The term GNU/Linux is used by some to refer to an operating system where the Linux kernel is distributed with a GNU userland and GNU system software. Such distributions are the primary installed base of GNU packages and programs. The most notable official use of this term for a distribution is Debian GNU/Linux.
Debian GNU/kFreeBSD is an operating system released by the Debian project for i486-compatible computer architectures. It is a distribution of GNU with Debian package management and the kernel of FreeBSD. The k in kFreeBSD refers to the fact that only the kernel of the complete FreeBSD operating system is used. No official release of the operating system has yet been made. One such Debian GNU/kFreeBSD Live CD is Ging.
Debian GNU/NetBSD is an operating system released by the Debian project. It is a distribution of GNU with the NetBSD kernel. It is currently available for IA-32 and DEC Alpha architectures.
Gentoo/Alt is a project to provide an operating system based on a GNU userland managed by Portage to with different kernels including FreeBSD, OpenBSD and NetBSD.
Nexenta OS is the first distribution that combines the GNU userland and Debian's packaging and organisation with the OpenSolaris kernel. Nexenta OS is available for IA-32 and x86-64 based systems. Nexenta Systems, Inc initiated the project and sponsors its continued development.