Avoid `console` errors in browsers that lack a console.

footer.html

        <!--[if lte IE 9]>
        <script>
            // Avoid `console` errors in browsers that lack a console.
            (function() {
                var method;
                var noop = function () {};
                var methods = [
                    'assert', 'clear', 'count', 'debug', 'dir', 'dirxml', 'error',
                    'exception', 'group', 'groupCollapsed', 'groupEnd', 'info', 'log',
                    'markTimeline', 'profile', 'profileEnd', 'table', 'time', 'timeEnd',
                    'timeline', 'timelineEnd', 'timeStamp', 'trace', 'warn'
                ];
                var length = methods.length;
                var console = (window.console = window.console || {});
            
                while (length--) {
                    method = methods[length];
            
                    // Only stub undefined methods.
                    if (!console[method]) {
                        console[method] = noop;
                    }
                }
            }());
        </script>
        <![endif]-->
        <script src="//ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
        <script src="js/vendor.js"></script>
        <script src="js/app.js"></script>
    </body>
</html>

https://github.com/h5bp/html5-boilerplate/blob/master/dist/js/plugins.js