When can I safely use the new element in HTML5?

Question

On the 16th December, a HTML5 extension specification for the

element was submitted to the W3C under something called an editors draft. The abstract is

Answer 1

You can go ahead and use it, Chrome 26 and Firefox 21 already implemented it.

Just as with the introduction of many other new HTML5 elements, not all browsers recognise

or have preset styles for it. You’ll need to ensure it displays as a block level element in your CSS:

main {display:block;}

For the time being, you'll also need to use JavaScript to create the element for older versions of IE:

Of course, if you use the html5shiv,

is now baked in directly.