I suppose it shouldn't be totally unexpected given the end of FirefoxOS phone development a few months ago, but a platform going from supported to take-it-completely-out-of-mozilla-central in less than a year is rather startling: not only has commercial development on FirefoxOS completely ceased (at version 2.6), but the plan is to remove all B2G code from the source tree entirely. It's not an absolutely clean comparison to us because some APIs are still relevant to current versions of OS X macOS, but even support for our now ancient cats was only gradually removed in stages from the codebase and even some portions of pre-10.4 code persisted until relatively recently. The new state of FirefoxOS, where platform support is actually unwelcome in the repository, is beyond the lowest state of Tier-3 where even our own antiquated port lives. Unofficially this would be something like the "tier WONTFIX" BDS referenced in mozilla.dev.planning a number of years ago.

There may be a plan to fork the repository, but they'd need someone crazy dedicated to keep chugging out builds. We're not anything on that level of nuts around here. Noooo.

http://tenfourfox.blogspot.com/2016/09/firefox-os-goes-tier-wontfix.html