The official version of Mozilla Firefox 77 is now available to all supported operating systems, and then we need to focus on Firefox 78, which is already in beta beta and available to users on Windows, Linux and macOS. The biggest change in this version is that the supported operating system version is changing, and not much.
Starting with this new version, the stable version of the Firefox channel will no longer get updates on some older versions of macOS. In other words, if you’re still running one of the macOS versions listed below, Firefox 78 will be the last major update and Firefox 79 will no longer support your operating system:
macOS 10.9 (Mavericks)
macOS 10.10 (Yosemite)
macOS 10.11 (El Capitan)
While this may not be good news for some older computer users who can’t upgrade their systems, given that these are older versions of the operating system, it’s likely that only a small number of users are still running, and Mozilla’s decision is likely to affect only a limited number of devices.
So what do these users do after Firefox 78 is launched? Consider changing to a browser that still supports older operating system versions, but giving up Firefox isn’t necessarily the only way out. Mozilla will continue to support macOS 10.9, 10.10 and 10.11 versions as part of Firefox ESR, so simply switch to this version allows you to stick with the browser. Of course, considering that Firefox ESR doesn’t get any new features, only security fixes and improvements, it’s not necessarily the most convenient switch, but since your device is running an outdated operating system, it’s a workaround that doesn’t work without problems.
According to third-party data provided by NetMarketShare, only 0.73% of all Apple computers are still running macOS 10.9. In the case of macOS 10.10, the figure is 2.43%, while 4.60% of macOS 10.11 devices are still in use.