Immediately invoked function expressions

gistfile1.js

// http://speakerdeck.com/u/addyosmani/p/large-scale-javascript-application-architecture

(function(){
     // code to be immediately invoked
}()); // Crockford recommend this way

(function(){
     // code to be immediately invoked
})(); // This is just as valid

(function(window, document, undefined){
     // code to be immediately invoked
})(this, this.document);

(function(global, undefined){
     // code to be immediately invoked
})(this);