Hi, Talin from Trulia here. For commute, our heatmaps are rendered in canvas, based on JSON data from our servers. This allows for the efficient slider. We al

Hi, Talin from Trulia here. For commute, our heatmaps are rendered in canvas, based on JSON data from our servers. This allows for the efficient slider. We also have static image tiles, for certain (ahem) browsers that don't support canvas. The downside is that they can't use the slider.