Editing GNU (section)

==GNU as an operating system==
{{Main|GNU variants}}

In its [[History of operating systems#Background|original meaning]], and one still common in hardware engineering, the operating system is a basic set of functions to control the hardware and manage things like [[task scheduler|task scheduling]] and [[system call]]s. In modern terminology used by software developers, the collection of these functions is usually referred to as a [[operating system kernel|kernel]], while an 'operating system' is expected to have a more extensive set of programs. The GNU project maintains two kernels itself, allowing the creation of pure GNU operating systems, but the GNU toolchain is also used with non-GNU kernels. Due to the two different definitions of the term 'operating system', there is an ongoing [[GNU/Linux naming controversy|debate concerning the naming of distributions of GNU packages with a non-GNU kernel]]. (See below.)

=== With kernels maintained by GNU and FSF ===
[[File:Parabola12.png|thumb|[[Parabola GNU/Linux-libre]], an example of an FSF approved distribution that uses a [[rolling release]] model]]

==== GNU Hurd ====
The original kernel of GNU Project is the [[GNU Hurd]] (together with the [[GNU Mach]] microkernel), which was the original focus of the [[Free Software Foundation]] (FSF).<ref name = "handbookonopensource" /><ref name = computerworld>Vaughan-Nichols, Steven J. "[https://www.computerworld.com/s/article/9131178/Opinion_The_top_10_operating_system_stinkers Opinion: The top 10 operating system stinkers]", ''[[Computerworld]]'', April 9, 2009: "... after more than 25 years in development, GNU remains incomplete: its kernel, Hurd, has never really made it out of the starting blocks. ... Almost no one has actually been able to use the OS; it's really more a set of ideas than an operating system."</ref><ref name= Hillesley>{{Citation | last = Hillesley | first = Richard | newspaper = The H | url = https://www.h-online.com/open/features/GNU-HURD-Altered-visions-and-lost-promise-1030942.html | edition = online | title = GNU HURD: Altered visions and lost promise | date = June 30, 2010 | page = [https://www.h-online.com/open/features/GNU-HURD-Altered-visions-and-lost-promise-1030942.html?page=3 3] | quote = Nearly twenty years later the HURD has still to reach maturity, and has never achieved production quality. ... Some of us are still wishing and hoping for the real deal, a GNU operating system with a GNU kernel.}}</ref><ref>{{cite book |last1=Lessig |first1=Lawrence |title=The Future of Ideas: The Fate of the Commons in a Connected World |date=2001 |publisher=Random House |isbn=978-0-375-50578-2 |url=https://archive.org/details/futureo_les_2001_00_1645|url-access=registration |page=[https://archive.org/details/futureo_les_2001_00_1645/page/54 54] |quote=He had mixed all of the ingredients needed for an operating system to function, but he was missing the core.}}</ref>

With the April 30, 2015 release of the Debian GNU/Hurd 2015 distro,<ref>{{Cite web|url=https://www.phoronix.com/scan.php?page=news_item&px=Debian-GNU-Hurd-2015|title=Debian GNU/Hurd 2015 Released – Phoronix|website=www.phoronix.com|access-date=2016-03-24}}</ref><ref>{{Cite web|url=https://lists.debian.org/debian-hurd/2015/04/msg00047.html|title=Debian GNU/Hurd 2015 released!|website=lists.debian.org|access-date=2016-03-24}}</ref> GNU now provides all required components to assemble an operating system that users can install and use on a computer.<ref name="status">{{Cite web|url=https://www.gnu.org/software/hurd/hurd/status.html|title=status|website=www.gnu.org|access-date=2016-03-24}}</ref><ref>{{Cite web|url=https://www.debian.org/ports/hurd/|title=Debian – Debian GNU/Hurd|website=www.debian.org|access-date=2016-03-24}}</ref><ref>{{Cite web|url=https://www.debian.org/ports/hurd/hurd-install|title=Debian – Debian GNU/Hurd – Configuration|website=www.debian.org|access-date=2016-03-24}}</ref>

However, the Hurd kernel is not yet considered production-ready but rather a base for further development and non-critical application usage.<ref>{{Citation | url=https://www.gnu.org/software/hurd/hurd/status.html | publisher = Free Software Foundation | title = Status | access-date = 2017-04-24 | date = 2015-05-03}}</ref><ref name="status" />

==== Linux-libre ====
In 2012, a fork of the [[Linux kernel]] became officially part of the GNU Project in the form of [[Linux-libre]], a variant of Linux with all proprietary components removed.<ref>{{cite web | url= https://directory.fsf.org/wiki/GNU_Linux-libre |title = GNU Linux-libre | date = 2012-12-17 | access-date = 2013-02-09}}</ref>
The GNU Project has endorsed Linux-libre distributions, such as [[Trisquel]], [[Parabola GNU/Linux-libre]], [[PureOS]] and [[GNU Guix System]].<ref>{{Citation | contribution-url = https://www.gnu.org/distros/free-distros.html | contribution = List of Free GNU/Linux Distributions | title = GNU Project | publisher = Free Software Foundation (FSF)}}.</ref>

=== With non-GNU kernels ===
[[File:Trisquel 11.0.png|thumb|[[Trisquel]], an example of an [[List of GNU/Linux distributions endorsed by the Free Software Foundation|FSF approved distribution]]]]

Because of the development status of Hurd, GNU is usually paired with other kernels such as [[Linux]]<ref>{{Citation | chapter-url = https://oreilly.com/openbook/debian/book/ch01_02.html |title= Debian open book | chapter = 1.2 What is Linux? |publisher = O'Reilly |date=1991-10-05 |access-date = 2012-09-22}}</ref><ref>{{Citation | edition = 12.4 | contribution-url = https://help.ubuntu.com/lts/installation-guide/armhf/ch01s03.html | contribution = What is GNU/Linux? | publisher = Canonical | title = Ubuntu Installation Guide | access-date = 2015-06-22 | archive-date = June 21, 2015 | archive-url = https://web.archive.org/web/20150621214422/https://help.ubuntu.com/lts/installation-guide/armhf/ch01s03.html | url-status = dead }}</ref> or [[FreeBSD]].<ref>{{cite book|url=https://books.google.com/books?id=CHkHNChvPqIC |title=Open Source Software: Implementation and Management| page = 129| isbn= 978-1-55558320-0| last1 = Kavanagh | first1 = Paul| date = 2004-07-26|publisher=Elsevier }}</ref> Whether the combination of GNU libraries with external kernels is a GNU operating system with a kernel (e.g. GNU with Linux), because the GNU collection renders the kernel into a usable operating system as understood in modern software development, or whether the kernel is an operating system unto itself with a GNU layer on top (i.e. Linux with GNU), because the kernel can operate a machine without GNU, is a matter of ongoing debate. The FSF maintains that an operating system built using the [[Linux kernel]] and GNU tools and utilities should be considered a [[GNU variants|variant of GNU]], and promotes the term ''GNU/Linux'' for such systems (leading to the [[GNU/Linux naming controversy]]). This view is not exclusive to the FSF.<ref>{{cite newsgroup | url = https://groups.google.com/group/comp.os.linux.misc/msg/1241a2919efc4bc3 | title = Linux is a GNU system and the DWARF support | newsgroup = comp.os.linux.misc | date = 8 September 1994 | first = Matt | last = Welsh | access-date = 3 February 2008 | quote = RMS's idea (which I have heard first-hand) is that Linux systems should be considered GNU systems with Linux as the kernel.}}</ref><ref>{{cite web|last=Proffitt |first = Brian |url=https://www.itworld.com/it-managementstrategy/285750/debian-gnulinux-seeks-alignment-free-software-foundation | title =Debian GNU/Linux seeks alignment with Free Software Foundation | work =ITworld | date =2012-07-12 |access-date= 2012-09-22}}</ref><ref>{{cite web|url= https://www.tldp.org/LDP/sag/html/gnu-or-not.html |title= 1.1. Linux or GNU/Linux, that is the question | work = SAG | publisher= TLDP | access-date = 2012-09-22}}</ref><ref>{{Cite web|url=https://ccm.net/faq/478-gnu-operating-system|title=GNU Operating System – CCM FAQ|website=CCM|language=en|access-date=2018-04-08|quote=GNU is an operating system that offers a set of free open source programs.|archive-date=December 15, 2019|archive-url=https://web.archive.org/web/20191215074114/https://ccm.net/faq/478-gnu-operating-system|url-status=dead}}</ref><ref>{{Cite web|url=https://www.snom.com/footer/source-code-gpl-open-source/|title=Source Code & GPL Open Source|last=Snom Technology|website=www.snom.com|language=en|access-date=2018-04-08|quote=Variants of the GNU operating system, which use the kernel Linux, are now widely used; though these systems are often referred to as "Linux", they are more accurately called "GNU/Linux systems".|archive-date=April 9, 2018|archive-url=https://web.archive.org/web/20180409044219/https://www.snom.com/footer/source-code-gpl-open-source/|url-status=dead}}</ref> Notably, [[Debian]], one of the biggest and oldest Linux distributions, refers to itself as ''Debian GNU/Linux''.<ref>{{cite web| url = https://www.debian.org/doc/manuals/debian-faq/basic-defs.en.html#whatisdebian| title = Chapter 1. Definitions and overview}}</ref>