One of the first things a lot of folks will try after installing the developer preview of Windows 8 will be the IE10 browser—the most used tool in Windows. IE 10 in the preview is Platform Preview 3 of IE 10.  You can read on the IE blog about the HTML 5 engine work we’re doing. This post is about a big change in Metro style IE, which is the plug-in free experience. In Windows 8, IE 10 is available as a Metro style app and as a desktop app. The desktop app continues to fully support all plug-ins and extensions. The HTML5 and script engines are identical and you can easily switch between the different frame windows if you’d like. Metro style IE provides all the main navigation keyboard shortcuts and mouse support you’ve come to expect—creating tabs, moving between tabs, closing tabs, entering addresses, searching, and more. I’m using this browser full–time, and given the amount of time I spend in Windows Phone, the same experience and use of touch is definitely a plus. But you can decide on what works best for you, and not compromise. Dean Hachamovitch, who leads the IE team, wrote this post.  
--Steven
For the web to move forward and for consumers to get the most out of touch-first browsing, the Metro style browser in Windows 8 is as HTML5-only as possible, and plug-in free. The experience that plug-ins provide today is not a good match with Metro style browsing and the modern HTML5 web.
Running Metro style IE plug-in free improves battery life as well as security, reliability, and privacy for consumers. Plug-ins were important early on in the web’s history. But the web has come a long way since then with HTML5. Providing compatibility with legacy plug-in technologies would detract from, rather than improve, the consumer experience of browsing in the Metro style UI. 
The reality today is that sites are already rapidly engineering for a plug-in free experience. Google, for example, recently launched their HTML5 YouTube site for phones. A previous IE blog post discussed how plug-in free sites are becoming more mainstream, and what sites can do to run plug-in free. We examined the use of plug-ins across the top 97,000 sites world-wide, a corpus which includes local sites outside the US in significant depth. Many of the 62% of these sites that currently use Adobe Flash already fall back to HTML5 video in the absence of plug-in support. When serving ads in the absence of plug-ins, most sites already perform the equivalent of this fallback, showing that this approach is practical and scalable. There’s a steep drop-off in plug-in usage after Flash, with one control used on 2% of sites and a small collection of controls used on between 0.5% and 0.75% of sites.
On Windows 8, consumer sites and “line of business” applications that require legacy ActiveX controls will continue to run in the desktop browser, and people can tap “Use Desktop View” in Metro style IE for these sites. For what these sites do, the power of HTML5 makes more sense, especially in Windows 8 apps. 
Plug-in free browsers today already deliver great experiences with well-authored HTML5 content. These experiences get even better with touch in Metro style IE.
Thanks –
Dean
P.S.  Below, you can see how IE adjusts its behavior site by site, as developers make the transition and stop relying on plug-ins for functionality available in HTML5 (for example, video or XHR). Most sites work fine in IE without plug-ins; others work fine in IE when IE identifies itself as another browser or runs the site in a different mode. As we work with the web developer community, IE continues to use the Compatibility View (CV) list to keep sites working for consumers.
Here’s a fragment of the CV list that went live with the developer preview build of Windows 8 at the BUILD conference:


    1152921504606910005
    1
    monster.com
    pbskids.org
    nate.com
    bankofamerica.com
    wellsfargo.com
    7-eleven.com
    sportsillustrated.cnn.com
    lowes.com
    github.com
    dodge.com
    krispykreme.com
    youtube.com
    tv.slashgear.com
    mashable.com
    tested.com
    about.zappos.com
    airborne.gogoinflight.com
    aol.com


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