We need system.js to be instantiable and let bootstrap to instantiate it. Also jsdoc + unit test wanted.

This one seems pretty simple, I'll take it.

Signing up as the backup assignee of this bug :)

Sure thing Tim :) I have a million things to do - so if you're interested it's all yours. Otherwise feel free to send it back to me.

This bug is not as easy to solve as it seems. First of all, I don't know if I should <script defer> system.js and/or bootstrap.js. If we defer them, nothing (e.g. event listeners) will be run before the DOM is ready, therefore we might lose some time to show something fast like the init logo. I have also investigated more and it seems bug 793082 is still valid in terms making sure mozChromeEvent timing issue. However, bug 924032 moved launch request away from mozChromeEvent, so I would worry we would miss that. Given the fact it will probably not a bug fixable here, I will ignore that.

The other problem around NOT using <script defer> for bootstrip.js is that DOMContentLoaded is currently affected by bug 688580, so there is no way for non-defered script to get a consistent callback at the moment right after all other deferred scripts.

I was looking at this a bit earlier, and we probably do need a *single* non-deferred object. My thoughts were that we could combine system.js and bootstrap.js into a single app containing class. Things that don't need to be there onload could be moved into other files, or within a bootstrap method. E.g., in a new app.js: function App() { ... // Add any necessary listeners window.addEventListener('load', this.bootstrap.bind(this)); window.addEventListener('mozChromeEvent', this); } App.prototype = { bootstrap: function() { this.activities = new Activities(); this.devtoolsView = new DevtoolsView(); this.ttlView = new TTLView(); // Other new and exciting classes. } }; // Inside same file (or app_init.js for easy unit testing) window.app = new App(); Anyway, I'm not sure if it solves your problem - but just throwing my thoughts in here.

Anything needs to be done here is probably all covered in bug 1094759.