Silverlight was Microsoft's Adobe Flash competitor. Released in2007, it was intended to create a more interactive user experience on webpages, similarto Flash which was extremely popular at the time. In 2008, Microsoft.com began encouraging users to install Silverlight witha giant modal popup box on the homepage. Silverlight never achieved critical mass and was later deprecated.Homepage asking to install MS Silverlight (2008)
Source: web.archive.org