Party's over: Microsoft Silverlight support ends on October 12, 2021

Silverlight was intended as a Flash killer. What Microsoft didn't predict was that Flash itself (and any plug-in based alternative) would be killed by the iPhone.

I think Microsoft's strategy in the early 2000's was to use the market dominance of Internet Explorer to block web technologies (html/css/js) from improving, and instead push more advanced features though a platform they fully controlled. They might have gotten away with it, if it wasn't for that meddling iPhone.