1.4 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 https://www.gnu.org/software/hurd/ for more information about the GNU/Hurd in general, and https://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 https://www.debian.org/ports/#nonlinux for more information about these non-linux ports.