FireFox

Kerberos authentication on a Mac OS X workstation with Chrome

Kerberos authentication allows your computer to log into certain services automatically without you having to enter (and re-enter) your password (it's a SSO—single sign-on—service). Kerberos v5 is baked into Windows and Internet Explorer and works great with many LDAP-enabled services (for example, Drupal's LDAP module allows includes a submodule for SSO support).

Kerberos is built into Mac OS X as well, but isn't as simple to use and configure with Chrome and FireFox as it is with Explorer on a Windows workstation. You need to do two things before you can use Kerberos for authentication in Chrome/FireFox: