Internet Explorer 8 Released by Microsoft

Microsoft officially released Internet Explorer 8 (external link) to the world last Thursday. Even though IE7 still feels rather new in the web development world, due to its rather slow adoption, IE8 is the first major release of the browser since October 2006. IE8 features:

  • Private browsing mode
  • "Accelerators"
  • Web slices
  • Better page zooming
  • Better RSS reader
  • Developer tools
  • Improvements to the rendering engine, security, and performance

Microsoft have made a number of fixes and improvements to IE's rendering engine in IE8. Finally, IE8 passes the Acid2 test (external link), but it still does not fair well on the Acid3 test (external link), only passing 20 out of 100 tests.

The improvements in web-standards compliancy in IE8 have forced Microsoft to introduce some form of backwards compatibility for sites designed for the past broken IE rendering engines. Developers can add a <meta> tag to their webpage so that IE8 will render it as if it were IE7:


<meta http-equiv="X-UA-Compatible" content="IE=7" />

Before, Microsoft were trying to require websites to add a <meta> tag to use IE8's improved rendering engine, an opt-in style instead of an opt-out. There was a huge uproar because opting-in is extremely counter intuitive to web standards. Therefore, Microsoft went with the opt-out approach, which will help to get more businesses on board upgrading because IE8 is guaranteed to support any proprietary internal software they might be using that is designed for IE7.

Microsoft have also included an icon in the menu bar for websites designed for "older browsers" (aka IE7 and IE6) that when pressed will render them using the IE7 rendering engine.

Overall, Microsoft still feel really behind the other web browsers in the market. Whilst all the other browsers are working on or have passed the Acid3 test, Microsoft has finally just passed the Acid2 test. For how much money and effort they devote to IE, Microsoft just as easily could have popped a new interface over WebKit or Gecko. It would have saved them so much time and money, plus be beneficial for web developers.

Nonetheless, I am personally glad to see Microsoft at least working towards an improved IE8. Simply the fact that they are working on it is a huge relief to me because for so long IE6 sat untouched. Hopefully by IE10, Microsoft will either have ditched the Trident rendering engine for something else or will have discontinued the browser in favour of Opera or Firefox.



  • I can't see them dropping IE in favour of FireFox or Opera. They will likely do a rewrite of rendering engine but I don't see them using a pre-existing browser or rendering engine (like Webkit). They are most likely already working on the next rendering engine.

    Just one think you missed out. IE8 is the only browser to fully support CSS 2.1. All other browsers only implement some of the bits of CSS 2.1, IE8 implements them all. This makes it the most standard compliant browser when you look at CSS 2.1 level. The reason why they do so poorly on the Acid3 test is that CSS3 is the goal of the next version of IE. This has always been something that Microsoft have been aiming for; full CSS 2.1 in IE8 and full CSS3 in future browsers. IE8 also has quite a bit of HTML5 implemented as well; although I'm not sure how much, or what, they have implemented compared to other browsers.

    Overall I really like IE8. I've used it a bit and it's a ver capable browser and renders most things perfectly.

    Posted by Matt Oakes (external link) on Mon 23 Mar 2009 at 18:56

  • I don't think IE8 is the only browser to support CSS 2.1. I'm looking here at Opera's web specifications (external link) and I'm not seeing anything they don't support, but perhaps it isn't as specific as a property or something.

    I think they only reason they are touting that is because they made an extensive testing library, which they submitted to the WC. However, I've read a number of places about how IE8 still has a number of CSS 2.1 bugs ( for a few). But don't get me wrong, they have done tons of great stuff, they're just stretching the truth a bit in my opinion.

    Also, most of the people's compliancy isuses nowadays seem to be directed towards JavaScript, which MS have not resolved yet.

    Posted by Ethan Poole (external link) on Tue 24 Mar 2009 at 17:14

  • (external link)

    Watch IE8 fail. Here's some more:

    Quotation by ""

    Regarding IE 8 support for CSS 2.1 in your conformance results page

    1- Incorrect parsing and rendering of font-size when involving system font in IE 8:
    Testcase and bug report accessible from (external link)

    2- Font-family must not contain unescaped parenthesis:
    Testcase and bug report accessible from (external link)

    3- Font shorthand and inherit keyword are incorrectly parsed in IE 8
    Testcase and bug report accessible from (external link)

    4- Media-dependent @import rules fail in IE 8
    Testcase and bug report accessible from (external link)

    5- Various other import techniques fail in IE 8
    Testcase: (external link)

    6- border-width: inherit test which fails in IE 8: (external link)

    and Iâm sure there are others.

    regards, Gérard

    As you can see there are plenty of annoying bugs left, also related to some fairly basic DOM and HTML related behavior. It's a giant leap forward, but frankly I've been using something better for years.

    Posted by Frans (external link) on Thu 26 Mar 2009 at 19:49

  • (external link)

    And this one (from the same source as the quote) also shows an IE8 bug quite nicely. IE8 may claim support for more properties or something, although buggy support should NOT count as support at all imo.

    Also there is something that both Webkit and IE8 do on my weblog, which if you ask me is buggy, but I'll have to look into creating a minimized testcase for that. Or I could be wrong which would make Opera and Firefox buggy on that one...

    Anyway, I haven't really followed IE8's release, but if Microsoft is claiming that they fully support CSS2.1 then that's the same kind of nonsense as Apple's claimed support for ARIA in Safari.

    Posted by Frans (external link) on Thu 26 Mar 2009 at 19:57