Firefox can authenticate with Active Directory using Kerberos single sign-on. It works on both Macs and PCs. This allows automatic authentication to intranets or specific internal company websites.

See http://www.mozilla.org/projects/netlib/integrated-auth.html for the specifics on how it works.

Launch Firefox.  In the URL Field type about:config

Look for the following three preference names:

• network.automatic-ntlm-auth.trusted-uris
• network.negotiate-auth.delegation-uris
• network.negotiate-auth.trusted-uris.

Double click on each preference name and add ‘http://yourwebsite-1, http://yourwebsite-2, yourActiveDirectoryDomainName’ to its value field. You can add more sites as required.

Close the about:config windows and the following entries will be written into your prefs.js file which resides in the the Firefox User Profile directory:

• user_pref(”network.automatic-ntlm-auth.trusted-uris”, “http://yourwebsite-1, http://yourwebsite-2, yourADdomain”);
• user_pref(”network.negotiate-auth.delegation-uris”, “http://yourwebsite-1, http://yourwebsite-2, yourADdomain.com”);
• user_pref(”network.negotiate-auth.trusted-uris”, “http://yourwebsite-1, http://yourwebsite-2, yourADdomain.com”

You have now configured Firefox to use Integrated Authentication on your network.