Anne van Kesteren

Firefox OS is not helping the web

Mozilla has been working on Firefox OS for quite a while now and ever since I joined I have not been comfortable with it. Not the high-level goal of turning the web into an OS, that seems great, but the misguided approach we are taking to get there.

The problem with Firefox OS is that it started from an ecosystem parallel to the web. Packaged applications written using HTML, JavaScript, and CSS. Distributed through an app store, rather than a URL. And because Mozilla can vet what goes through the store, these applications have access to APIs we could never ship on the web due to the same-origin policy.

This approach was chosen in part because the web does offline poorly, and in part because certain native APIs could not be made to work for the web and alternatives were not duly considered. The latest thinking on Firefox OS does include URLs for applications, but the approach still necessitates a parallel security model to that of the web. Implemented through a second certificate authority system, for code. With as sole authority Mozilla, and a “plan” to decentralize that over time.

As stated, the reason is APIs that violate the same-origin policy, or more generally, go against the assumed browser sandbox. E.g., if Mozilla decides your code is trustworthy, you get access to TCP and can poke around the user’s local network. This is quite similar to app stores, where typically a single authority decides what is trustworthy and what is not. With app stores the user has to install, but has the expectation that the authority (e.g., Apple) only distributes trustworthy software.

I think it is wishful thinking that we could get the wider web community to adopt a parallel certificate authority system for code. The implications for the assumed browser sandbox are huge. Cross-site scripting vulnerabilities in sites with extra authority suddenly result in the user’s local network being compromised. If an authority made a mistake during code review, the user will be at far more risk than usual.

The certificate authority system the web uses today basically verifies that when you connect to, it actually is, and all the bits come from there. And that is already massively complicated and highly political. Scaling that system, or introducing a parallel one as Firefox OS proposes, to work for arbitrary code seems incredibly farfetched.

What we should do instead is double down on the browser. Leverage the assumed browser sandbox. Use all the engineering power this frees up to introduce new APIs that do not require the introduction and adoption of a parallel ecosystem. If we want web email clients to be able to connect to arbitrary email servers, let’s back JMAP. If we want to connect to nearby devices, Fly Web. If we want to do telephony, let’s solidify and enhance the WebRTC, Push, and Service Worker APIs to make that happen.

There are many great things we could do if we put everyone behind the browser. And we would have the support of the wider web community. In the sense that our competitors would feel compelled to also implement these APIs, thereby furthering the growth of the web. As we have learned time and again, the way to change the web is through evolution, not revolution. Small incremental steps that make the web better.