.net, microsoft, mobile, silverlight, software development, windows

A Silverlight UI for Windows Mobile 7, backward compatibility in doubt

Note: speculative post; I have no official information on this.

It’s been rumoured for ages; but at this point I would be surprised if the Windows Mobile 7 UI were not built with Silverlight. Consider:

  • Silverlight has to be supported – it should have been in 6.5 – otherwise nobody will take mobile Silverlight seriously
  • WM7 has to have excellent UI design; and WPF/Silverlight is Microsoft’s designer-friendly UI framework
  • Silverlight 4 already supports touch control in the current beta
  • Scaling/Zooming is baked into Silverlight and ideal for a mobile UI
  • If Silverlight is present on the device it would make sense to build the UI with it

If this is right, there are a couple of interesting aspects for developers. It will make Silverlight a more attractive platform in scenarios such as Enterprise roll-outs where the device can be specified.

The awkward question: what about all those existing Windows Mobile apps built either with native code or with the compact framework? Again, there are rumours of lack of backward compatibility. Does that mean that all Windows Mobile 7 apps with a UI will have to be done in Silverlight? That’s what John Biggs says:

WinMo 7 will not run 6.x code. End of story. It is based on Silverlight and .Net. Everything save a few basic programs will not work under WinMo 7. There is no expectation that this will be a “business device” and the focus is currently on games including some XBox Live functionality for gaming and messaging. There will be a Microsoft App store with an easy approval process.

I find this a stretch. I can believe that Microsoft might initially target the consumer market, or have crippled “consumer” versions; but not that it would give up on mobile business apps – we heard at PDC (to the point of tedium) how Microsoft is supporting “three screens and a cloud”, unified for developers by Visual Studio. There’s no reason why Silverlight should not be used for business apps.

What about backward compatibility though? Traditionally Microsoft does a good job of keeping your old stuff running, within reason; possibly too good – Windows is full of compatibility hacks that may be to its detriment overall.

Another point to bear in mind: WM7 needs a browser, and I don’t see Microsoft re-implementing IE in Silverlight.

So I’m sceptical about this too; but with Windows Mobile at such a low ebb could the company decide it has little to lose?