1.1. What is Debian GNU/kFreeBSD?
Debian GNU/kFreeBSD is a port of the Debian operating system that consists of the GNU userland, GNU C library, Debian package management and system tools, on top of the FreeBSD kernel. Think Debian GNU/Linux, with FreeBSD's kernel in place of Linux. All the benefits of your typical Debian system, along with a modern, robust FreeBSD kernel.
While there has not yet been an official Debian GNU/kFreeBSD release, snapshots of the latest stable branch are provided. For the Debian 5.0 'lenny' release snapshot, see the following wiki entry.