Now that the numbers for IE6 and IE7 usage are diminishing rapidly, more and more development teams are starting to weed out support for those older browsers.
Most readers will probably have removed IE6 completely from the equation and soon IE7 will follow. Despite IE8 still having the highest share of any single browser version, the demise of IE6/7 now allows us to be more creative with CSS selectors.
This post will provide a comprehensive review of support for CSS3 selectors in the most troublesome browsers (guess which ones?). Each selector links to the appropriate location in the CSS3 spec.