We have a scenario where we create floor plans of locations when we visit. The floor plan is finally shown on the web. It's come to the point now where we want to show floor plans but have a key with various items on them, when an item on the key is clicked, the image should highlight all the areas of the floorplan that have that specific item.

I guess we're looking for some sort of open standard javascript lib to deal with SVG (has to work pre IE9 so pure SVG wont cut it) and the floor plans have to be able to be created through a .net application to be deployed on the web.

I'd rather stay away from flash if at all possible to be honest.

Below are a few conceptual images of what we're trying to achieve.