Just as its predecessor, Internet Explorer 9 comes with Compatibility View, a feature illustrative of Microsoft’s commitment to not breaking the web with new iterations of IE.
Compatibility View, along with the multiple rendering options in IE8’s successors, make sure that customers can still get a great experience on older websites in IE9 RTW, even if said sites were tailored to IE7 or IE6.
Not only did the Compatibility Feature make it into IE9, but also the associated Compatibility View List.
With the Compatibility View List, Microsoft maintains a collection of sites that are, to some degree, incompatible with IE9 in terms of rendering.
