In keeping with its ongoing aim to not "break the Web" with major changes to the Internet Explorer (IE) rendering engine, Microsoft this week revealed how it will handle its support of Web standards in the next version of the Web browser. IE 8 will sport three different compatibility modes, up from two in IE 7, one of which will more firmly conform to modern Web standards.

There's just one problem: This new more rigid standards mode won't be enabled by default because, Microsoft says, enabling it will break compatibility with too much of the existing Web. According to Chris Wilson, an IE platform architect, there are half a billion IE users and "billions" of pages on the Web today that already work in IE 6 and IE 7. Supporting incompatible standards in IE 8 would therefore be a mistake, he says.

Microsoft's "Don't break the Web" approach is a natural offshoot of the company's longstanding plans to break customer compatibility as little as possible during product upgrades. But in this case, there are concerns in the developer community that Microsoft is being far too conservative. The company's approach to compatibility in IE 8 appears to be quite complex, with the most rigid standards mode requiring developers to add certain tags to their Web site pages so that the upcoming browser will render accordingly.

The end result is this tiered support of Web standards. IE 8 will support "quirks mode," which allows the browser to render like IE 6 and previous IE versions, "standards mode," which is based on IE 7, and the new more rigid standards mode. This latter option will require developers to modify their pages to support it.

As for the schedule for IE 8, we're still waiting for details. Microsoft is expected to ship at least a beta version of IE 8 in the first half of 2008, but the final release is unknown.