Microsoft Silverlight is a powerful development tool for creating engaging, interactive user experiences for Web and mobile applications.

Microsoft Silverlight is a free plug-in, powered by the .NET framework and compatible with multiple browsers, devices, and operating systems, bringing a new level of interactivity wherever the Web works.

Media - The highest quality interactive video experiences both live and on-demand across multiple formats while protecting valuable content.

Business - Create business applications that give users richer, deeper interactivity using the skills and tools developers already know and that work the same everywhere–without the usual IT hassle of deploying across multiple OS's and browsers.

Mobile - Build compelling touch-based apps built quickly using familiar tools and distributed through the Windows Phone Marketplace.

Limitations:
Offers to set Bing as your search engine and MSN your homepage by default.