By closing support to Firefox 52.9 ESR this September, Mozilla finally abandoned all XUL overlay, bootstrap and jetpack extensions. Firefox ESR 52 is the final release that is compatible with legacy add-ons. Simultaneously Mozilla will start to disable legacy add-ons on addons.mozilla.org. All classical (legacy) add-on versions will be disabled in October, 2018 and won't be available anymore. Once this happens, users will no longer be able to download their extensions. That's because Mozilla folks are disabling add-ons' versions.
https://blog.mozilla.org/addons/2018/08/21/timeline-for-disabling-legacy-firefox-add-ons/
To restore Firefox 52.9 ESR after its automatic update to Firefox 60.x
1. Download
Windows
https://ftp.mozilla.org/pub/firefox/releases/52.9.0esr/win64/en-US/Firefox%20Setup%2052.9.0esr.exe
https://ftp.mozilla.org/pub/firefox/releases/52.9.0esr/win32/en-US/Firefox%20Setup%2052.9.0esr.exe
Linux:
https://ftp.mozilla.org/pub/firefox/releases/52.9.0esr/linux-x86_64/en-US/firefox-52.9.0esr.tar.bz2
https://ftp.mozilla.org/pub/firefox/releases/52.9.0esr/linux-i686/en-US/firefox-52.9.0esr.tar.bz2
https://www.mozilla.org/en-US/firefox/organizations/
2. Installation and Profiles
Set the update preferences to "Never check for updates to prevent autoupdate to Firefox 60 and later.
This method works in Linux Mint Cinnamon and with slight variations in many Ubuntu and Debian based systems:
a.)
Extracting tarball
If directory /opt doesn't exist:
sudo mkdir /opt
Open terminal in the Download directory and extract archive to /opt:
sudo tar -xvjf firefox-52.9.0esr.tar.bz2 -C /opt
(Replace firefox-52.9.0esr.tar.bz2 file name for your version)
b.)
Linking the new Firefox ESR
sudo ln -s /opt/firefox/firefox /usr/bin/firefox-esr52
c.)
Creating a shortcut
Right-click on the Desktop and choose Create a new launcher here...
(or edit your system menu directly )
In the Launcher Properties window browse from the Command field to /usr/bin/firefox-esr52
In the Name field enter Firefox-ESR52
Click on the generic icon on the left and browse to /opt/firefox/browser/icons/mozicon128.png and select it, then click OK.
Press OK to Would you like to add this launcher to the menu also?
This will create a copy of Firefox ESR alongside your current Firefox browser. You may add the Firefox ESR launcher to the Panel.
d.)
Profile
To use Firefox ESR 52.x and Firefox Quantum intermittently you need to create separate profiles directories and edit your profiles.ini accordingly:
/home/user/.mozilla/firefox/profiles.ini
To start both versions simulateously use --no-remote switch:
ESR52
--no-remote -p ESR52
Quantum
--no-remote -p Quantum
(You need to edit Firefox Quantum menu launcher)
Sample of ini file:
[General]
StartWithLastProfile=0
[Profile0]
Name=ESR52
IsRelative=1
Path=ESR52
Default=0
[Profile1]
Name=Quantum
IsRelative=1
Path=Quantum
Default=0
3. Save compatible extensions (ADD-ONs) locally for future use to install your add-ons later from file.
All legacy add-on versions will be disabled on addons.mozilla.org in October 2018.
Example:
Search for noscript at https://addons.mozilla.org/en-US/firefox/
https://addons.mozilla.org/en-US/firefox/addon/noscript/
Scroll down to Version History
Click See all versions
Go back to the compatible version (look for the green button)
Click to install or save link as the *.xpi file
Some popular or useful extensions:
https://addons.mozilla.org/en-US/firefox/addon/adblock-plus/
https://addons.mozilla.org/en-US/firefox/addon/blank-your-monitor-easy-readin/
https://addons.mozilla.org/en-US/firefox/addon/classicthemerestorer/
https://addons.mozilla.org/en-US/firefox/addon/colt/
https://addons.mozilla.org/en-US/firefox/addon/decentraleyes/
https://addons.mozilla.org/en-US/firefox/addon/ghostery/
https://addons.mozilla.org/en-US/firefox/addon/lastpass-password-manager/
https://addons.mozilla.org/en-US/firefox/addon/noscript/
https://addons.mozilla.org/en-US/firefox/addon/privacy-badger17/
https://addons.mozilla.org/en-US/firefox/addon/quickproxy/
https://addons.mozilla.org/en-US/firefox/addon/refcontrol/
https://addons.mozilla.org/en-US/firefox/addon/ublock-origin/
https://addons.mozilla.org/en-US/firefox/addon/a-cookie-manager/
https://addons.mozilla.org/en-US/firefox/addon/add-to-search-bar/
https://addons.mozilla.org/en-US/firefox/addon/clear-flash-cookies/
https://addons.mozilla.org/en-US/firefox/addon/context-search/
https://addons.mozilla.org/en-US/firefox/addon/cookie-autodelete/
https://addons.mozilla.org/en-US/firefox/addon/cookie-quick-manager/
https://addons.mozilla.org/en-US/firefox/addon/cookies-manager-plus/
https://addons.mozilla.org/en-US/firefox/addon/edit-cookie/
https://addons.mozilla.org/en-US/firefox/addon/find-replace-for-text-editing/
https://addons.mozilla.org/en-US/firefox/addon/its-all-text/
https://addons.mozilla.org/en-US/firefox/addon/pinger/
https://addons.mozilla.org/en-US/firefox/addon/save-text-to-file/
https://addons.mozilla.org/en-US/firefox/addon/session-manager/
https://addons.mozilla.org/en-US/firefox/addon/tab-mix-plus/
https://addons.mozilla.org/en-US/firefox/addon/tab-session-manager/
https://addons.mozilla.org/en-US/firefox/addon/transliterator/
Autofill Forms
Certificate Patrol
ChatZilla
Clear Fields
deduplicate-tabs
Disable Ctrl-Q and Cmd-Q – Add-ons for Firefox
DownThemAll!
Form History Control
https://formhistory.blogspot.com/
FoxyProxy Basic
FoxyProxy Standard
Greasemonkey
HTTP Header Live
Image Zoom
infoRSS
Pale Moon: infoRSS Reloaded
Keybinder
Keybinder (github)
Live HTTP Headers
Lock The Text
New Tab in Tab Context Menu
Private Tab
Session Resurrection
SQLite Manager
Stylus
Tabboo - Session Manager
Tab Mix Plus
Torrent Status Tool
4. Alternative browsers that supports legacy Add-Ons
So, you can either use Firefox 52 ESR or/and several other browsers that support the XUL add-on interface:
Pale Moon
https://www.palemoon.org/
Basilisk
https://www.basilisk-browser.org/
WaterFox
https://www.waterfoxproject.org/
SeaMonkey
https://www.palemoon.org/
