Significant Enhancement in Internet Explorer 9


Microsoft announced Internet Explorer 9 Release Candidate on  Feb 10th, 2011, RC indicates except bug fixing, there would not have big changes before the final RTM. Since I've been keeping a watchful eye on IE9 from its very first preview version, I would like to write a post about its significant enhancement from a developer's point of view, I intend to summarize most significant enhancement points of IE9 listed below:

  • Enhanced performance
    1. The New Chakra JavaScript Engine
    2. Hardware Acceleration
  • Enhanced Web Standard Support
    1. HTML5 (huge number of new attributes support and Web Storage support)
    2. CSS3 (border-radius, ::selection pseudo-element, )
    3. W3 standard Geolocaltion API
  • Windows 7 Integration
    1. Website customizable TaskBar Jumplist.

By achieving new features above, IE9 will absolutely be the fastest and best Web Standard support version in the entire IE history.  

Walk through IE9 Enhancements

New JavaScript Engine – Chakra

IE9 team must be persistently working so hard on improving Chakra's performance, I picked following two paragraph  from Chakra Page on Wikipedia:

Microsoft's development of the engine was in response to evolving competing browsers, on which IE8 was lagging behind in terms of JavaScript processing speed.[3] SunSpider tests performed on November 18, 2009 showed the PDC version of IE9 executing scripts much faster than IE8, but slower than respectively Firefox 3.6, Chrome 4, and WebKit Nightly.[4] The same test performed on March 15, 2010 showed the first IE9 Platform Preview (using the then-current version of Chakra) to be faster than Firefox (with SpiderMonkey), but slower than respectively Safari (with SquirrelFish Extreme), Chrome (with V8), and Opera (with Carakan)

On February 8, 2011, the test showed the IE9 Release Candidate (using the current version of Chakra) to be faster than Safari, Firefox (with TraceMonkey), Opera, and Chrome.

You can image there was a "steep curve" done by Chakra to catch up the competitors in the market: V8, TraceMonkey, etc.

WebKit SunSpider version 0.9.1 results generated February 8th 2011 (From slowest to fastest)

Detailed Results Average (ms)
IE8 3746
Firefox 3.6.13 753
Safari 5.0.3 310
Firefox 4.0 Beta 11 254
Chrome 10 Developer 248
Opera 11 240
Chrome 9 238
IE9 Release Candidate 209

IE9 is cutting edge in all modern Web Browsers in WebKit SunSpider test.

Hardware Acceleration

In general, the "Hardware" is the GPU, from the page All Around Fast, they said:

Today's websites and browsers only use about 10% of the processing power your PC has to offer. Internet Explorer 9 unlocks the other 90%. With Internet Explorer 9, we're tapping into your graphics processor through Windows to harness the full potential of your PC. It makes HD video smoother, colors truer, graphics clearer, and websites more responsive.

More specific, on IE9 Guide for Developers they described:

Internet Explorer 9 uses the DirectX family of Windows application programming interfaces (APIs) to enable several advances for web developers. We have moved all graphics and text rendering from the CPU to the graphics card by using Direct2D and DirectWrite.

Well, how faster IE9 does by utilizing GPU's power? Please take a look at this Video.


By running an HTML 5 support test at, IE9 RC scored 116, it is a pool score comparing to most other modern browsers (refer table below), however, much much better than IE 8 and below…

HTML5 Standard support test (From best to worst)

Web Browser HTML5 Test Score
Google Chrome 10.0 Dev 244
Firefox 4.0 Beta 11 197
Opera 11 177
Safari 165
IE9 116
IE8 37
IE6 12

IE9 RC now support a lot of brand new HTML5 attributes like header, aside, nav, section, footer, and HTML5 canvas, for more details you can refer HTML5Test or Internet Explorer 9 Guide for Developers.

Web Storage

Web Storage is a brand new HTTP state storage strategy implemented by Session Storage and Local Storage, they are 100% stored in the client by a concrete browser, it is obvious bandwidth is saved and security risks are reduced by doing this. IMHO, this is one of the greatest improvement of HTML5! I will write another post delve deep into Web Storage to explain my opinion.

Now IE9 RC has completely supported sessionStorage and localStorage, Invoke sessionStorage and localStorage in JavaScript is fairly easy, sample code showing below:

localStorage.{key} = strValue;
var localVal = localStorage.{key};

sessionStorage.{key} = strValue;
var sessionVal = sessionStorage.{key};


IE9 RC brought great CSS3 support such as font-face, namespace, border-radius, ::selection pseudo element, especially CSS3 selector, IE9 RC "Passed 574 out of 574 CSS3 selector tests", whereas Chrome 10.0 Dev passed 558.

I write a IE9 CSS3 support page which demonstrates font-face, border-radius, ::selection and selectors, HTML5 source code pasted below, please feel free to have a trySmile

<!DOCTYPE html>
<html lang="en">
    <meta charset="utf-8" />
    <meta name="application-name" content="Wayne IE9 CSS3 Support Demo" />
    <title>Wayne IE9 CSS3 Support Demo</title>
    <style type="text/css">
            font-family: "Blue Highway";
            src: url( format("truetype");
            background-color: rgba(100,50,0,5,0.5);
            font-size: 16px;
            font-family: "Blue Highway" ,Arial,Tahoma;
            width: 150px;
            height: 100px;
            padding: 10px;
            margin: 0 auto;
            border: 3px dotted #666;
            border-radius: 10px 10px 10px 10px;
            background-color: #E1E87A;
            color: Black;
        /*CSS3 selector*/
        img[alt*="ie9"] /*all div elements that have a alt attribute value containing "ie9"*/
            border: 3px solid #4169E1;
    <header role="banner"></header>
    <aside>CSS3 border-radius demo:</aside>
    <div class="elementWithRoundedConor">
        Some text....
    <aside>CSS3 selector demo:</aside>
    <img src="" alt="ie9test" />
    <img src="" alt="FireFox" />
    <img src="" alt="ie9logo" />
    <footer role="copyrightInfo">
        &copy;WayneYe 2011


Geolocation API

One month ago I wrote a blog talking about invoking W3 standard Geolocation API and Google map to track end user's Geolocation (, it described how to implement W3 standard way to track Geolocation with sample JS code), at that time I was using IE9 Beta2 which doesn't support it, now it is excited for me IE9 RC has completely supported Geolocation API! See screenshot below:

By clicking "Allow once", your Geolocation will be collected by the browser and pass to Google map.

Windows 7 Integration

This is really a highlight feature and it is really funnySmile, see screenshot below:

The implementation is easy, add similar meta attributes below and IE9 will register Jumplist on your Windows.

<meta name="application-name" content="Wayne's Geek Life - Infinite passion on programming" />
<meta name="msapplication-tooltip" content="See what Wayne is blogging and sharing:)" />
<meta name="msapplication-starturl" content="" />
<meta name="msapplication-navbutton-color" content="#5f6dbd" />
<meta name="msapplication-window" content="width=960;height=600"/>
<meta name="msapplication-task" content="name=Home;action-uri=;icon-uri=" />
<meta name="msapplication-task" content="name=Album;action-uri=;icon-uri=" />
<meta name="msapplication-task" content="name=Video;action-uri=;icon-uri=" />
<meta name="msapplication-task" content="name=History;action-uri=;icon-uri=" />
<meta name="msapplication-task" content="name=Visit Record;action-uri=;icon-uri=" />
<meta name="msapplication-task" content="name=About Wayne;action-uri=;icon-uri=" />

Microsoft's official guide How to Create a Basic Pinned Site.


IE9 RC has made a great enhancement on JavaScript execution performance and much better Web Standard (HTML5, CSS3, Geolocation API) support, even more, a seamless integration with Windows 7 Taskbar Jumplist. However, there are still a number of pities, personally I wish IE 9 will going to implement follow HTML5 features:

  • HTML5 form input elements (<input type="email/range/url/time/color etc.") now are completely not supported by IE9.
  • Web Workers which supports long-running scripts that are not interrupted by scripts that respond to clicks or other user interactions.
  • Server-Side events (SSE) is standardized as part of HTML5, which allow servers initiate data transmission towards clients once an initial client connection has been established.


The New JavaScript Engine in Internet Explorer 9

Internet Explorer 9 Guide for Developers

HTML5 Spec

W3 Geolocation API Specification

HTML5 Doctor


I also want to take this opportunity to share two personal tips on developing cross-browser web application related with Internet Explorer.

1. Define "X-UA-Compatible" meta attribute to tell Internet Explorer what "Browse Mode" it should use, example below:

<meta http-equiv="X-UA-Compatible" content="IE=edge;FF=3;OtherUA=4" /> <!--IE will try to use the highest mode available.-->
<meta http-equiv="X-UA-Compatible" content="IE=7;FF=3;OtherUA=4" /> <!--IE 7 browse mode.-->
<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7;FF=3;OtherUA=4" /> <!--EmulateIE7 browse mode.-->

Please refer more details on MSDN article: compatible Property and Defining Document Compatibility.

2. Conditional comments to distinguish specific IE version

<!--[if lte IE 6]>
    HTML code only for IE6 and under, for example, add a special CSS file only
    for IE6(or under); Or, display a information panel to inform user IE6 is 
    seriously outdated:)

"lte" indicates "less-than or equal" which I always use, you can also use "[if !IE]", "[if IE 7]", etc.,  see complete usage in MSDN article: About Conditional Comments.

Happy CodingSmile

Also posted at:




Leave a comment