So you want to install the latest version of FireFox in CentOS 7, eh?
I followed the directions that are laid out, at the following web site, with some slight modifications for my Gnome Desktop.
First, Download the latest Version, in my case 45.o.1, from Mozilla:
Go to the web site. (you will have to modify the URL to suit the version)
and download the file: firefox-45.0.1.tar.bz2
<TERMINAL> su <MY ROOT PASSWORD> cd /home/myusername/Downloads tar xjf firefox-45.0.1.tar.bz2 mv firefox /opt/firefox ln -s /opt/firefox/firefox /usr/bin/firefox-latest cd /usr/share/applications cp firefox.desktop firefox-latest.desktop nano firefox-latest.desktop [Desktop Entry] Version=1.0 Name=FireFox Latest ... Exec=/usr/bin/firefox-latest %u ... <CTRL-X> y <ENTER> <LOG OUT> <LOG IN>
And you should now have a shortcut that will launch the latest version of FireFox.
And, apparently, it will update itself. This has yet to be tested.