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 browsers. 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.
By mid 2011 Microsoft will have released 5 versions over the course of 4 years: the first version was released in 2007; the current version, 4, was released in April 2010 and the 5th version is scheduled for release in the first half of 2011. It is compatible with multiple web browsers used on Microsoft Windows and Mac OS X operating systems. Mobile devices, starting with Windows Phone 7 and Symbian (Series 60) phones, were expected to be supported in 2010.
A free software implementation named Moonlight, developed by Novell in cooperation with Microsoft, is available to bring Silverlight versions 1 and 2 functionality to Linux, FreeBSD and other open source platforms - although some Linux distributions do not include it, citing redistribution and patent concerns.
