ol reverse attribute polyfill

a.js

//a polyfill for the ordered-list reversed attribute
// http://www.whatwg.org/specs/web-apps/current-work/multipage/grouping-content.html#the-ol-element
// http://www.whatwg.org/specs/web-apps/current-work/multipage/grouping-content.html#dom-li-value

//uses these awesomeness:
// Array.prototype.forEach
// Element.prototype.children
//if you want support for older browsers *cough*IE8-*cough*, then use the other
// file provided
(function () {
"use strict";

	if ( 'reversed' in document.createElement('ol') ) {
		return;
	}

	[].forEach.call( document.getElementsByTagName('ol'), function ( list ) {
		if ( list.getAttribute( 'reversed' ) !== null ) {
			reverseList( list );
		}
	});

	function reverseList ( list ) {
		var children = list.children, count = list.getAttribute('start');

		//check to see if a start attribute is provided
		if ( count !== null ) {
			count = Number( count );

			if ( isNaN(count) ) {
				count = null;
			}
		}

		//no, this isn't duplication - start will be set to null
		// in the previous if statement if an invalid start attribute
		// is provided
		if ( count === null ) {
			count = children.length;
		}

		[].forEach.call( children, function ( child ) {
			child.value = count--;
		});
	}
}());

b.js

//use this if you want support for browsers which don't have ES5 goodies
(function () {
	if ( 'reversed' in document.createElement('ol') ) {
		return;
	}

	var lists = document.getElementsByTagName( 'ol' );

	for ( var i = 0, len = lists.length; i < len; i++ ) {
		if ( lists[i].getAttribute( 'reversed' ) !== null ) {
			reverseList( lists[i] );
		 }
	}

	function reverseList ( list ) {
		var children = [], childNodes = list.childNodes,
			count = list.getAttribute('start'), i, len;

		for ( i = 0, len = childNodes.length; i < len; i++ ) {
                        //Node.ELEMENT_NODE === 1
			if ( childNodes[i].nodeType === 1 ) {
				children.push( childNodes[i] );
			}
		}

		//check to see if a start attribute is provided
		if ( count !== null ) {
			count = Number( count );

			if ( isNaN(count) ) {
				count = null;
			}
		}

		//no, this isn't duplication - start will be set to null
		// in the previous if statement if an invalid start attribute
		// is provided
		if ( count === null ) {
			count = children.length;
		}

		for ( i = 0, len = children.length; i < len; i++ ) {
			children[ i ].value = count--;
		}
	}
}());

I added support for li value attributes: https://gist.github.com/1896721

What's the license for these code snippets?