Parses a user agent string to detect Internet Explorer.
A bare-bones minimal way of detecting IE6, IE7 or IE8.
<?php
use webignition\IEDetector\IEDetector;
$ie6UserAgent = 'Mozilla/4.0 (MSIE 6.0; Windows NT 5.0)';
if (UserAgentDetector::isIE6()) {
// ...
}