Users who rely on specific legacy extensions that were rendered incompatible with Firefox Quantum (version 57+) have often stuck with the 52 ESR branch. With 52.9.0 being the end of this line, these users face a difficult decision: upgrade their OS and browser to the modern WebExtensions standard, or remain on an insecure version of the browser to keep their favorite add-ons working.
The Mozilla Foundation has officially rolled out Firefox 52.9.0 ESR (Extended Support Release). While routine updates are common in the software world, this specific release carries significant weight for users running older hardware.