Temporarily install old version of Firefox for testing

install-old-firefox.sh

# Firefox 33 was the last version to support SSLv3 (https://blog.mozilla.org/security/2014/10/14/the-poodle-attack-and-the-end-of-ssl-3-0/)
#firefox_version=33.0
# Firefox 51 was the last version to support NPAPI plugins (e.g. Java) (https://support.mozilla.org/en-US/kb/npapi-plugins)
#firefox_version=51.0
# Firefox 56 was the last version to support XPCOM- and XUL-based add-ons (https://blog.mozilla.org/addons/2016/11/23/add-ons-in-2017/)
#firefox_version=56.0

wget https://ftp.mozilla.org/pub/firefox/releases/$firefox_version/linux-x86_64/en-US/firefox-$firefox_version.tar.bz2
tar -xvf firefox-$firefox_version.tar.bz2
mv firefox firefox-$firefox_version
cd firefox-$firefox_version
mkdir profile
# Disable automatic updates and default browser check
echo "user_pref(\"app.update.auto\", false);
// Same thing, for older versions of Firefox
user_pref(\"app.update.enabled\", false);
user_pref(\"browser.shell.checkDefaultBrowser\", false);
// Fix tabs crashing on older versions (https://support.mozilla.org/kn/questions/1167673)
user_pref(\"browser.tabs.remote.autostart\", false);" > profile/user.js
./firefox --profile profile