Looking to create something a bit similar (but not as complicated as this):

http://www.roomsoutdoor.co.uk/configurator

What I would be needing is the ability to stretch the floor plan, windows, doors, have elevations, drag icons in & be able to write on or over the plan.

I notice this site uses Silverlight, but I was wondering what, if anything else, could be used to create something like I need?

I know jQuery can do some neat stuff, but could it do anything like I wanted? What about using a HTML5 Canvas?