observable.js

var Observable = (function(){
	function O(initial) {
		this._value = initial;
		this._callbacks = [];

		return this;
	}

	O.prototype = {
		get: function() { return this.value; },
		set: function(value) { this._value = value; this.triggerChange(); },
		listen: function(handler) { this._callbacks.push(handler); },
		triggerChange: function() {
			for (var i = this._callbacks.length - 1; i >= 0; i--) {
				this._callbacks[i](this._value);
			}
		}
	}

	return O;
})()

hmmmmm I dunno bro