tacet.js

tacet = {
    create: (function () {
        function F() {}

        return function (proto) {
            F.prototype = proto;
            return new F();
        };
    }),

    XMLHttpRequest: (function () {
        var options = [
            function () { return new XMLHttpRequest() },
            function () { return new ActiveXObject("Microsoft.XMLHTTP") },
            function () { return new ActiveXObject("Msxml2.XMLHTTP.6.0") }
        ];

        for (var i = 0, il = options.length; i < il; i++) {
            try { return options[i]() } catch(e) {}
        }
    })
};