Jailkit is a set of utilities to limit user accounts to specific files
using chroot() and/or specific commands.  Setting up a chroot shell, a
shell limited to some specific command, or a daemon inside a chroot jail
is a lot easier and can be automated using these utilities.

Jailkit is a specialized tool that is developed with a focus on security.
It will abort in a secure way if the configuration, the system setup or
the environment is not 100% secure, and it will send useful log messages
that explain what is wrong to syslog.

Jailkit is known to be used in network security appliances from several
leading IT security firms, internet servers from several large enterprise
organizations, internet servers from internet service providers, as well
as many smaller companies and private users that need to secure cvs,
sftp, shell, or daemon processes.