Determine the prefix of the browser: o, moz, webkit, ms

prefix.js

/*jslint devel: false, browser: true, sloppy: true, maxerr: 50, indent: 4 */

//
// `PREFIX` variable will most likely be one of the following:
//  [o, moz, ms, webkit]
//

var PREFIX = (function (window, document) {

// Get computed styles from the document to assess names of the CSS properties

	var styles = window.getComputedStyle(document.documentElement, null),
		i,
		l,
		style,
		prefix,

// A register to keep track of the count of most common prefix

		highest = 0,

// The most common prefix

		result,

// prefixes = {} works here too

		prefixes = Object.create(null);

	for (i = 0, l = styles.length; i < l; i += 1) {

// Run through each CSS property and determine its prefix which is assumed to have
// the format: -prefix-css-property

		style = styles[i] || '';
		prefix = style.split('-')[1];

		if (prefix) {
			if (!prefixes[prefix]) {
				prefixes[prefix] = 0;
			}

			prefixes[prefix] += 1;

			if (highest < prefixes[prefix]) {
				highest = prefixes[prefix];
				result = prefix;
			}
		}
	}

	return result;
}(window, window.document));