I have worked with many of my customers on their web applications with .NET, and have personally developed an ASP.NET application for a local school system. One area that has been consistently challenging is adding rich media web content to these web applications. First it is not always easy to do it the way you want or the users like. Second, when you try to put it to work for different versions of browsers such as Microsoft IE, Firefox and Safari, with different media players such as Microsoft's Windows Media Player, Adobe's Flash, Apple's QuickTime and RealNetworks' RealPlayer. With the introduction of Microsoft's SilverLight web technology, this challenge has essentially been addressed.
Microsoft SilverLight, codenamed WPF/E, is a subset of the latest version of the .NET framework 3.0. With Microsoft Expression and Visual Studio .NET, users can easily create SilverLight web applications aka Rich Internet Appliations. When a SilverLight application is delopyed to and run on the web, a small set of programming code about 1.5 MB in size is downloaded to a user's computer at first time use but once only, much like the way of how other Internet plug-in applications such as Flash work. Silverlight is a cross-browser, cross-platform plug-in for delivering rich media and interactive applications for the Web, and supports all major browsers running on the Mac OS or Windows.
To run silverlight code yourself, download a Orcas beta 1 VPC, install Silverlight 1.0 beta and/or 1.1 alpha, and download sample code from Brad Abrams's blog. Note that in order to enable sound on the VPC, you'll need to install a Sound Blaster 16 driver. See instructions.