CSS3 Selectors enable complex styling of webpages using simpler CSS and less script than previously possible. “As we demoed back in November, and updated in March and May with IE9 Platform Preview Builds, IE9 includes full support for CSS3 selectors: E:root, E:nth-child(n), E:nth-last-child(n), E:nth-of-type(n), E:nth-last-of-type(n), E:last-child, E:first-of-type, E:last-of-type, E:only-child, E:only-of-type, E:only-child, E:only-of-type E:empty, E:target, E:enabled, E:disabled, E:checked, E:indeterminate, E:not(s), ::selection. Our goal is to enable new selectors in your webpages in a way that lets the same markup work across browsers. A nice side effect of this work is better results in test suites that measure selectors support. IE9 now passes 100% of test cases on css3.info, 100% of the W3C CSS3 Selectors Test Suite, and Acid3 tests 34 through 37 and 39 through 44,” writes IE team.