Can we share variables between js instances and patches ?

You can implement an own event system - if you want. The idea is that you can assign any function to an event (== eventListener), and you can fire this event from anywhere. If you fire an event some data that you sent to the event will be passed to the listener-functions and the function will be executed.

here is how i implemented it on my local machine.

1. you need to add a file with this code to the [...]Cycling '74Max 6.0Cycling '74jsextensions folder (to be loaded automatically on Max startup):

var jm = {};
jm.event = jm.event || function() {
    var _events = {};
    var addListener = function(data) {
        if(_events[data.eventName] == undefined) {
            _events[data.eventName] = [];
        }
        _events[data.eventName].push(data.eventListener);
    };
    var fire = function(eventInfo) {
        if(_events[eventInfo.eventName] != undefined ) {
        for(i=0; i

than you can add an eventListeners and fire events from any js object like this:

var firstListener = function (jmEvent) {
    post("firstListener -- ")
    post("eventName is :"+jmEvent.eventName);
    post(" eventData is :"+jmEvent.eventData +"n");

}
jm.event.addListener(
    {
    eventName: "myEvent",
    eventListener : firstListener
    }
);

var fire = function (newVal) {
    post("fire called");
    jm.event.fire(
        {
        eventName : "myEvent",
        eventData : newVal
        }
    );
}

attached is an example patch and the .js files (jm.event.js goes into the jsextensions folder before you start Max).
Jan