B2G is a community maintained open source operating system for smartphones, tablets, smart TVs and other connected devices. The project was started in 2011 and is based on the Linux kernel and Gecko rendering engine. The entire user interface is built using web technologies (HTML, CSS and JavaScript) and can be used to launch and use web applications. Since Mozilla discontinued their commercial Firefox OS smartphone programme the smartphone part of the project is entirely maintained by Mozilla's volunteer community.

Note: Currently, B2G OS is in a transition phase. You can help us to get things done faster — see the "how you can help" section below. Also a Call for contributors has been made to gather more people, feel free to share it !
How you can help
- Test the transition branch
- File bugs (meta bug is bug 1252143)
- Fix bugs
- Help us fix failing tests
- Port a gaia smartphone app,
- Turn it into a web app (or)
- Turn it into chrome (why?) & report back your findings
- Help us maintain a device port
- Help improve & translate this documentation
- (Eventually) propose/implement new smartphone features.
Get involved
- Mailing list (dev-fxos)
- IRC (irc.mozilla.org #fxos)
- Discourse
- Telegram group: B2GOS
- Wiki
- B2G Weekly Meeting for engineering status updates.
- Participate to Transition meetings and Community Working Groups meetings, register on this Calendar.
They are announced on Discourse, were you can find information about how to attend and the notes.
Supported devices
Information on supported phones running B2G OS:
- Sony Xperia Z3C (developer phone)
- Flame (developer phone)
- ZTE Open C (WIP)
- Fairphone 2 (WIP)
- Sony Xperia Z1C (WIP)
- Sony Xperia E3 (WIP)
For more information see this page.
Get started with B2G OS add-ons
To start developing add-ons and getting involved in the add-ons community, read Getting started with B2G OS add-ons.
Note: some pages have been moved to the MDN Archive — let us know if you have trouble finding anything, or if there is anything in the archive that you feel should be moved back to this section.