In its last few releases, Internet Explorer (IE) has focused primarily on addressing the various security issues that have plagued it for years. But IE8 promises to be different. In IE8, the majority of new features will take aim at cross-browser compatibility and at improving Internet Explorer's adherence to Web standards. Although IE8 is still in beta testing, some of these changes may pose compatibility problems with a shop's existing Web applications.
The source of these compatibility issues: numerous standards that are supposed to be supported uniformly by all Web browsers but that no one enforces. As a result, two different browsers might render the same Web page in two different ways because the creators of these browsers apply standards as they see fit rather than following standards to the letter.
Not following a standard doesn't always mean that important parts of a standard are omitted, however. In many cases, the standards may be augmented so that a browser will support commands in ways in which they were never intended to be used (at least not according to the standards).
Internet Explorer 8 will be the first version of Internet Explorer with a strict standpoint on Web standards compliance. So, for example, if an existing Web application was designed to rely on features or "quirks" of Internet Explorer that are not part of the underlying Web standards, it's likely that the Web application won't work correctly.
This raises two questions: Which Internet Explorer features will be affected by this new standardization, and second, what happens if a Web application depends heavily on something that is no longer going to be supported?
To answer the first question, according to the Microsoft website, the browser inconsistencies addressed so far include separate URL handling for attributes and the Get, Set and Remove attribute implementations, which have been made compatible with other browsers. Further, IE8 supports default HTML attributes so that HTML attributes always exist, even if they are not applied explicitly to an element.
To answer the second question, IE8 remains in beta testing, and even when it is finally released, it will probably take some time for it to become widely adopted. So you've still got time to modify your Web application.
Also, although IE8 will run in Standards mode by default, it can also run in a couple of backward-compatibility modes to display otherwise incompatible Web pages. One is Strict mode, which is designed to make IE8 behave like IE7. The other is Quirks mode, and it can be used to make IE8 support the same kinds of features as IE5 and other legacy browsers.
I believe that it is a huge mistake to leave incompatible Web applications in their current form and expect site visitors to work in Strict mode. For one, many of the site's visitors probably won't know how to use Strict mode or won't want to be bothered with switching browser modes. Another reason for adapting your site now is that while IE8 will include a feature that makes it backward-compatible with IE7, IE9 may not include this feature.
About the author: Brien M. Posey, MCSE, has received Microsoft's Most Valuable Professional Award four times for his work with Windows Server, IIS and Exchange Server. He has served as CIO for a nationwide chain of hospitals and healthcare facilities, and was once a network administrator for Fort Knox.
This was first published in August 2008