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.
Also, Netflix. The fact that Netflix required silverlight caused much pain for Linux users.
I guess it was right. Also Netflix.
I remember it being used for Roland Garros streaming and that's pretty much it, I don't think I ever encountered another website using it.
My impression is that Silverlight's whole packaging & delivery model was envisioned to be more wide-spread but didn't take off. Microsoft was thinking that you could write one program, and then easily package & distribute it as a web app (via Silverlight), or a Windows Phone app, or a native Windows app, or an Xbox app. But... Windows Phone died, Xbox never grew from a game platform into a home multimedia platform, and C# did not achieve popularity for user-facing desktop apps. Plus Microsoft churned Windows APIs a few times.
I could easily see an alternate present where Silverlight was more successful for a longer time, if the timing was different or if a few events broke a different way. But I doubt that alternate present is better than this one.
With Windows Phone 7 they used it as a UI layer for just about 1 year, but Windows Phone 8 stopped using silverlight in favor of WinRT(~2011/12).
Xbox never supported silverlight as a development platform in any of its iterations.
You may be confusing the WinRT/UAP/UWP fiasco with silverlight.
It didn't? Because a lot of desktop apps I've used seem to use it, and lately it's even become a reasonable cross-platform option.
I know for sure it's pretty common for games; besides Unity, I know e.g. The Sims 3 (and maybe 4?) uses it pretty heavily (including for mods), as do some more recent games like Mount & Blade II: Bannerlord.
In an alternative universe where Silverlight, instead of Flash, had become the de facto standard before the iPhone, I suspect we would likely have moved onto something like OpenSilver instead of HTML5 as the backbone for web applications.
Flash was designed for tiny animations and somehow became an application platform. Sikverlight was actually designed as an application platform and it showed, in how much better it was.
The DirectX controls you could use in Internet Explorer were a thing for a while.
The most interesting thing for me about all of this remains that WebAssembly ultimately became one of, if not the first write once, deploy anywhere standard that the major browsers agreed on (after implementing their own versions of it in a reasonably similar way).
So if you desperately wanted to do the "render stuff client side to a canvas on the web using a good programming language" then Silverlight wasn't half bad. The programming model/layout/concurrency handling etc was every bit as good in 2005 as modern js/react is 15 years later, but the tooling was much better. Think of it as vb for the net. You could fire up your development environment and create a new interactive app and compile it to a single deployable file in minutes.
I used it quite a lot, but that was for things like internal apps. It was pretty good as a deployment model for e.g. a complicated dashboard on an intranet page.
Not true. silverlight never supported linux, unless you count the mono-based moonlight, which was buggy and didn't support DRM, so didn't work for the most common sites that used silverlight (like Netflix). Flash, on the other hand, supported linux for a long time.
But they made not even a token effort at cross-platform, so it was a walled garden. People had only just broken out of the last MS walled garden, and did not relish entering another.
2005 was a strange place.
Flash had its problems, but why would anyone instead use another proprietary system that works on fewer platforms?