Multiple Firefox Versions on Same PC

I develop various web apps, use CSS and JavaScript extensively, and need to be able to test them on both FF 3 as well as FF 3.5.

But, installing 3.5 overwrites 3.0, so I was wondering if its possible (and if so, how) to run both Firefox 3.0 and 3.5 on the same system, or am i stuck having to use 2 different systems?

I am using Windows XP.

Thanks

Yes. Download and install them in seperate directories. Then, launch each one individually with the -p flag to set up different profiles for each version (or at least one for testing). Then, after you have two seperate profiles, create an icon for each on your desktop. Right click on the icon and select properties.

In the 'target' field, add the following flags.

c:\Programs\Firefox 3.0\firefox.exe -p Profile1 -no-remote
c:\Programs\Firefox 3.5\firefox.exe -p Profile2

This is assuming you will be using Firefox 3.5 as your main browser and 3.0 for testing. If you want it the other way around switch the -no-remote tag. This allows you to run multiple versions of Firefox side by side. For more information refer to the Mozillazine page on command line arguments.

You could also try Utilu which automates this process, and also installs the Web developer toolbar and Firebug on each version. Very handy for a test machine.

You can use the portable versions of firefox (3.5, older versions). You can install as many versions of firefox side-by-side as you want, but you can only run one version at any time.

Since Firefox 57, legacy support is withdrawn and so many useful plugins and addons are let out in the newer versions (57 onwards). I have faced the problem of keeping multiple firefox say, Firefox 56 (legacy supported) and the default, current version, which will be updated regularly by Ubuntu (say) by default.

To do that, I follow the these steps:

1. Download Firefox 56: https://ftp.mozilla.org/pub/firefox/releases/56.0/. firefox-56.0.tar.bz2 will be downloaded.

2. Extract the tar.bz2 source file in /opt/firefox56/ using:

    tar xvjf firefox-56.0.tar.bz2
   

3. Run the default firefox using the following command.

    firefox -ProfileManager 
   

   Create a new profile, say firefox56, save its data in a folder other than the default.

4. Create a soft link for firefox56

    sudo ln -s /opt/firefox56/firefox-bin /usr/bin/firefox56
   

5. Start firefox56 with the newly created profile

    firefox56 -P firefox56
   

6. Create .desktop file: firefox56.desktop in /usr/share/applications/firefox56.desktop

    [Desktop Entry]
    Version=56.0
    Name=Firefox 56
    Comment=Browse the World Wide Web
    GenericName=Web Browser
    Keywords=Internet;WWW;Browser;Web;Explorer
    Exec=firefox56 %u
    Terminal=false
    X-MultipleArgs=false
    Type=Application
    Icon=/opt/firefox56/browser/icons/mozicon128.png
    Categories=GNOME;GTK;Network;WebBrowser;
    MimeType=text/html;text/xml;application/xhtml+xml;application/xml;application/rss+xml;application/rdf+xml;image/gif;image/jpeg;image/png;x-scheme-handler/http;x-scheme-handler/https;x-scheme-handler/ftp;x-scheme-handler/chrome;video/webm;application/x-xpinstall;
    StartupNotify=true
    Actions=new-window;new-private-window;
   
    [Desktop Action new-window]
    Name=Open a New Window
    Exec=firefox56 -P firefox56
   
    [Desktop Action new-private-window]
    Name=Open a New Private Window
    Exec=firefox56 -P firefox56 -private-window
   

Done! Find both of your installation in the menu.

Here's a http://www.undermyhat.org/blog/2009/09/install-firefox-3-5-side-by-side-with-firefox-3-0-on-windows/">simple three step process to achieve the same. For people that need a little bit more help getting this up and running with multiple Firefox versions, just check it out. It'll have nice pictures to guide you through the process.

I have answered this here.

Use multiple versions of FirefoxPortable.

https://stackoverflow.com/questions/345281/is-there-a-way-to-force-firefox-to-launch-in-a-new-process/