https://wccftech.com/firefox-78-out-today-with-a-refresh-button/

Mozilla has launched Firefox 78 for Windows, macOS, and Linux, bringing accessibility features, new Refresh button, and video call improvements. This version is the last of the browser supporting OS X 10.9 Mavericks, OS X 10.10 Yosemite, and OS X 10.11 El Capitan.

"These users will be moved to the Firefox Extended Support Release (ESR) channel by an application update," the browser maker said. "This will provide security updates until the next ESR update in July 2021, after which the affected users will no longer receive security updates."