Firefox OS: Tracking reflows and event loop lags

We could have used (and contributed momentum to!) already existing, open source Linux-based components wrapped up in an existing mobile OS which has already been deployed and shown working on several nice devices and is extremely capable, allowing you to do essentially whatever you can do on a computer (Maemo/Meego/Tizen/Sailfish family). In basically whatever language you want. Because, it IS a computer using a real computer OS which, for those who want it, allows all the control that a Linux computer allows to the user, not just a crummy sandbox.

And also there would not be such fundamental performance issues to iron out for several years before the platform became remotely suitable for human consumption.

And we wouldn't be pointlessly fighting a two-front battle, not only against iOS and Android etc., but also against every other concurrent attempt to bring a real, uncrippled open source, stack to mobile phones.

But... nah... we have plenty of time... let's build an entire NEW, NIH-based operating system!

And make sure that every function absolutely must be performed inside a web browser, and depends on Javascript, but with lots of ad hoc new APIs that are not otherwise applicable. Then we can work furiously to make it perform. And everyone who wants to touch our platform is required to deal with the incredible annoying pain of current Javascript web app development every time they want to write anything at all, forever.

Welcome to the future, now you must rewrite every capability in Javascript (one of the worst languages everyone has to use) even when there are already high-quality implementations in other languages. We don't want those here.

Because we don't just think Javascript is handy due to browsers already supporting it, as a matter of historical accident. We could have used literally anything. We actually sat down and decided there wasn't one single better language than Javascript to write a mobile OS in, and to require everyone to use to access our platform. Not even languages which have been used forever to make OSes, and mobile OSes. Not even a system which would allow choice of languages. Only Javascript. Only our new app API that we just came up with.

But give us a few years to implement acceptable FPS as a "feature" on our phone operating system targeted at weak hardware.

  Firefox OS will also support scrolling in a different 
  thread (async pan and zoom), which will make scrolling 
  possible even if the event loop is blocked.

That's a great news!

I found the video of how browser's compute the layout of page and reflow elements accordingly really cool. Is there a setting I can flip to view this in action on websites I am working on? I think it would be useful in debugging page rendering performance.

He says this is for FFOS 1.4+. When will this make its way to the public? Mozilla Hacks has some directions on how to get 1.2 on your ZTE Open [1], but I've seen nothing about 1.3 let alone 1.4.

[1] https://hacks.mozilla.org/2014/01/upgrading-your-zte-open-to...

That makes me wonder, how much code do Firefox OS and Firefox Browser have in common? Was just thinking if some of the advances of the mobile OS world could benefit the browser as well :).

I haven't followed Firefox OS so this was a surprise to me. I noticed their use of adb and logcat. From a platform perspective, how much is in common between Firefox OS and android?