelli.com/blog/2009/03/27/smooth-streaming-white-paper/

FWIW, Silverlight so far has had 0 exploits over three versions. It's done well compared to other media players in the same period. One advantage of a relatively recent technology is that it was designed for security from the get-go, after the web had shifted to its current "presumed hostile" state.

What browser do you use?

Also, if you look at the design of the video experience, it really couldn't be done without Silverlight. This isn't just a simple video player, but with integrated captions, commentary, graphical links, and delivered via Smooth Streaming.

It's really a media player app using Silverlight as the runtime; there's certainly many thousands lines of source for the managed code driving that experience.

The video codces in Silverlight 3 are H.264 (ISO standard) and VC-1 (SMPTE standard). So, they're open specifications but the patents are licensed from MPEG-LA.

Moonlight offers to download fully licensed binary implementations of the Silverlight codecs from Microsoft.

200+ is for all the developer goo.

The Client Profile for .NET 3.5 SP1, which is all that's needed to install a .NET app on a machine that doesn't have .NET 3, is 28 MiB.

http://msdn.microsoft.com/en-us/library/cc656912.aspx

And Silverlight is less than 5 MiB if the app can run entirely in the Silverlight sandbox.

Mono is 75 MiB on Windows, 56 MiB on Mac, . Moonlight is (really?) 941 KiB.

But none of the cable/sat set top boxes do Part 2, and there are tons of those. And they account for many, many more eye-ball hours than Part 2 on DVD players; most users have probably never watched a "divx" file off disc.

Flash and Silverlight don't have Part 2 support. QuickTime does SP, but not ASP.

I'm confident the number of H.264 players in use today is substantailly bigger than for MPEG-4 part 2.

Actually, H.264 advantages are bigger the lower the bitrate. The combination of the in-loop deblocking filter and CABAC entropy coding make a huge difference at low bitrates.

No, I bet H.264 has more decoders out there than MPEG-4 ASP. There're certainly much more content, and more authoring tools.

ASP really only caught on in the piracy scene.

Plus MPEG-4 Part 2 is also licensed by MPEG-LA, so it doesn't address licensing issues, but it'd a lot weaker codec than H.264.

Silverlight 3's Raw AV pipeline should be able to support Ogg Theora/Vorbis:

http://on10.net/blogs/benwagg/Silverlight-3-Beta-Whatrsquos-New-for-Media/

Someone's already working on a port of the Ogg wrapper and Vorbis for Silverlight and Moonlight:

http://veritas-vos-liberabit.com/monogatari/2009/03/moonvorbis.html

No need for conspiracy theories. Theora doesn't solve any problems for Apple.

Theora won't work in iPods, iPhones, or AppleTV.

And Theora is less efficient than even H.264 baseline, and so would raise their (presumably quite substantial) bandwidth costs for delivering video content.