We're looking at moving users on versions < 10.12 to the esr branch with the release of Firefox 78, to both be able to support them for about a year longer, and reduce the burden from old versions on engineering and QA for mainline Firefox.Ī meta bug has been created on Bugzilla that tracks the migration process. We currently support macOS versions 10.9 to 10.15. Why is that done? Mozilla notes on Bugzilla: Mozilla plans to end support for Mac OS 10.9 to 10.11 (Mac OS X Mavericks, Yosemite, and El Capitan) next year Firefox Stable installations on these systems will be migrated to Firefox ESR 78 when the new version is released on June 30, 2020. The release of Firefox 78 and Firefox ESR 78 changes that.
