queue.js

var Queue = function(){
    var deferArray = [],
        running = false;

    function recursiveExecute(done) {
        // maintain scope
        (function recurse(){
            if (running && deferArray.length) {
                var func = deferArray.shift();
                
                // continue on the next event loop iteration
                setTimeout(function(){ 
                    func(recurse); 
                }, 0);
            } else {
                if (done && (typeof done === 'function')) {
                    done();   
                }   
            }
        })();
    }

    this.push = function(func) {
        deferArray.push(function(cb){
            func();
            cb();
        });  
    };

    this.run = function(done){
        running = true;
        recursiveExecute(done);
    };

    this.stop = function(){
        running = false;
    };
};