Under Ballmer, Microsoft was very much under the impression of “if you build it, they will come”. Silverlight was released because Microsoft didn’t own Flash. Keep in mind this is pre- or maybe circa-iPhone and the canvas tag has only recently been trotted out as a WebKit feature, mainly to support Dashboard on Mac OS X 10.4 Tiger. YouTube was still brand new too, it wasn’t owned by Google yet, and Silverlight was going to be the basis for developing apps on some version of WinCE whose precise name and version number escapes me. To be honest most of my memories of Silverlight run together and primarily for two reasons: while I thought it was cool tech, there were very few sites which used it. I recall a Microsoft video site and almost nothing else. The second reason is Microsoft never fully committed it to any one application other than as web plug-in. I remember the bit about using it in some version of WinCE and I don’t remember if they ever tried to push it for desktop Windows at some point, but I think that was at least on the agenda at some point, with significant overlap with WPF.

I am struggling to remember actual Silverlight applications, the Playboy Archive, and I think the Library of Congress at some point offered part of its collection as a Silverlight application.

It was also a backdoorsy kind of way to limit cool new web applications to Windows. The Mac version was a feature laggard, when it did finally exist, and I don’t know if a Linux version was ever developed, but I’m pretty sure the answer was no for several years. Of course back then Mac and Linux support was considered irrelevant, and the idea of making a native app into a web app to support them wasn’t really taken seriously for a while either. Silverlight would have seen to that cross-platform future never coming to pass had Ballmer had his way, but well, a combination of market forces from iPhones, to HTML5, to Mozilla and eventually Google Chrome really kind of made something like Silverlight and eventually Adobe Flash moot. Flash at least had legacy applications and video streaming that kept it around, Silverlight had to bet on its own future and to a web surfer it just wasn’t different enough from Flash nor did it ever have the install-base of Flash.