Sony lifts skirt on Firefox OS with developer ROM for Xperia E

Ubuntu's not the only half-baked mobile OS around

The Mozilla Foundation doesn't expect the first phones running its Firefox OS to appear until this summer – and even then, only in select markets – but developers can start tinkering with the platform on real hardware today, thanks to Sony Mobile.

Just days after Mozilla announced the first commercial release of Firefox OS at the Mobile World Congress in Barcelona, Sony has released a flashable Firefox OS firmware image for its Xperia E handsets.

"Now we're ready to share our initial experiments on Firefox OS with the tech community, to get valuable feedback," company reps wrote in a statement on Wednesday. "More importantly, we want to reach out to the application community and support the early adopters who can start to develop applications for Firefox OS."

They mean it about that last part. Much like the experimental Ubuntu Touch Developer Preview images released by Canonical last week, Sony's Firefox OS build is not intended for daily use, and the company recommends you don't mess around with it unless you're an experienced developer.

For now, the only model it works on is the Xperia E, which Sony says was chosen because its hardware closely resembles Mozilla's recommended baseline specs for Firefox OS.

To flash the ROM, you'll first need to unlock the phone's bootloader. Sony provides a tool for this, but it cautions that doing so may void the phone's warranty, and that some carriers may have implemented additional protections that prevent the tool from working. In addition, unlocked phones will stop receiving official software updates from Sony.

And don't expect the world once you get Firefox OS up and running, either – or even a phone, for that matter. Not only is mobile carrier connectivity not working in this build, but neither are Wi-Fi and Bluetooth.

You know what? Rather than going through all the trouble, maybe you should just watch the video

That leaves you with a pretty limited range of things you can do with Firefox OS on the Sony hardware for now, and a limited number of applications you can build for it, too. Nothing that requires network connectivity will work.

Still, if you're eager to get a feel for how Firefox OS will function on fairly modest hardware, here's your chance – and don't worry, you can always flash your phone back to Android once you're done exploring.

If this developer build sounds too unfinished for you, on the other hand, Spanish startup Geeksphone plans to ship two more-fully-featured Firefox OS devices for developers soon, and you only have a few months to wait before finished, commercial devices become available.

At its Mobile World Congress event on Sunday, Mozilla said that "the first wave" of Firefox OS handsets will go on sale to consumers in Brazil, Colombia, Hungary, Mexico, Montenegro, Poland, Serbia, Spain, and Venezuela beginning this summer, with additional markets to be announced soon. ®