Shishi is a (still incomplete) implementation of Kerberos 5, which can be used to authenticate users in distributed systems. It contains a library that can be used by application developers, and a command line utility for users. Shishi supports Kerberos authenticated telnet client/server, IMAP client/server (via GSSAPI), SSH client/server (via GSSAPI), rsh/rlogin client, and a PAM module for host security.
The HOTP Toolkit package contains tools that are useful when deploying the one-time password HOTP technology. It contains a shared library, a command-line tool to generate and validate one-time passwords, and a PAM module (pam_hotp) to make system login or SSH use HOTP one-time passwords for authentication.