"We've decided that IE8 will, by default, interpret web content in the most standards compliant way it can. This decision is a change from what we've posted previously. Microsoft recently published a set of Interoperability Principles. Thinking about IE8's behavior with these principles in mind, interpreting web content in the most standards compliant way possible is a better thing to do. We think that acting in accordance with principles is important, and IE8's default is a demonstration of the interoperability principles in action. While we do not believe any current legal requirements would dictate which rendering mode a browser must use, this step clearly removes this question as a potential legal and regulatory issue. As stated above, we think it's the better choice." Ars has more.