Did you consider the agcore approach

[JoeWood]

Just wondered, rather than an SL->HTML/JS/CSS conversion, did you
consider going the JSIL route. I mean converting XAP files to
JavaScript+Canvas? Not so good in terms of a true web experience, but
probably easier to do and less compat problems across browsers.

[Rob Ashton]

Yes - I did, in fact it was my original thought and I may yet return to it :-)

After a discussion with Kevin Gadd ( the chap who wrote JSIL ), I
decided that HTML or SVG would be easier as they better match the way
in which Silverlight works (retained mode rendering).

The option remains, as rendering is just one concern on top of many,
just to throw in a different renderer and see what happens. :-)

Certainly the fastest way to get off the ground is just to match XAML
inputs with their appropriate HTML inputs - plus there is an easy
accessibility win here too.