> 2. Android in particular is really nasty at the low end. The quality of experience you would get from a tightly optimised and simplified Firefox OS would be immeasurably better.
Firefox OS is worse here, not better. Gingerbread runs far better on low end hardware than Firefox OS does. The later Android stuff is more demanding (particularly in RAM), but the performance target (60fps everywhere, low latency) is also much, much higher than what Firefox OS is capable of achieving.
Firefox OS is less efficient than iOS, Android, or WP. By a lot.
Go look at any hands on video or flash it yourself on a device that runs Android. It's clear as day that Firefox OS is far from fast and responsive on hardware that Android doesn't have issues with. And this makes a ton of logical sense, as it would be a goddamn miracle if Mozilla managed to make web technologies an order of magnitude faster and more memory efficient than anyone else.
Or hell, just run Firefox on your existing Android device - that's all Firefox OS is in reality. Mozilla makes a bunch of claims about how it's "closer to the metal" or some such nonsense, but it isn't. It's not like Android runs all native code in a VM - it's as "close to the metal" as you can get, with the exception that system calls go to the kernel. Just as they do in Firefox OS. Particularly since Firefox OS is built on top of Android.
> It's not like Android runs all native code in a VM - it's as "close to the metal" as you can get
Can you please explain how Dalvik[1] isn't a VM? Sorry if I am missing your point.
Are you referring to the NDK[2]? I haven't used it but my understanding was that Dalvik is still used for UI and basic process control, while calling out to native code via JNI.
I was referring to the NDK. The NDK is perfectly capable of input & drawing - it's what many games use, for example. It's also what Firefox uses. Well, Firefox is a hybrid - a mix of Java and native. But the web parts are all native running outside of dalvik and drawing directly to a surface via OpenGL.
The lower-level "operating system" of b2g. Gonk consists of a linux kernel and userspace hardware abstraction layer (HAL). The kernel and several userspace libraries are common open-source projects: linux, libusb, bluez, etc. Some other parts of the HAL are shared with the android project: GPS, camera, among others. You could say that Gonk is an extremely simple linux distribution.
Firefox OS is worse here, not better. Gingerbread runs far better on low end hardware than Firefox OS does. The later Android stuff is more demanding (particularly in RAM), but the performance target (60fps everywhere, low latency) is also much, much higher than what Firefox OS is capable of achieving.
Firefox OS is less efficient than iOS, Android, or WP. By a lot.