Firefox

Process manager

Firefox has a process manager now, open:

about:processes

The process manager can also be opened with the keyboard shortcut Space+Esc or from More Tools -> Task Manager in the menu.

Screenshots

You can take screenshots directly in Firefox to capture an entire web page, not just the visible parts (which is also possible in Firefox, but your desktop manager can also do that).

The keyboard shortcut is Space+Control+S, or you can right-click on an empty part of the page and select Take screenshot. You can also add a button to the toolbar from More Tools -> Customize Toolbar and drag/dropping the screenshot button into the toolbar.

Add-ons

Firefox add-ons that I find useful:

Ubuntu

Using Mozilla's PPA

Ubuntu now installs Firefox with snap, but Mozilla actively maintain a PPA repository with the latest stable Firefox release (as well as Firefox ESR and Thunderbird).

Start by removing the snap version that Ubuntu installs:

$ sudo snap remove firefox
$ sudo systemctl stop var-snap-firefox-common-host.mount
$ sudo systemctl disable var-snap-firefox-common-host.mount

Ubuntu has a packages named firefox, which is a meta package for wrapping the snap-installed Firefox, which has to be removed:

$ sudo apt-get purge firefox

Then add the PPA from Mozilla:

$ sudo add-apt-repository ppa:mozillateam/ppa

Ubuntu will still prefer its package that installs Firefox with snap, so create /etc/apt/preferences.d/mozilla-firefox to prioritize the PPA over the Ubuntu repos for the firefox package:

Package: firefox*
Pin: release o=LP-PPA-mozillateam
Pin-Priority: 501

Package: firefox*
Pin: release o=Ubuntu
Pin-Priority: -1

After updating the cache, apt should prefer the Mozilla PPA package:

$ sudo apt update
$ apt-cache policy firefox
firefox:
  Installed: (none)
  Candidate: 116.0.3+build2-0ubuntu0.23.04.1~mt1
  Version table:
     1:1snap1-0ubuntu3 -1
        500 http://de.archive.ubuntu.com/ubuntu lunar/main amd64 Packages
     116.0.3+build2-0ubuntu0.23.04.1~mt1 501
        500 https://ppa.launchpadcontent.net/mozillateam/ppa/ubuntu lunar/main amd64 Packages

Then install the firefox package:

$ sudo apt install firefox

References