Kerberos
Provides Kerberos 4 &5 protocols, GSSAPI, a graphical authentication interface
Kerberos for Macintosh is an implementation of the Kerberos authentication system for Mac OS X. It is based on the MIT Kerberos implementation and provides Kerberos v5 and Kerberos v4 protocols, GSSAPI, a graphical authentication interface and accompanying API for acquiring Kerberos tickets, an in-memory ticket cache and KClient compatibility.