By Paul Annesley

Moonlight – Open Source Silverlight on Mono

By Paul Annesley

We have many proponents of open source, cross platform software in the SitePoint community, and I think Microsoft have left some of us scratching our heads over where to stand after unveiling Silverlight and the Dynamic Language Runtime (DLR).

Microsoft’s DLR is a layer on top of their Common Language Runtime (CLR), which provides support for dynamically typed languages such as Python, Ruby and JavaScript. The great news is that the DLR is released under Microsoft’s Permissive License – their way of saying open source. Microsoft’s .NET/DLR implementations of Python and Ruby, named IronPython and IronRuby respectively, are both covered by the same Permissive License as DLR.

Microsoft describes Silverlight as “a cross-browser, cross-platform plug-in for delivering the next generation of .NET based media experiences and rich interactive applications for the Web. Silverlight offers a flexible programming model that supports AJAX, VB, C#, Python, and Ruby, and integrates with existing Web applications.” That all sounds great – cross platform, cross browser – but unfortunately it’s missing the magic words “open source”.

Even so, it’s hard not to be a bit excited about the prospect of a ubiquitous platform/plugin which brings together dynamic languages like Ruby, Python and JavaScript to the client side of the web. And with some of the vital components already open source, it should make it easier for somebody else to take it the rest of the way…

Enter Mono

Mono is an open source project which has been around for quite some time now, which provides the necessary software to develop and run .NET client and server applications on Linux, Solaris, Mac OS X, Windows, and Unix. It is a commonly used solution for running .NET web applications on Unix servers.

It seems that Mono have some well laid out plans, and already some work in progress, for a Mono-based implementation of Silverlight, developed under a project temporarily named “Moonlight”. With Mono’s existing solid support for .NET, combined with the open source DLR code from Microsoft, this sounds like a project to keep an eye on.

  • First of all , MS Silverlight needs to track down the multi-layer bugs , than it needs time and patience to test and realise its usefullness. Mono is arround 5 years now and I think its own status is not so much in the active web as it should have. Well with the hope that every technology need some open space to grow and flourish, I too bet on MONO’s Moonlight Project.

  • wwb_99

    So why is “open source” such a magic word?

  • anonymous

    Well, someone could modify the mono implementation of silverlight to output svg instead of xaml.

  • Anonymous

    cannot see what the noise is about? just another way for those microsoft developers to infringe in our area of development, so nothing new there… but as with all things microsoft you need to be aware of possible (obvious?) security issues that are common with new software releases from microsoft.

    what a gotcha huh? that should be enough of a warning for anyone who is going to jump in with both feet… anyways, at the end of the day your either with microsoft or not, so it splits about even doesn’t it?

    > So why is “open source” such a magic word?

    i mean, between propriety and open source technologies.

    dr livingston, as always :)

  • > So why is “open source” such a magic word?

    Open source provides freedom, especially to developers. (That’s us).

  • wdny

    Exactly why is open source such magic word, that doesn’t make any sense.

  • I like freedom. Maybe that’s just me.

  • wwb_99

    @Dr. Livingston:

    I was not aware that someone “owned” the rich client sphere of development. Or do you like being stuck with a single solution in that space?

    Insofar as security goes, MS’ record of late has been very, very good. Arguably better than linux or apache. Nevermind RoR or PHP.


    One can argue open source provides freedom. One can also argue that open source projects are often too chaotic or too poorly documented to be usable. It is a tool in the arsenal, but it is not a panacea nor a magic bullet for making good software. You need just as much, if not more, dedicated project management to bring a solid open source project to fruition as you need to make a solid closed source project to fruition.

  • Well… I said this was one to keep an eye on, but I didn’t expect to see a result quite so soon.

    Implementing Silverlight in 21 Days – Miguel de Icaza’s web log

    Incredible work from the Mono / Moonlight team.

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