Kiwi Browser is the top choice for Android users who want the full power and customization of desktop browser extensions on their mobile device.
GNU IceCat is a free and open-source web browser from the GNU Project. It is a fork of Mozilla Firefox, modified to ensure it contains 100% free software and to enhance user privacy.
Iceweasel was not a separate web browser; it was simply a renamed version of Mozilla Firefox.
CometBird was a short-lived, niche web browser that was essentially a lightly modified version of Mozilla Firefox
ReactOS
LibreWolf is a privacy-focused, open-source web browser designed to be a secure and private version of Firefox.