Playing with :nth children

Two fun visual playgrounds to help understand the advanced usage of nth-child:

• http://nthmaster.com/
• http://lea.verou.me/demos/nth.html

for a great explanation of how it works, start with Chris Coyiers article http://css-tricks.com/how-nth-child-works/.
where Chris has his own visual tester linked at the end of the article.

But of course, IE is late to the game on this, with no support until IE9!
For IE 6-8 (as long as we need to consider them *sigh) we can use Selectivizr