Evil SEO said:
*snip*
If I understand it correctly, that's the interesting thing about Expression Web Superpreview: rather than run or emulate other rendering engines, it sends a request for the page to some server, which then renders it on the target platform, and then sends an
image of the output back. So in theory this could mean that you can tell exactly what your page would look like in Safari under OSX (including OSX's fonts and everything) without actually having to own a mac or runs OSX/Safari, because the server will render
it on an OSX machine for you.