What javascript module api does duojs use?

I'm using duojs, which is a front-end webdevelopment tool not unlike browserify or component. It allows you to import css and js straight from the file itself, without any external package manifests.

I'm trying to understand how to write my js so it works well with duojs, but am not sure what kind of architecture it uses for its module definitions. I've looked for it in the documentation, but couldn't find it there. From what I can tell it looks like the duojs compiler wraps all components in commonjs style wrappers:

See for example this compiled js file on their repo (below is a snippet):

 /**
* Return newest require.
*/
return require;
})({
1: [function(require, module, exports) {
/**
* Module Dependencies
*/
var Highlight = require('segmentio/highlight');
/**
* Code highlighting.
*/
new Highlight()
.use(require('segmentio/highlight-javascript'))
.use(require('segmentio/highlight-xml'))
.use(require('segmentio/highlight-css'))
.use(require('segmentio/highlight-json'))
.all();

Can anyone tell from the code what kind of js module api is being used here? To me this looks like a commonjs style module definition, but I'm not sure, it might be node as well.