Browsers and standards
Opera 9 Safari 2.0 Konqueror 3.5 Firefox 2 Internet Explorer 7 Those are the results of running the Acid2 test against the most popular browsers.
The results are eloquent, but just in case, I'm going to clarify it: it should be a yellow smiley face over a white background that when you pass the mouse over or near the nose, it becomes blue.
Opera 9 passes the Acid 2 test, making it the second browser to do so, and the first browser for Windows or Linux/UNIX to pass.