Just found out about SuperPreview:
What is SuperPreview?
SuperPreview speeds browser compatibility testing
Expression Web speeds the essential task of browser compatibility testing. With SuperPreview, you can debug your pages on the same machine that you use for development. You can view your pages in multiple browsers simultaneously or view how a page renders in a browser and compare it to a comp or mock-up image of a page. SuperPreview includes a local client as well as a Web service.
SuperPreview not only shows a high-fidelity rendering of how pages will look on different browsers, but it also identifies the element’s tag, size and position, applied styles, and location in the DOM (Document Object Model) tree so you can quickly fix the error.
SuperPreview installs with Expression Web. You can easily test pages at any stage in the design process, and launch SuperPreview from directly from Expression Web.
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