Configuring the Mozilla Web browser in Windows XP is very simple, provided that the workstation is a member in the Active Directory domain. With the address
about:config you can call up the current configuration in Firefox and enter
negotiate as the filter (see Figure E-2). In the
network.negotiate-auth.trusted-uris parameter you enter all hosts or domains for which an automatic login should take place. Multiple entries are separated by spaces or commas. If a target host or its domain is not in the list, Firefox will certainly ask for the user name and password. These are transmitted in plain text, however, which is why you should prefer automatic login in all cases.
Figure E-2. Single sign-on via SPNEGO/Kerberos ...