Today started out as a normal day and ended up as being one of the most interesting days in the history of web development.

First, Microsoft announced a change in the way Internet Explorer 8 will work. Instead of defaulting to IE7′s rendering mode and forcing developers to opt-in to the “super standards” mode, IE8 will now be in super standards mode by default and developers can opt-out to the IE7 rendering mode. This is huge news and somewhat surprising given Microsoft’s earlier announcement of how IE8 would work.

Unlike a lot of people, I really didn’t have a problem with the original proposal, and I also don’t have a problem with this one. I think both show that Microsoft is listening to web developers and is really trying to do the right thing.

The second thing that happened is the release of the Acid3 Test. Unlike previous versions, which tested only CSS compliance, the Acid3 test looks at both CSS and JavaScript behavior in browsers. It looks at DOM Level 2 compliance, CSS 2 and 3, XHTML, and more. This is the next big step in standards compliance for browsers and provides a great tool for all companies to use. It’ll be interesting to see which browser wins the Acid3 race.