This is the last version that handles both the 8.x and 9.x install
media formats. 

Qjail [ q = quick ] is a 4th generation wrapper for the basic chroot jail
system that includes security and performance enhancements. Plus a new level
of "user friendliness" enhancements dealing with deploying just a few jails or
large jail environments consisting of 100's of jails.

Qjail requires no knowledge of the jail command usage. It uses "nullfs" for
read-only system binaries, sharing one copy of them with all the jails.

Uses "mdconfig" to create sparse image jails. Sparse image jails provide a
method to limit the total disk space a jail can consume, while only occupying
the physical disk space of the sum size of the files in the image jail.

Ability to assign ip address with their network device name,
so aliases are auto created on jail start and auto removed on jail stop.

Ability to create "ZONE"s of identical qjail systems, each with their own
group of jails.

Ability to designate a portion of the jail name as a group prefix so the
command being executed will apply to only those jail names matching that prefix.

WWW: http://qjail.sourceforge.net/