> Let me just list some of the stuff IE9 doesn't support:
* Application Cache (offline)
* Web Workers (threads in JavaScript)
* HTML5 Forms (validation mechanism, CSS3 selectors)
* JavaScript Strict Mode
* ForeignObject (embed external content in SVG)
* SMIL Animations (SVG animations)
* File API
* WebGL (3D)
* CSS3 Transitions (for animations)
* CSS3 Text Shadow
* CSS3 Gradients
* CSS3 Border Image
* CSS3 Flex box model
* ClassList APIs
* FormData
* HTML5 History API
* Drag'n Drop from Desktop
...
> Let me list stuff that IE9 can do others don't:
* text-overflow doesn't work in Firefox 4.
* Calc is not supported in Chrome 9.
> So that's why I don't consider IE9 a Modern Browser.