Set browser forking classes on the html element

jQuery.browser-fork.js

/*
	Set browser forking classes on html element. Can be executed as soon as jQuery is loaded.
	@dependency jQuery 1.4
	flags are: webkit, opera, msie, mozilla, (safari flag not used), os-win, os-mac
*/
(function(flags, app) {
	$.each($.browser, function(k, v) { 
		if (v === true && k !== 'safari') flags.push(k);
	});
	os('Win', 'os-win');
	os('Mac', 'os-mac');
	os('NT 5.1', 'os-xp');
	os('NT 6.0', 'os-vista');
	os('NT 6.1', 'os-win7');
	window.browserFlags = $('html').addClass(flags.join(' ')).attr('class');
	
	function os (s, f) { if (app.indexOf(s) !== -1) flags.push(f); }

})([], String(navigator && navigator.appVersion));

Updated to include os forking.

Updated to include various versions of Windows.