SuperPreview Cross-Browser Testing with IE Firefox Chrome Opera
Every web developer today faces the challenge of checking website compatibility across a large pool of browsers and browser versions in the marketplace. Up and until now, either you could install every browser, verify the website via a visual inspection and debug with tools specialized to that browser, or you could send a URL to a third-party screenshotting service like BrowserShots for an all-in-one visual inspection. The former is messy and tedious but gives you more control and an opportunity to diagnose problems, whilst the latter is simple but slow and useless to fix the problem. Needless to say, SuperPreview is the best of both worlds.
Check this blog for more
http://blogs.msdn.com/b/xweb/archive/2009/03/18/microsoft-expression-web-superpreview-for-windows-internet-explorer.aspx