k5start is a modified version of kinit that can use keytabs to authenticate,
can run as a daemon and wake up periodically to refresh a ticket, and can run
single commands with their own authentication credentials and refresh those
credentials until the command exits.

It is commonly used to maintain Kerberos tickets for services that need to
authenticate to minimize the amount of Kerberos-related logic that must be
in the service itself.

WWW: http://www.eyrie.org/~eagle/software/kstart/