This article will explain how to install Firefox developer edition in Manjaro OS along side Firefox stable version which you may have already installed.
The installation is very straight forward because Firefox developer edition is available from official community repository.
Install Firefox developer via pamac
In Manjaro systems by default have Pamac package manager to install/remove applications and libraries. Just open Pamac, search for Firefox developer and click on the install button.
Install Firefox developer via pacman
You can also install applications from terminal, fire the following command to install Firefox developer in Manjaro.
pacman -S firefox-developer-edition
To remove it:
pacman -R firefox-developer-edition
Upgrading
In most cases you will be notified by the package manager to upgrade when updates are available. You can do system upgrade via pacman in terminal by running pacman -Syu
Or open pamac gui and select individual package for upgrading.