I need to start this post with a giant asterisk: I’ve barely done any regression testing yet. With the exception of one regression a commenter found, my initial results assume that IE 8 doesn’t have any standards support bugs that weren’t in IE 7. This is a big assumption, since IE’s CSS engine was largely (perhaps entirely) rewritten for IE 8. I expect IE 8 to have a number of new bugs which aren’t yet documented in my tables, and those bugs will be discovered and documented over time.
Alright, now that that’s out of the way, let’s get to the current results. IE 8 has fixed almost every single CSS 2.1 compliance bug from IE 7. I’m currently counting a total of 17 “Incomplete” values (7 of which are due to the single regression mentioned above), with everything else being a “Y”.
This is a huge deal. While I can’t yet comment on the CSS 3, HTML, or DOM support, IE 8’s CSS 2.1 support is now right up with the competition. We still have to see how it holds up after more regressions are found, but it is currently ranking as the #1 most CSS 2.1-compliant web browser I’ve tested. This is truly excellent work from the IE team.
In the next version of IE, I would like to see some focus on getting rid of a number of “temporary glitches” I’ve noticed. They appear to be similar to the reflow bugs that plagued Firefox 2, in that merely hovering your mouse over the element or interacting with stuff around the element will often correct the glitch. An example is the tabs in the Webpage test system. I don’t think there’s any neat little box in my tables where I can document these issues; they seem more related to IE just losing track of stuff during painting.
I’m going to do the CSS 3 testing next.