For the sake of simplicity, we are going to assume that you are me and your home directory is "/home/john/". So replace my home directory with yours anytime you see it in a command. You can find your home directory by opening a terminal and typing:

cd

followed by:

pwd

1. First you are going to need the the latest Firefox 2 release candidate. You can get it here. Remember where you downloaded it to. (I like to place all my files in a directory named dls in my home directory, so they are easy to find.)

2. Now open a terminal window. (Main Menu -> Accessories -> Terminal)

3. Create a backup of your current Firefox profile (just in case - backups are always a good thing).

cp -r /home/john/.mozilla /home/john/.mozilla-bkup

4. Create a directory called testing in your home directory. This is where we are going to install Firefox. I like to do this with software that I am testing as it makes deleting it much easier and doesn't require any superuser privileges.

mkdir /home/john/testing

5. Create a directory for the "new" Firefox install to use for your profile inside the testing directory you just created.

mkdir /home/john/testing/profile

6. Change directories to the "testing" directory you created in step 3.

cd /home/john/testing

7. Now extract Firefox in to the testing directory.

tar xzf /home/john/dls/firefox-2.0rc1.tar.gz

8. Change directories back to your home directory.

cd

9. Copy some the Flash and Java plugins from your current Firefox install. You can skip this if you don't care about Flash and Java. (Each cp command should be only one line, just in case the formating throws it off)

cp /usr/lib/jvm/java-1.5.0-sun/jre/plugin/i386/ns7-gcc29/libjavaplugin_oji.so /home/john/testing/firefox/plugins/

cp /usr/lib/flashplugin-nonfree/* /home/john/testing/firefox/plugins/

(This assumes that you installed Flash and Java from the official Ubuntu repositories, if not you will have to find these files yourself and copy them to Firefox's plugin directory, just like we did above. No worries if you can't find them, this is not a required step.)

10. Launch your new install of the latest Firefox 2 release candidate. (Make sure any open Firefox windows are closed first.)

/home/john/testing/firefox/firefox -profile /home/john/testing/profile/

Note the -profile option, this tells Firefox not use the default location for your profile and instead use the directory we created. This is key to running two separate version of Firefox. Without it your stable profile may become corrupted.

At this point you should have a completely working install of the latest Firefox 2 release candidate that is completely separate from your original "stable" Firefox install. One thing that you should know is you cannot have both versions of Firefox running at once. If you try to open a different version, the currently running version will just create a new window. If you would like to launch Firefox 2 without the terminal, simply create a new custom launcher on either your desktop or panel using the command from step 10 as the "command" for the launcher.

If for some reason you do mess up your "stable" Firefox profile (which you shouldn't following this how to), just open a terminal and issue

cp -r /home/john/.mozilla-bkup /home/john/.mozilla

to restore your profile from the backup we made in step 3.

To uninstall Firefox 2 just delete your testing folder or just the Firefox folder if you want to keep your profile. (Just be careful typing this command, it is possible to delete your whole home directory if you hit enter too soon.)

rm -rf /home/john/testing

or

rm -rf /home/john/testing/Firefox

depending on what you want to uninstall (the whole shebang or just the Firefox directory)

Firefox 2 Release Candidate 1 Release Notes
Firefox 2 Release Candidate 1 Download
computers, software, browsers, Linux, Ubuntu, Firefox, release candidate