Compiled CoffeeScript from https://gist.github.com/4085837

gistfile1.js

var Foo, singletonFoo;

Foo = (function() {
  var _this = this;

  function Foo() {}

  Foo.instance = (function() {
    var instance;
    instance = null;
    return function() {
      if (!instance) {
        instance = new Foo();
      }
      return instance;
    };
  })();

  return Foo;

}).call(this);

singletonFoo = Foo.instance();