Extensions explicitly designed for the old extension system still work. https://github.com/gorhill/uBlock-for-firefox-legacy https://github.com/gorhill/uBlock-

Extensions explicitly designed for the old extension system still work. https://github.com/gorhill/uBlock-for-firefox-legacy https://github.com/gorhill/uBlock-for-firefox-legacy Also works with Pale Moon. There are even special builds of Pale Moon that will run on Windows XP.