Silverlight enables development of the next generation of Microsoft.Net-based media experiences and Rich Interactive Application (RIA) for the web. Application which is created by Silverlight is cross-platform and cross-browser plug-in that expose a programming framework and feature that are subset of the .NET framework and WPF. Microsoft Silverlight provides functionalities similar to those in Adobe Flash, integrating multimedia, graphics and animation. The plug-in required running Silverlight is very small in size which is approximately 4-5 MB for windows and 12 MB approx for Mac Os.
Different versions of Silverlight
Silverlight 1: Silverlight 1, which was developed under the codename Windows Presentation Foundation/Everywhere and released in 2007 which consist of basic packages of presentation framework which is responsible for creating UI and interactive user input and media support.
Silverlight 3: Silverlight 3 includes a number of controls for creating a user interface which is not limited to DataGrid, TreeView, various layout panels. Silverlight also contains a special control for navigation purpose which is known as navigation framework. On the media support point of view it supports advance audio coding decoding as well as hardware accelerated for video decoding.
Right now Microsoft had already launched beta version of Silverlight 4 which contains various rich functionality related with user experience. It directly support for Google Chrome, Web cam and printing support etc.