JavaScript. Patterns.

// Namespace
// Global Object
var MYAPP = {};
// Constructors
MYAPP.Foo = function () {};
MYAPP.Bar = function () {};
// Variable
MYAPP.baz = 'foo';
// Container Object
MYAPP.modules = {};
// Submodules
MYAPP.modules.module1 = {};

// Dependencies
var myFunction = function () {
  var event = YAHOO.util.Event,
      dom = YAHOO.util.Dom;
  
  // use event, dom ...
};

//myFunction(); // Uncaught ReferenceError: YAHOO is not defined

// Public and Private methods
function Foo() {
  var bar = 'baz';
  this.getBar = function() {
    return bar;
  };
}

//console.log((new Foo()).getBar()); // baz
//console.log((new Foo()).bar); // undefined

var Foo = (function () {
  // Private attribute
  var bar = 'baz';
  // Private method
  var boo = function () {
    return 'boo';
  };
  return {
    // Public (Privileged) method
    getBar: function () {
      return boo() + bar;
    }
  };
})();

console.log(Foo.getBar()); // boobaz
console.log(Foo.bar); // undefined
//Foo.boo(); // Uncaught TypeError: Foo.boo is not a function

// Private methods and Prototypes

function MyFoo() {
  var bar = 'bar';
  this.getBar = function () {
    return bar;
  };
}

MyFoo.prototype = (function () {
  var baz = 'baz';
  return {
    getBaz: function () {
      return baz;
    }
  };
})();

var myFoo = new MyFoo();
console.log(myFoo.getBar()); // bar
console.log(myFoo.getBaz()); // baz