From Aaron Gustafson at A List Apart…

“Building on the momentum created by the release of Internet Explorer 7, which included major advances in CSS support, the IE team began work on a completely new rendering engine for IE8—one that followed the CSS 2.1 spec as closely as possible. The culmination of their efforts is a browser capable of rendering the Acid2 test accurately. For those of you keeping track, this means that IE will soon support generated content and data URLs, and, it has been confirmed, will banish hasLayout forever. This will put its rendering on par with other browsers that have passed Acid2, including Safari, iCab, Konqueror, and Opera. (Firefox 3, which passes Acid2, had not been released as of this writing.)”

In an effort to avoid the same issues Microsoft encountered with the release of IE7 (sites designed specifically for IE6 ‘breaking’ when viewed in IE7), the IE8 team has collaborated with various web standards advocacy groups to support a meta tag that essentially dictates to the browser what “browser version” the page should be rendered in. By default, IE8 rendering will be nearly identical to IE7, but in order to view the page in the new “web standards” mode, developers will have to include the meta tag in the head of their pages. The code is supposedly simple enough that other browser makers will be able follow suit and add support for it as well, though from a developers perspective this looks to be a symptom of Microsoft trying to clean up the mess it made with IE6 rather than any attempt to push the web standards envelope.