supporting both CommonJS and AMD

Yes, and I owe this answer to ded and his awesome modules:

(function(name, definition) {
    if (typeof module != 'undefined') module.exports = definition();
    else if (typeof define == 'function' && typeof define.amd == 'object') define(definition);
    else this[name] = definition();
}('mod', function() {
    //This is the code you would normally have inside define() or add to module.exports
    return {
        sayHi: function(name) {
            console.log('Hi ' + name + '!');
        }
    };
}));

This can then be used:

1. in AMD (e.g. with requireJS):

   requirejs(['mod'], function(mod) {
       mod.sayHi('Marc');
   });
   

2. in commonJS (e.g. nodeJS):

   var mod = require('./mod');
   mod.sayHi('Marc');
   

3. globally (e.g. in HTML):

   <script src="mod.js"></script>
   <script>mod.sayHi('Marc');</script>
   

This method needs to get more publicity - if jQuery and co. started using it life would be much easier!

Here is a list of various cross-compatible module formats.

I suspect that the one you're looking for is what they're calling "commonjsStrict.js"

uRequire, the Universal Module & Resource Converter is the tool that does exactly that.

• It mainly converts AMD and CommonJS to UMD / AMD / CommonJS / Plain script (no AMD loader required).

• It allows declarative exporting of modules, with a noConflict() baked in.

• It can manipulate modules (inject/replace/remove dependencies OR code) as you build them.

• It converts from coffeescript, coco, Livescript, icedCoffeescript and you can add your own conversions in one liners!