Estranged Siblings – Silverlight Mobile and the Compact Framework CLR


An illustration that contemplates the cojoined nature of Silverlight and the Compact Framework


At PDC 2008 in the session Microsoft Silverlight 2 for Mobile- Developing for Mobile Devices, Amit Chopra revealed some interesting details about Silverlight Mobile that I haven’t seen written elsewhere.

The presentation mainly consists of “here’s Silverlight running on Windows Mobile”.   The interesting bits are at the end.  I dear reader, present these to you here.


Compact Framework, small but mighty

The compact framework, is small yet mighty.  (Some may say mighty default)

The Compact Framework provides a great deal of rich device integration and sheer programmability. It is a pleasure to create software for.  I even think that Compact Framework based applications have been a reason for customers, particularly in the Mobile Fieldworker areas to adopt Windows Mobile devices.

If you’re a Compact Framework developer like me, you may have been frustrated by the default “yesterday” appearance of the System.Windows.Forms forms engine.  It takes a great deal of work to make forms look good. 

Silverlight, a Framework Apart?

Two frameworks, Silverlight and Compact Framework, so alike, yet so different.

I for one was very excited last year at the thought of a Silverlight (ie WPF) graphics engine being available for Mobile Device development.  I was then saddened to learn that the Silverlight runtime would not be extending the Compact Framework, but would exist in addition to Compact Framework.

This is disappointing news. (I am now showing my disappointed face….beware!) It appears that Microsoft (at the moment) seem determined to give Silverlight minimal access to the device.  This is aligned with the idea that Silverlight is only a competitor to traditional Flash app that runs from a Web page. 

Although this may be acceptable for certain kinds of desktop oriented Silverlight applications, I doubt this is a believable use case for mobile developers.  The power of mobility is not only the ability to access data anywhere, but the ability to talk to the features of the device.

In the presentation mentioned at the outset, there was declaration of the intention to support Webcams, accelerometer and other device features in the future, depending on the support for this on other platforms (eg Windows and Mac). 

So, we are restricted to the lowest common denominator.  You may believe this is for technical reasons.  It isn’t. Because….

Silverlight Uses the Compact Framework!

Diagram of Silverlight Architecture on Windows Mobile

Amit said that the Silverlight runtime for Windows Mobile may be smaller because it may omit certain codecs and it also shares the Compact Framework Clr.    He went on to say that the Compact Framework would be a prerequisite to installing the Silverlight runtime.

A new and nobler purpose for Silverlight Mobile

I give you....Silver-Knight

It’s Microsoft’s belief that targeting Windows Mobile 6.? (Sorry about that WM2003 and 5) and Nokia phones will mean Web users will eschew DHTML and Flash websites for Silverlight ones.  

With the proliferation of device operating systems (particularly that pesky iPhone) I don’t think this is a likely scenario.  Do you?  Well do you?

I’ve I got an idea!  As it’s unlikely Microsoft will backtrack on their “one platform everywhere” philosophy for Silverlight, why not, in addition enable Silverlight as a cutdown WPF for the Compact Framework on Windows Mobile? Microsoft, I know you can!  Doing this would earn the gratitude of all Compact Developers and provide a side benefit to their current Silverlight efforts on Mobile.

Call to Action

If you agree, please add a comment or bookmark this article using the links below, blog about this yourself or email the people at Microsoft.   Amit said they wanted feedback, lets give it!

(BTW Any physical resemblance between Amit and myself is entirely coincidental, so don’t say it)



Microsoft Silverlight 2 for Mobile- Developing for Mobile Devices

Amit Chopra’s Blog (Email) – WIndows Mobile Program Mananger

Giorgio Sardo’s Blog (Email: gisardo @ microsoft  com) – Evangelist for Windows Mobile


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3 responses »

  1. Pingback: Silverlight2 for MobileにおけるDLRのサポートとCompact Frameworkとの関係 - SharpLab.

  2. My hope is exactly yours. A cut down version of WPF for Windows CE. I’m worried in two areas:

    a) Silverlight for Mobile will be tied to the “online” world.
    b) It will be less performant than large WinForm apps (which aren’t particulary nippy themselves).

    I just hope MS consider enterprise applications running on embedded devices as opposed to just consumer mobile apps… although considering they’re targetting Windows Mobile as opposed to CE it doesn’t look like it.
    I’d like to have some reasons not to switch to embedded Linux for future versions but that’s continuing to look like a sensible idea (and the biggest LOL with this is we’d probably get to use a lot of the full framework via Mono this way…..).

    We’re trying to do interesting things in the transport industry and being stuck with Windows Forms isn’t ideal, especially when we’re trying to enable our clients to completely customise their UI and workflow.
    Just try and make a “proper” transparent or circular button in Windows CE or time the creation and showing of a new form with a bunch of controls on it and you’ll see what I’m talking about. 😦

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