Any plan to open sourcing Silveright?


Any plan to open sourcing Silveright, almost forgot by all.


Probably little point.

If you’ve already sold stakeholders on silverlight they’re happy with closed source runtime, it ain’t really going to exist outside of enterprise.

As silverlight is dead from here on out, no one is going to start any greenfield or startup on it, I presume it would be difficult to split the DRM components too (ala moonlight).

Netflix is saying good bye, probably the last real consumer of use of the flash like bastard… There exists more interesting codebases to analysis from an historical pov… let it rot.


I would like to ask that we focus on the world of possibilities: What we can do to change the world, as opposed to finding reasons why something should or should not be done.

The former has the potential of changing and reshaping the world. The latter is known as Stop Energy and rarely leads to the world advancing. It merely accepts the status quo.

I like to think that this is a new era for .NET and for .NET developers.

It does not hurt to ask the question. And if it ever got open sourced, I am sure that it could be successful beyond the original intended model. Even without media codecs, an open source Silverlight is useful in hundreds of scenarios.


I think any advancement of Silverlight, or Moonlight, or MS rewrapping of it under a new open source ecosystem would be disruptive towards an open standards web, much larger than ecosystem of .NET and .NET developers.

We’re moving in the right direction, browser plugin advancement can only be seen as a problem for that, and like jquery templates it probably the last thing MS want to be blamed for during this risky change.

If only stop energy was in play in 2008 when we had wpf/everywhere

Everything else is cool, positive, but silverlight…


As a former Silverlight developer and current user of cross-platform .NET technologies, I think this is a really interesting question. The state of .NET technology today means that you can develop native apps using .NET for pretty well all the major platforms, and the support for doing so is clearly improving. The big missing piece there is the web. There are some projects out there that make a start at it, and there’s also ASP.NET, but nothing that really occupies the space Silverlight did so well. Could the Silverlight codebase be a starting point for an analogous technology that works in a plug-in free way? Can you imagine having .NET style development and sharing code across native and web apps? Seems like something worth thinking about to me. Microsoft is pretty clearly in maintenance mode with it, and browser plug-ins are going the way of the dinosaur; what would open-sourcing it really hurt?


I don’t think it would hurt per se, unless it caused a significant revival. When MS put their weight behind open source they started with jQuery [subjective] and they caused the mess of jQuery templates, but with Scott Gu and Hanselmann promoting it the atrocity managed to get headway for a number of months/years, looking back everyone WTFs? It would be a shame if an open source of silverlight and a revival of an ecosystem caused similar problems, but I do suspect nowdays it would be roadblocked pretty fast, this in part a PR war afterall. A more interesting idea would be recompilation to typescript or javascript and a HTML5/CSS3 component set modelling silverlight 3.0+

Releasing silverlight as reference source for those interesting would be cool, but I suspect most can be learnt from moonlight anyway


Who said anything a browser plugin?

That is the problem with stop energy, you do not engage your imagination.

Silverlight can be used out of browser.


Fair point. Adobe Air would be a good example for a very similar out-of-browser experience that ultimately was hyped, failed, and pulled, why would an OSS-Silverlight win over this? Why would Ubuntu, Fedora, Apple with OS X, include out the box support? Is there anything magical that existed in moonlight that would woo cross-OS developers? Does this not compete with Ximarin too?

Reality is it won’t work, but its not important anyway since HTML5/ES6/CSS3 already there… It would be cool to see the engineering in SL 1.0/2.0 and 3.0 (and it was enough to win me over) but I see no future on a basis of merits… And it is worrying that “no harm releasing it” then meme can cause the same damage as jQuery templates, i.e. many people bite tongue because this is MS contributing but holy yikes this is terrible…


@nonuby it’s not for you to decide if open sourcing Silverlight would or wouldn’t be useful to someone else. If you yourself lack imagination and creativity to see how all or just parts (no matter how small) of Silverlight source would be used then step out of the way.


Also, it could be used IN the browser, with something like JSIL and a WebGL/DOM renderer.


This is interesting because I have been saying with the announcement of open sourcing .NET that I believe the more important part is that Microsoft is officially supporting cross platform .NET by bringing it to Mac OS X and Linux. The thought is that cross platform would initially at least expand the reach of .NET more than open sourcing it. Silverlight however, is already cross platform. It runs on Windows and OS X in the browser and also powers Windows Phone. So it has already proven useful both in and out of the browser. It also is possible to run SL apps out of the browser on the desktop. If SL were OSS and had with it a license that gave developers the freedom to create custom implementations, then I agree that using the previous applications of SL as motivation, that it could go places that Microsoft didn’t intend it to. During an interview on the VS Connect event earlier this week, Scott Hanselman said that the best practices won’t always come from Microsoft. Also, many inventions (like velcro) don’t end up staying in their domain in which they were originally imagined. So OSS can (and already has) proven to generate new ideas and I think that SL could be the ideal project to go open next. Granted, SL is not a great example of a wildly successful framework (especially compared to ASP.NET or C#) but that could be the best ideas on how to use it aren’t coming from inside Microsoft.


When I started with MonoDroid and MonoTouch (today Xamarin.Android and Xamarin.iOS) one of the first sentences that drew my attention were “it is Silverlight profile” and since then all ports of the libraries I needed was simply done in this way:

  1. create Silverlight dll
  2. copy code from original projec/dll to new one
  3. use project linker or manual adding to add files
  4. patch the differences

Silverlight was IMHO excellent tech. The problem is that software went from desktop to server (90’s) and to mobile. Normally it would be from smaller, less powerful to stronger more powerful so mobile to desktop to server and now early adopter companies like Microsoft have to breakdown their tech to pieces to enable “start small and grow (pay) as you need”

I like to explain everything through physics and human mentality is like pendulum. at the beginning everything was [generated] on the server, then we got Flash and great performance in graphics, because it was done locally. Silverlight followed. Then pendulum went other way and everybody said few megs download of flash or silverlight is too much. And those two technologies were doomed…

Today we are downloading javascript and for some sites it is closing to 1 meg of js code which needs to be either interpreted or compiled on the client. OK there are some benefits (optimizations), but what about intellectual property? I think flash and silverlight though not ideal techs they were better than pure js to be decompiled.

OK. Now somebody comes and tells: Standards! HTML, CSS, JS. HTML is not standardized (yet).
Though I prefer standards, the adoption is something that dictates standardization and adoption (dog is biting his tail). I was c++ dev for years and this language was pushed to margins/background because standardization was too slow and while committee was sitting and eating (I don’t want to use other verbs). At that point I realized that algorithm no matter how good it is will not be sold by console textual output, but bu UI. Sometimes Form sells-supersedes Function and this is when I started with c# and .net.

Bottom line - Silverlight was good tech and god starting point for mobile and “even smaller than mobile” = IoT tech. Imagine nuget in silverlight which downloads only mine dlls and if not present in cache downloads rest of the dlls from feeds… I mean this could be standardized easily. And even if not standardized then first accepted (by us) and then the usage/acceptance tidal wave might trigger standardization.

Today I would like to see Silverlight as an option to [not only browser] client side tech (xaml instead of ncurses??? for embedded IoT devices, pushing vectorized XAML through ssh or RDP). I see - over the network partial screen refreshes through XAML injection on IoT devices to reduce network traffic. Then XAML as JAML to reduce overload even more…

The I’d like too see XAML differences between Microsoft part of XAML between WPF and Silverlight cleaned up, so we get true cross platform.
And in the next step[s] to think about XAML4ALL (merging with Xamarin.Forms), xwt etc…

enough I got carried away.




Silverlight was a great way to deploy and update .Net desktop applications out of browser on Windows and OSX. It didn’t have the DirectX dependency of WPF and it worked very well for us until its development stopped.

At the moment a cross platform desktop app is more difficult than a mobile app. Maybe we have to drop the name ‘Silverlight’ but keep the concepts and ideas so that in the future we can have cross platform meaning both mobile and desktop with a high code share.


I’m afraid you may be right about the ‘Silverlight’ name. It has a negative reputation but I agree that the ideas are solid and could be applied elsewhere.


Actually, Amazon Instant Video still seems to prefer Silverlight when it’s available. I’d call that a major consumer use.


An enterprise developer perspective:

Open-sourcing Silverlight would be great. I don’t really see Silverlight being a technology for the web with all that’s on HTML5 (despite all its inherent problems). That’s gone and I dont even want to enter that discussion.

But from my personal experience as an enterprise developer and architect, Silverlight was by far the technology that allow us to deliever more with less effort. And on enterprise projects that really ment a lot. Besides, the app deployment mechanism (running in the browser) was simply great: not only because it drastically reduces deployment effort but also because it provides a consistent usability pattern when mixed/integrated with other/legacy web apps.

I personally believe the goodness on Silverlight is on:

  1. its ability to run inside the browser, therefore provinding the consistent web usability pattern promoting a smooth integration with legacy/other web apps;
  2. its ability to run on many browsers, because the days of IE ubiquity are gone (and trendly disapearing on
  3. of course: XAML and C# (allowing us to reuse our know-how);
  4. and I guess, its ability to run on multiple OSs, despite this was never a “real” requirement for any project I’ve been working on. But it seems logical to consider this a point in favour of Silverlight, considering the apparent increasing of other OS on enterprises.

Hope to see Silverlight open-sourced. (even if Microsoft support ends with v5)


To me, the open-sourcing of Silverlight is a great idea, primarily because of its ability to go cross-platform. (WPF relies upon Win32 and DirectX, so it would be very difficult to convert to a cross-platform framework.) Since Silverlight doesn’t have dependencies on Win32 and DirectX, it would be much easier to convert to a cross-platform framework.

To be clear, I’m thinking about Silverlight in out-of-browser mode, not as a plug-in.

Many developers were very disappointed with the way Microsoft allowed Silverlight to become a second-class technology. I believe many of them would come rushing back if Silverlight were made open source, and the power that is Silverlight were suddenly made available as a tool for the development of cross-platform apps well into the future.

In fact, I believe there would be many new converts to the power of MVVM/XAML/C# if those skills now allowed a developer to create cross-platform apps that were not dependent on a browser.

It would also seem to be in the interest of Microsoft. For one, it would encourage the continuing use of Visual Studio. Second, it would encourage the development of n-tier apps, which require a hosted server, which would lead developers to consider Azure for the hosting of their services. (As opposed to WPF, which caters to client-server apps)


Silverlight should be open sourced, Microsoft will finally made up to customers and developers for its lack of support. Silverlight was not “just” a plugin in a browser, it was used as a WPF Everywhere (much better name). It was used for very complex applications which could be deployed through the browser to multiple OS. If .net is going to be successful a cross platform (real) user interface is needed which can share logic both on the server and the client.

So far javascript is doing the same combining nodejs / commonjs / angularjs etc… why throw something good to the bin?


I am glad to find that there are people who understands Silverlight advantages.

However I think that open sourcing SL (although has to be done for the support reasons) is not the final stop. I think ultimately we need a new cross-platform product which combines those features of Silverlight/WPF that made it great for the devlopers and the businesses (similar to my note on WPF here : Cross platform WPF)…

Ultimately I think we need XAML based cross-platform UI to go with .NET Core and Xamarin (hopefuly MS will use its Xamarin aquisition for exactly this!)


Stop Energy indeed, @migueldeicaza. It never amazes me how much I see this on UserVoice, where its sole intention and PURPOSE is to create IDEAS and SUGGESTIONS! Talk about being a wet blanket. What would happen if we had this position about ANY project that we consider? What if we had this attitude (or as I call it, CANTitude) about Silverlight to begin with? Or WPF? Or Xamarin?! You know, a lot of people said open-source and cross platform .NET would never happen, either. And now a lot of people are saying we can’t put .NET in a browser, but lo and behold it can be done (albeit not as robust or capable is it would be if an entire MSFT division had done this after Silverlight’s strategy shaft, erm shift in 2010 as they should have done – but I digress!)

Seriously… less stop, people! MUCH more START. This is what innovation feeds from and it truly our duty as developers.

Anyways, before I start getting on a rant (too late?)… Echoing @maxima120 here. It’s time for a new .NET client application development model (which is exactly what Silverlight was – the plugin was simply the delivery/installation mechanism), and I have a feeling after this week’s announcements with Xamarin that we are well on our way.

I think it’s safe to say that we are in for some exciting announcements for this year’s //build and Evolve. :smile:

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