UMD boilerplate to handle AMD, Commonjs, and standard browser js

umd.js

// Example UMD wrapper for a module that takes dependencies on underscore and postal.js
(function ( root, factory ) {
  if ( typeof module === "object" && module.exports ) {
		// Node, or CommonJS-Like environments
		// Intentionally returning a factory method
		module.exports = function( _, postal ) {
			return factory( _, postal );
		}
	} else if ( typeof define === "function" && define.amd ) {
		// AMD. Register as an anonymous module.
		define( ["underscore", "postal"], function ( _, postal ) {
			return factory( _, postal, root );
		} );
	} else {
		// Browser globals
		factory( root._, root.postal, root );
	}
}( typeof global !== "undefined" ? global : this.window || this.global, function ( _, postal, global, undefined ) {
    // module code here....
});

Yah, I almost slapped my own forehead when I realized this.window finds window when this == window or document == window. Kinda neat.

It's still unclear to me why you need to export a factory for node in order to support singletons. Maybe I just haven't played with node enough to know why singletons can be a problem. Is this why? Interesting. So how is that factory called? How do you get the "true singletons" into that factory? (Sorry if I'm being too curious for you. :) )