Mozilla announced last year that Firefox OS initiative of shipping phones with commercial partners did not bring the returns it sought. The company earlier this year hinted that it intends to shut the project. It is now sharing how it will deal with Firefox OS code base going forward. From their post: We would stop our efforts to build and ship smartphones through carrier partners and pivot our efforts with Firefox OS to explore opportunities for new use cases in the world of connected devices. Firefox OS was transitioned to a Tier 3 platform from the perspective of support by Mozilla's Platform Engineering organization. That meant as of January 31, 2016 no Mozilla Platform Engineering resources would be engaged to provide ongoing support and all such work would be done by other contributors. For some period of time that work would be done by Mozillaâ(TM)s Connected Devices team. We had ideas for other opportunities for Firefox OS, perhaps as a platform for explorations in the world of connected devices, and perhaps for continued evolution of Firefox OS TV. To allow for those possibilities, and to provide a stable release for commercial TV partners, development would continue on a Firefox OS 2.6 release. In parallel with continued explorations by the Connected Devices team, we recognized there was interest within the Mozilla community in carrying forward work on Firefox OS as a smartphone platform, and perhaps even for other purposes. A Firefox OS Transition Project was launched to perform a major clean-up of the B2G code bringing it to a stable end state so it could be passed into the hands of the community as an open source project. In the spring and summer of 2016 the Connected Devices team dug deeper into opportunities for Firefox OS. They concluded that Firefox OS TV was a project to be run by our commercial partner and not a project to be led by Mozilla. Further, Firefox OS was determined to not be sufficiently useful for ongoing Connected Devices work to justify the effort to maintain it. This meant that development of the Firefox OS stack was no longer a part of Connected Devices, or Mozilla at all. Firefox OS 2.6 would be the last release from Mozilla. Today we are announcing the next phase in that evolution. While work at Mozilla on Firefox OS has ceased, we very much need to continue to evolve the underlying code that comprises Gecko, our web platform engine, as part of the ongoing development of Firefox. In order to evolve quickly and enable substantial new architectural changes in Gecko, Mozilla's Platform Engineering organization needs to remove all B2G-related code from mozilla-central. This certainly has consequences for B2G OS. For the community to continue working on B2G OS they will have to maintain a code base that includes a full version of Gecko, so will need to fork Gecko and proceed with development on their own, separate branch.