Tinderbox is a package building system for FreeBSD ports, based on
official Portbuild scripts used on pointyhat building cluster.
Tinderbox was written by Joe Marcus Clarke.

You can define multiple jails (base system versions) and multiple
portstrees. The combination of jail and portstree is called a build.
A Tinderbox jail  is not what is understood as a jail in FreeBSD,
it is in fact a given world in a chroot. Tinderbox supports automatic
tracking of dependencies and only rebuilds packages that changed
since last run. Tinderbox has support for email notification  of
failed builds. Tinderbox also integrates well with ccache.

Tinderbox is designed to easily provide package sets of ports you
need, for platforms and architectures you need. Tinderbox is also
excellent tool for testing new ports and port upgrades, especially
for testing dependencies and packing lists. It's also useful for
testing ports on various releases of FreeBSD, since you can run
FreeBSD 6.X world as a jail on FreeBSD 7.X/8.X host.

WWW: http://tinderbox.marcuscom.com/