Users who wish to continue using legacy Firefox extensions can use Firefox ESR 52. It will receive security updates through April 2018 at which point it will mo

Users who wish to continue using legacy Firefox extensions can use Firefox ESR 52. It will receive security updates through April 2018 at which point it will move to a later version of Firefox which no longer supports legacy extensions. Over the next 5 months, the WebExtensions API will continue to be expanded enabling more of the older extensions' features to work with the modern extensions framework.