Firefox 3 in F8 & F7

NOTE: As of this writing, Firefox 2 is still the latest officially supported browser version available in F8 & F7. Until or unless Firefox 3 is available in Fedora's own updates repo, using remi's packages is still the easiest and safest way to install it. Also note that remi's repo now contains the FINAL version (was beta previous to 2008-06-18)

1. Install Remi's repo:
   

# for Fedora 8
su -c 'rpm -ivh http://rpms.famillecollet.com/remi-release-8.rpm'

# for Fedora 7
su -c 'rpm -ivh http://rpms.famillecollet.com/remi-release-7.rpm'

2. Install FireFox3:

su -c 'yum --enablerepo remi install firefox3'

3. Run Firefox3 the first time using its ProfileManager to create a NEW profile just for firefox3, or it will screw up your existing Firefox2 profile (incompatible plugins, themes, etc.). Run the following, click Create Profile, name it "firefox3", then click EXIT instead of starting it:
   

firefox3 -ProfileManager -no-remote

4. Now that the profile is created, run the following to choose it automatically (or create a new launcher to run it). This allows you to run both Firefox3 and Firefox2 at the same time without conflicts (though new windows will still open in firefox2 by default).
   

firefox3 -P firefox3 -no-remote

5. Check for beta updates in the remi repo once in a while (rather than enabling remi by default):
   

yum --en remi update firefox3

6. OPTIONAL STEP: Edit /etc/yum.repos.d/remi.repo to have it enabled by default, and to only allow updates to a restricted list of packages (changes in BOLD below). Without restricting remi's packages to a whitelist using "includepkgs", a "yum update" with remi enabled will result in unwanted packages (mostly php*) attempting to overwrite your supported fedora packages; this would be bad. We're only interested in remi for firefox3, thunderbird, thunderbird-enigmail, and friends.

[remi]
name=Les RPM de remi pour Fedora $releasever - $basearch
baseurl=http://rpms.famillecollet.com/fc$releasever.$basearch/
        http://remi.collet.free.fr/rpms/fc$releasever.$basearch/
        http://iut-info.univ-reims.fr/remirpms/fc$releasever.$basearch/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-remi
failovermethod=priority
includepkgs=firefox*,xulrunner*,thunderbird*

[remi-test]
name=Les RPM de remi en test pour Fedora $releasever - $basearch
baseurl=http://rpms.famillecollet.com/test-fc$releasever.$basearch/
        http://remi.collet.free.fr/rpms/test-fc$releasever.$basearch/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-remi
failovermethod=priority