Does Debian just do GNU/Linux?
Currently, Debian is only available for Linux, but with Debian GNU/Hurd and Debian on BSD kernels, we have started to offer non-Linux-based OSes as a development, server and desktop platform, too. However, these non-linux ports are not officially released yet. The oldest porting effort is Debian GNU/Hurd. The Hurd is a set of servers running on top of the GNU Mach microkernel. Together they build the base for the GNU operating system. Please see http://www.gnu.org/software/hurd/ for more information about the GNU/Hurd in general, and http://www.debian.org/ports/hurd/ for more information about Debian GNU/Hurd. A second effort is the port to a BSD kernel. People are working with both the NetBSD and the FreeBSD kernels. See http://www.debian.org/ports/#nonlinux for more information about these non-linux ports.