by , 12:10 PM EDT, September 5th, 2007

Microsoft announced the immediate availability of Silverlight, the company's cross-platform plug-in for Web browsers, on Wednesday. Silverlight is designed to deliver streaming audio and video content as well as Web-based interactive applications, much like Adobe Flash.

In addition to being Mac OS X and Windows compatible, Microsoft is also surprisingly working on a Linux version of Silverlight as well.

Silverlight is PowerPC and Intel-based Mac compatible, and requires Mac OS X 10.4.8 or higher. The plugin is compatible with Safari, Firefox 1.5, and Firefox 2. It is free, and available for download at the Silverlight Web site.