AMD in YUI?

gistfile1.js

//in some/thing.js
define('some/thing', ['a', 'some/b'], function (a, b) {
    return 'value';
});

//YUI loader would apply the return value from the define
//as the 'some/thing' property on the YUI instance, 
//so the above module could be used like so:

//in some code that uses YUI:
YUI().use('some/thing', function (Y) {
    var thing = Y['some/thing'];
});