Browser manufacturers have already started rolling out support for many of the new features even if they aren’t yet set in stone. Opera and Safari have been leading the way when it comes to CSS 3 features, but Firefox 3 packs in a few and 3.1 promises to bring Firefox alongside the others. Users of Internet Explorer are out of luck. Although, there’s no reason you can’t use some rounded corner properties solely for your Firefox/Opera/Safari visitors. IE will still render the backgrounds as usual, it just won’t understand the rounded corner bit.