Microsoft Silverlight is an application framework for writing and running browser plug-ins or other rich internet applications, with features and purposes similar to those of Adobe Flash.
The run-time environment for Silverlight is available as a plug-in for most web broswers. While early versions of Silverlight focused on streaming media, current versions support multimedia, graphics and animation, and give developers support for CLI languages and development tools.
Silverlight is also one of the two application development platforms for Windows Phone 7.