The source code

    (function(){

    var libFlyweight,
        version = Prototype.Version.split('.'),
        mouseEnterSupported = (parseInt(version[0]) >= 2) || (parseInt(version[1]) >= 7) || (parseInt(version[2]) >= 1),
        mouseCache = {},
        isXUL = Ext.isGecko ? function(node){
            return Object.prototype.toString.call(node) == '[object XULElement]';
        } : function(){},
        isTextNode = Ext.isGecko ? function(node){
            try{
                return node.nodeType == 3;
            }catch(e) {
                return false;
            }

        } : function(node){
            return node.nodeType == 3;
        },
        elContains = function(parent, child) {
           if(parent && parent.firstChild){
             while(child) {
                if(child === parent) {
                    return true;
                }
                try {
                    child = child.parentNode;
                } catch(e) {
                    // In FF if you mouseout an text input element
                    // thats inside a div sometimes it randomly throws
                    // Permission denied to get property HTMLDivElement.parentNode
                    // See https://bugzilla.mozilla.org/show_bug.cgi?id=208427
                    return false;
                }
                if(child && (child.nodeType != 1)) {
                    child = null;
                }
              }
            }
            return false;
        },
        checkRelatedTarget = function(e) {
            var related = Ext.lib.Event.getRelatedTarget(e);
            return !(isXUL(related) || elContains(e.currentTarget,related));
        };

    Ext.lib.Dom = {
        getViewWidth : function(full){
            return full ? this.getDocumentWidth() : this.getViewportWidth();
        },

        getViewHeight : function(full){
            return full ? this.getDocumentHeight() : this.getViewportHeight();
        },

        getDocumentHeight: function() { // missing from prototype?
            var scrollHeight = (document.compatMode != "CSS1Compat") ? document.body.scrollHeight : document.documentElement.scrollHeight;
            return Math.max(scrollHeight, this.getViewportHeight());
        },

        getDocumentWidth: function() { // missing from prototype?
            var scrollWidth = (document.compatMode != "CSS1Compat") ? document.body.scrollWidth : document.documentElement.scrollWidth;
            return Math.max(scrollWidth, this.getViewportWidth());
        },

        getViewportHeight: function() { // missing from prototype?
            var height = self.innerHeight;
            var mode = document.compatMode;

            if ( (mode || Ext.isIE) && !Ext.isOpera ) {
                height = (mode == "CSS1Compat") ?
                        document.documentElement.clientHeight : // Standards
                        document.body.clientHeight; // Quirks
            }

            return height;
        },

        getViewportWidth: function() { // missing from prototype?
            var width = self.innerWidth;  // Safari
            var mode = document.compatMode;

            if (mode || Ext.isIE) { // IE, Gecko, Opera
                width = (mode == "CSS1Compat") ?
                        document.documentElement.clientWidth : // Standards
                        document.body.clientWidth; // Quirks
            }
            return width;
        },

        isAncestor : function(p, c){ // missing from prototype?
            p = Ext.getDom(p);
            c = Ext.getDom(c);
            if (!p || !c) {return false;}

            if(p.contains && !Ext.isSafari) {
                return p.contains(c);
            }else if(p.compareDocumentPosition) {
                return !!(p.compareDocumentPosition(c) & 16);
            }else{
                var parent = c.parentNode;
                while (parent) {
                    if (parent == p) {
                        return true;
                    }
                    else if (!parent.tagName || parent.tagName.toUpperCase() == "HTML") {
                        return false;
                    }
                    parent = parent.parentNode;
                }
                return false;
            }
        },

        getRegion : function(el){
            return Ext.lib.Region.getRegion(el);
        },

        getY : function(el){
            return this.getXY(el)[1];
        },

        getX : function(el){
            return this.getXY(el)[0];
        },

        getXY : function(el){ // this initially used Position.cumulativeOffset but it is not accurate enough
            var p, pe, b, scroll, bd = (document.body || document.documentElement);
            el = Ext.getDom(el);

            if(el == bd){
                return [0, 0];
            }

            if (el.getBoundingClientRect) {
                b = el.getBoundingClientRect();
                scroll = fly(document).getScroll();
                return [Math.round(b.left + scroll.left), Math.round(b.top + scroll.top)];
            }
            var x = 0, y = 0;

            p = el;

            var hasAbsolute = fly(el).getStyle("position") == "absolute";

            while (p) {

                x += p.offsetLeft;
                y += p.offsetTop;

                if (!hasAbsolute && fly(p).getStyle("position") == "absolute") {
                    hasAbsolute = true;
                }

                if (Ext.isGecko) {
                    pe = fly(p);

                    var bt = parseInt(pe.getStyle("borderTopWidth"), 10) || 0;
                    var bl = parseInt(pe.getStyle("borderLeftWidth"), 10) || 0;

                    x += bl;
                    y += bt;

                    if (p != el && pe.getStyle('overflow') != 'visible') {
                        x += bl;
                        y += bt;
                    }
                }
                p = p.offsetParent;
            }

            if (Ext.isSafari && hasAbsolute) {
                x -= bd.offsetLeft;
                y -= bd.offsetTop;
            }

            if (Ext.isGecko && !hasAbsolute) {
                var dbd = fly(bd);
                x += parseInt(dbd.getStyle("borderLeftWidth"), 10) || 0;
                y += parseInt(dbd.getStyle("borderTopWidth"), 10) || 0;
            }

            p = el.parentNode;
            while (p && p != bd) {
                if (!Ext.isOpera || (p.tagName != 'TR' && fly(p).getStyle("display") != "inline")) {
                    x -= p.scrollLeft;
                    y -= p.scrollTop;
                }
                p = p.parentNode;
            }
            return [x, y];
        },

        setXY : function(el, xy){ // this initially used Position.cumulativeOffset but it is not accurate enough
            el = Ext.fly(el, '_setXY');
            el.position();
            var pts = el.translatePoints(xy);
            if(xy[0] !== false){
                el.dom.style.left = pts.left + "px";
            }
            if(xy[1] !== false){
                el.dom.style.top = pts.top + "px";
            }
        },

        setX : function(el, x){
            this.setXY(el, [x, false]);
        },

        setY : function(el, y){
            this.setXY(el, [false, y]);
        }
    };

    Ext.lib.Event = {
        getPageX : function(e){
            return Event.pointerX(e.browserEvent || e);
        },

        getPageY : function(e){
            return Event.pointerY(e.browserEvent || e);
        },

        getXY : function(e){
            e = e.browserEvent || e;
            return [Event.pointerX(e), Event.pointerY(e)];
        },

        getTarget : function(e){
            return Event.element(e.browserEvent || e);
        },

        resolveTextNode: function(node) {
            return node && !isXUL(node) && isTextNode(node) ? node.parentNode : node;
        },

        getRelatedTarget: function(ev) { // missing from prototype?
            ev = ev.browserEvent || ev;
            var t = ev.relatedTarget;
            if (!t) {
                if (ev.type == "mouseout") {
                    t = ev.toElement;
                } else if (ev.type == "mouseover") {
                    t = ev.fromElement;
                }
            }

            return this.resolveTextNode(t);
        },

        on : function(el, eventName, fn){
            if((eventName == 'mouseenter' || eventName == 'mouseleave') && !mouseEnterSupported){
                var item = mouseCache[el.id] || (mouseCache[el.id] = {});
                item[eventName] = fn;
                fn = fn.createInterceptor(checkRelatedTarget);
                eventName = (eventName == 'mouseenter') ? 'mouseover' : 'mouseout';
            }
            Event.observe(el, eventName, fn, false);
        },

        un : function(el, eventName, fn){
            if((eventName == 'mouseenter' || eventName == 'mouseleave') && !mouseEnterSupported){
                var item = mouseCache[el.id],
                    ev = item && item[eventName];

                if(ev){
                    fn = ev.fn;
                    delete item[eventName];
                    eventName = (eventName == 'mouseenter') ? 'mouseover' : 'mouseout';
                }
            }
            Event.stopObserving(el, eventName, fn, false);
        },

        purgeElement : function(el){
            // no equiv?
        },

        preventDefault : function(e){   // missing from prototype?
            e = e.browserEvent || e;
            if(e.preventDefault) {
                e.preventDefault();
            } else {
                e.returnValue = false;
            }
        },

        stopPropagation : function(e){   // missing from prototype?
            e = e.browserEvent || e;
            if(e.stopPropagation) {
                e.stopPropagation();
            } else {
                e.cancelBubble = true;
            }
        },

        stopEvent : function(e){
            Event.stop(e.browserEvent || e);
        },

        onAvailable : function(id, fn, scope){  // no equiv
            var start = new Date(), iid;
            var f = function(){
                if(start.getElapsed() > 10000){
                    clearInterval(iid);
                }
                var el = document.getElementById(id);
                if(el){
                    clearInterval(iid);
                    fn.call(scope||window, el);
                }
            };
            iid = setInterval(f, 50);
        }
    };

    Ext.lib.Ajax = function(){
        var createSuccess = function(cb){
             return cb.success ? function(xhr){
                cb.success.call(cb.scope||window, {
                    responseText: xhr.responseText,
                    responseXML : xhr.responseXML,
                    argument: cb.argument
                });
             } : Ext.emptyFn;
        };
        var createFailure = function(cb){
             return cb.failure ? function(xhr){
                cb.failure.call(cb.scope||window, {
                    responseText: xhr.responseText,
                    responseXML : xhr.responseXML,
                    argument: cb.argument
                });
             } : Ext.emptyFn;
        };
        return {
            request : function(method, uri, cb, data, options){
                var o = {
                    method: method,
                    parameters: data || '',
                    timeout: cb.timeout,
                    onSuccess: createSuccess(cb),
                    onFailure: createFailure(cb)
                };
                if(options){
                    var hs = options.headers;
                    if(hs){
                        o.requestHeaders = hs;
                    }
                    if(options.xmlData){
                        method = (method ? method : (options.method ? options.method : 'POST'));
                        if (!hs || !hs['Content-Type']){
                            o.contentType = 'text/xml';
                        }
                        o.postBody = options.xmlData;
                        delete o.parameters;
                    }
                    if(options.jsonData){
                        method = (method ? method : (options.method ? options.method : 'POST'));
                        if (!hs || !hs['Content-Type']){
                            o.contentType = 'application/json';
                        }
                        o.postBody = typeof options.jsonData == 'object' ? Ext.encode(options.jsonData) : options.jsonData;
                        delete o.parameters;
                    }
                }
                new Ajax.Request(uri, o);
            },

            formRequest : function(form, uri, cb, data, isUpload, sslUri){
                new Ajax.Request(uri, {
                    method: Ext.getDom(form).method ||'POST',
                    parameters: Form.serialize(form)+(data?'&'+data:''),
                    timeout: cb.timeout,
                    onSuccess: createSuccess(cb),
                    onFailure: createFailure(cb)
                });
            },

            isCallInProgress : function(trans){
                return false;
            },

            abort : function(trans){
                return false;
            },

            serializeForm : function(form){
                return Form.serialize(form.dom||form);
            }
        };
    }();

    Ext.lib.Anim = function(){

        var easings = {
            easeOut: function(pos) {
                return 1-Math.pow(1-pos,2);
            },
            easeIn: function(pos) {
                return 1-Math.pow(1-pos,2);
            }
        };
        var createAnim = function(cb, scope){
            return {
                stop : function(skipToLast){
                    this.effect.cancel();
                },

                isAnimated : function(){
                    return this.effect.state == 'running';
                },

                proxyCallback : function(){
                    Ext.callback(cb, scope);
                }
            };
        };
        return {
            scroll : function(el, args, duration, easing, cb, scope){
                // not supported so scroll immediately?
                var anim = createAnim(cb, scope);
                el = Ext.getDom(el);
                if(typeof args.scroll.to[0] == 'number'){
                    el.scrollLeft = args.scroll.to[0];
                }
                if(typeof args.scroll.to[1] == 'number'){
                    el.scrollTop = args.scroll.to[1];
                }
                anim.proxyCallback();
                return anim;
            },

            motion : function(el, args, duration, easing, cb, scope){
                return this.run(el, args, duration, easing, cb, scope);
            },

            color : function(el, args, duration, easing, cb, scope){
                return this.run(el, args, duration, easing, cb, scope);
            },

            run : function(el, args, duration, easing, cb, scope, type){
                var o = {};
                for(var k in args){
                    switch(k){   // scriptaculous doesn't support, so convert these
                        case 'points':
                            var by, pts, e = Ext.fly(el, '_animrun');
                            e.position();
                            if(by = args.points.by){
                                var xy = e.getXY();
                                pts = e.translatePoints([xy[0]+by[0], xy[1]+by[1]]);
                            }else{
                                pts = e.translatePoints(args.points.to);
                            }
                            o.left = pts.left+'px';
                            o.top = pts.top+'px';
                        break;
                        case 'width':
                            o.width = args.width.to+'px';
                        break;
                        case 'height':
                            o.height = args.height.to+'px';
                        break;
                        case 'opacity':
                            o.opacity = String(args.opacity.to);
                        break;
                        default:
                            o[k] = String(args[k].to);
                        break;
                    }
                }
                var anim = createAnim(cb, scope);
                anim.effect = new Effect.Morph(Ext.id(el), {
                    duration: duration,
                    afterFinish: anim.proxyCallback,
                    transition: easings[easing] || Effect.Transitions.linear,
                    style: o
                });
                return anim;
            }
        };
    }();

    // all lib flyweight calls use their own flyweight to prevent collisions with developer flyweights
    function fly(el){
        if(!libFlyweight){
            libFlyweight = new Ext.Element.Flyweight();
        }
        libFlyweight.dom = el;
        return libFlyweight;
    }

    Ext.lib.Region = function(t, r, b, l) {
        this.top = t;
        this[1] = t;
        this.right = r;
        this.bottom = b;
        this.left = l;
        this[0] = l;
    };

    Ext.lib.Region.prototype = {
        contains : function(region) {
            return ( region.left   >= this.left   &&
                     region.right  <= this.right  &&
                     region.top    >= this.top    &&
                     region.bottom <= this.bottom    );

        },

        getArea : function() {
            return ( (this.bottom - this.top) * (this.right - this.left) );
        },

        intersect : function(region) {
            var t = Math.max( this.top,    region.top    );
            var r = Math.min( this.right,  region.right  );
            var b = Math.min( this.bottom, region.bottom );
            var l = Math.max( this.left,   region.left   );

            if (b >= t && r >= l) {
                return new Ext.lib.Region(t, r, b, l);
            } else {
                return null;
            }
        },
        union : function(region) {
            var t = Math.min( this.top,    region.top    );
            var r = Math.max( this.right,  region.right  );
            var b = Math.max( this.bottom, region.bottom );
            var l = Math.min( this.left,   region.left   );

            return new Ext.lib.Region(t, r, b, l);
        },

        constrainTo : function(r) {
                this.top = this.top.constrain(r.top, r.bottom);
                this.bottom = this.bottom.constrain(r.top, r.bottom);
                this.left = this.left.constrain(r.left, r.right);
                this.right = this.right.constrain(r.left, r.right);
                return this;
        },

        adjust : function(t, l, b, r){
            this.top += t;
            this.left += l;
            this.right += r;
            this.bottom += b;
            return this;
        }
    };

    Ext.lib.Region.getRegion = function(el) {
        var p = Ext.lib.Dom.getXY(el);

        var t = p[1];
        var r = p[0] + el.offsetWidth;
        var b = p[1] + el.offsetHeight;
        var l = p[0];

        return new Ext.lib.Region(t, r, b, l);
    };

    Ext.lib.Point = function(x, y) {
       if (Ext.isArray(x)) {
          y = x[1];
          x = x[0];
       }
        this.x = this.right = this.left = this[0] = x;
        this.y = this.top = this.bottom = this[1] = y;
    };

    Ext.lib.Point.prototype = new Ext.lib.Region();

    // prevent IE leaks
    if(Ext.isIE) {
        function fnCleanUp() {
            var p = Function.prototype;
            delete p.createSequence;
            delete p.defer;
            delete p.createDelegate;
            delete p.createCallback;
            delete p.createInterceptor;

            window.detachEvent("onunload", fnCleanUp);
        }
        window.attachEvent("onunload", fnCleanUp);
    }
    })();