“The (most) obvious question: Why would I install this plug-in rather than switch browsers to Chrome? The folks at Google point to IT lockdown that won’t allow users to install a new browser; Ars wonders whether such restrictive IT departments would be any more likely to approve this plug-in. If nothing else, it’s a pretty bold move on the part of Google.”

If you’re interested, Jim Ray dug into the details of how it works. Personally, I don’t think this will solve anyone’s IE6 problems, but it’s a fascinating development, and worth keeping an eye on.

“The irony here, as I see it, is that an old, insecure feature Microsoft built to try to beat Netscape is now being used by Microsoft’s biggest current rival to patch IE.”

On the IE Blog, Tony Ross published a list of mostly technical differences between the two. Perhaps more useful for web developers is this article by Estelle Weyl outlining some of the presentation differences between the two, such as border handling and box model differences.

Why does this matter? Because I’ve heard some otherwise intelligent web developers (including Microsoft’s Expression Web team, which uses IE8’s Compatibility Mode for IE7 testing) claim that testing will be much easier now, since you can test everything in one place.

To be sure, tools like Expression Web or the old Stand-Alone IE installers are helpful, but don’t fool yourself into thinking that they are an accurate representation of a “clean” IE6 or IE7 installation. To test against those, you’ll still need to resort to more thorough measures like keeping separate machines around, or using the free Virtual PC images for IE6, IE7, and IE8.