Manual main switching

gistfile1.js

// For any third party dependencies, like jQuery, place them in the lib folder.

// Configure loading modules from the lib directory,
// except for 'app' ones, which are in a sibling
// directory.
requirejs.config({
    baseUrl: 'lib',
    paths: {
        app: '../app'
    }
});

var main = 'app/main',
    scriptNode = document.querySelector('[data-postmain]');
if (scriptNode) {
  main = scriptNode.dataSet.postmain;
}
requirejs([main]);