mod_jail is
Apache module,
that supports 1.3.xx and 2.0.xx branches,
it is similar to
mod_chroot,
but uses FreeBSD's specific system call -
jail
that is more secure than
chroot,
so, it is intended to run on
FreeBSD only.
Running Apache in jail can be tricky, this module
allows to run Apache in a secure jail prison easy,
without creating real jail environment containing copy of /lib, /libexec, /usr/lib, etc,
also
mod_jail makes it possible to change
securelevel into jail prison.
Module is redistributed under Apache 2.0 License.