IE9 will support opacity

On August 18, Ted Johnson (Microsoft's Program Manager Lead for Web Graphics) announced on the IE blog that the IE9 browser would support the CSS3 Color module , and in particular, maintain the opacity property instead of its own alpha micro-filter. However, alpha filter support will remain in compatibility modes (Quirks, IE7 and IE8), for which, on the contrary, opacity is not planned for implementation.

Thus, in order for CSS to work in all versions of Microsoft Explorer, it’s enough to describe transparency with two properties in a row:

. Some Class {
opacity: 0.3;
filter: alpha (opacity = 30);
}

If you specify transparency not using CSS, but using javascript, then be careful that the script does not assume that all versions of IE understand filter and do not understand opacity : this assumption will be wrong with respect to IE9. Instead, Ted Johnson recommended using the opacity property in scripts, depending on the value of some (pre-computed) variable, which determines whether the browser supports this property:

var useOpacity = (typeof document.createElement ("div"). style.opacity! = 'undefined');

For more detailed examples you can refer to his blog.