<s>
GNU	B-Operating_System
(	O
)	O
is	O
an	O
extensive	O
collection	O
of	O
free	B-Application
software	I-Application
(	O
383	O
packages	O
as	O
of	O
January	O
2022	O
)	O
,	O
which	O
can	O
be	O
used	O
as	O
an	O
operating	O
system	O
or	O
can	O
be	O
used	O
in	O
parts	O
with	O
other	O
operating	O
systems	O
.	O
</s>
<s>
The	O
use	O
of	O
the	O
completed	O
GNU	B-Operating_System
tools	O
led	O
to	O
the	O
family	O
of	O
operating	O
systems	O
popularly	O
known	O
as	O
Linux	B-Operating_System
.	O
</s>
<s>
Most	O
of	O
GNU	B-Operating_System
is	O
licensed	O
under	O
the	B-Application
GNU	I-Application
Project	I-Application
's	O
own	O
General	B-License
Public	I-License
License	I-License
(	O
GPL	B-License
)	O
.	O
</s>
<s>
GNU	B-Operating_System
is	O
also	O
the	O
project	O
within	O
which	O
the	O
free	B-Application
software	I-Application
concept	O
originated	O
.	O
</s>
<s>
Richard	O
Stallman	O
,	O
the	O
founder	O
of	O
the	O
project	O
,	O
views	O
GNU	B-Operating_System
as	O
a	O
"	O
technical	O
means	O
to	O
a	O
social	O
end	O
"	O
.	O
</s>
<s>
Relatedly	O
,	O
Lawrence	O
Lessig	O
states	O
in	O
his	O
introduction	O
to	O
the	O
second	O
edition	O
of	O
Stallman	O
's	O
book	O
Free	B-Application
Software	I-Application
,	O
Free	O
Society	O
that	O
in	O
it	O
Stallman	O
has	O
written	O
about	O
"	O
the	O
social	O
aspects	O
of	O
software	O
and	O
how	O
Free	B-Application
Software	I-Application
can	O
create	O
community	O
and	O
social	O
justice	O
"	O
.	O
</s>
<s>
GNU	B-Operating_System
is	O
a	O
recursive	O
acronym	O
for	O
"	O
GNU	B-Operating_System
's	I-Operating_System
Not	I-Operating_System
Unix	I-Operating_System
!	O
</s>
<s>
"	O
,	O
chosen	O
because	O
GNU	B-Operating_System
's	O
design	O
is	O
Unix-like	B-Operating_System
,	O
but	O
differs	O
from	O
Unix	B-Application
by	O
being	O
free	B-Application
software	I-Application
and	O
containing	O
no	O
Unix	B-Application
code	O
.	O
</s>
<s>
Stallman	O
chose	O
the	O
name	O
by	O
using	O
various	O
plays	O
on	O
words	O
,	O
including	O
the	O
song	O
The	O
Gnu	B-Operating_System
.	O
</s>
<s>
Development	O
of	O
the	B-Operating_System
GNU	I-Operating_System
operating	I-Operating_System
system	I-Operating_System
was	O
initiated	O
by	O
Richard	O
Stallman	O
while	O
he	O
worked	O
at	O
MIT	O
Artificial	O
Intelligence	O
Laboratory	O
.	O
</s>
<s>
It	O
was	O
called	O
the	B-Application
GNU	I-Application
Project	I-Application
,	O
and	O
was	O
publicly	O
announced	O
on	O
September	O
27	O
,	O
1983	O
,	O
on	O
the	O
net.unix-wizards	O
and	O
net.usoft	O
newsgroups	B-Application
by	O
Stallman	O
.	O
</s>
<s>
Software	O
development	O
began	O
on	O
January	O
5	O
,	O
1984	O
,	O
when	O
Stallman	O
quit	O
his	O
job	O
at	O
the	O
Lab	O
so	O
that	O
they	O
could	O
not	O
claim	O
ownership	O
or	O
interfere	O
with	O
distributing	O
GNU	B-Operating_System
components	O
as	O
free	B-Application
software	I-Application
.	O
</s>
<s>
The	O
goal	O
was	O
to	O
bring	O
a	O
completely	O
free	B-Application
software	I-Application
operating	O
system	O
into	O
existence	O
.	O
</s>
<s>
This	O
philosophy	O
was	O
published	O
as	O
the	B-Application
GNU	I-Application
Manifesto	I-Application
in	O
March	O
1985	O
.	O
</s>
<s>
Richard	O
Stallman	O
's	O
experience	O
with	O
the	O
Incompatible	B-Application
Timesharing	I-Application
System	I-Application
(	O
ITS	O
)	O
,	O
an	O
early	O
operating	O
system	O
written	O
in	O
assembly	B-Language
language	I-Language
that	O
became	O
obsolete	O
due	O
to	O
discontinuation	O
of	O
PDP-10	B-Device
,	O
the	O
computer	O
architecture	O
for	O
which	O
ITS	O
was	O
written	O
,	O
led	O
to	O
a	O
decision	O
that	O
a	O
portable	O
system	O
was	O
necessary	O
.	O
</s>
<s>
It	O
was	O
thus	O
decided	O
that	O
the	O
development	O
would	O
be	O
started	O
using	O
C	B-Language
and	O
Lisp	B-Language
as	O
system	O
programming	O
languages	O
,	O
and	O
that	O
GNU	B-Operating_System
would	O
be	O
compatible	O
with	O
Unix	B-Application
.	O
</s>
<s>
At	O
the	O
time	O
,	O
Unix	B-Application
was	O
already	O
a	O
popular	O
proprietary	B-Application
operating	O
system	O
.	O
</s>
<s>
The	O
design	O
of	O
Unix	B-Application
was	O
modular	O
,	O
so	O
it	O
could	O
be	O
reimplemented	O
piece	O
by	O
piece	O
.	O
</s>
<s>
Much	O
of	O
the	O
needed	O
software	O
had	O
to	O
be	O
written	O
from	O
scratch	O
,	O
but	O
existing	O
compatible	O
third-party	O
free	B-Application
software	I-Application
components	O
were	O
also	O
used	O
such	O
as	O
the	O
TeX	B-Application
typesetting	O
system	O
,	O
the	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
,	O
and	O
the	O
Mach	B-Operating_System
microkernel	I-Operating_System
that	O
forms	O
the	O
basis	O
of	O
the	O
GNU	B-Operating_System
Mach	I-Operating_System
core	O
of	O
GNU	B-Application
Hurd	I-Application
(	O
the	O
official	O
kernel	B-Operating_System
of	O
GNU	B-Operating_System
)	O
.	O
</s>
<s>
With	O
the	O
exception	O
of	O
the	O
aforementioned	O
third-party	O
components	O
,	O
most	O
of	O
GNU	B-Operating_System
has	O
been	O
written	O
by	O
volunteers	O
;	O
some	O
in	O
their	O
spare	O
time	O
,	O
some	O
paid	O
by	O
companies	O
,	O
educational	O
institutions	O
,	O
and	O
other	O
non-profit	O
organizations	O
.	O
</s>
<s>
In	O
October	O
1985	O
,	O
Stallman	O
set	O
up	O
the	B-Operating_System
Free	I-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
(	O
FSF	O
)	O
.	O
</s>
<s>
In	O
the	O
late	O
1980s	O
and	O
1990s	O
,	O
the	O
FSF	O
hired	O
software	O
developers	O
to	O
write	O
the	O
software	O
needed	O
for	O
GNU	B-Operating_System
.	O
</s>
<s>
As	O
GNU	B-Operating_System
gained	O
prominence	O
,	O
interested	O
businesses	O
began	O
contributing	O
to	O
development	O
or	O
selling	O
GNU	B-Operating_System
software	O
and	O
technical	O
support	O
.	O
</s>
<s>
The	O
system	O
's	O
basic	O
components	O
include	O
the	O
GNU	B-Application
Compiler	I-Application
Collection	I-Application
(	O
GCC	B-Application
)	O
,	O
the	O
GNU	B-Language
C	I-Language
library	I-Language
(	O
glibc	B-Language
)	O
,	O
and	O
GNU	B-Application
Core	I-Application
Utilities	I-Application
(	O
coreutils	B-Application
)	O
,	O
but	O
also	O
the	O
GNU	B-Language
Debugger	I-Language
(	O
GDB	B-Language
)	O
,	O
GNU	B-Application
Binary	I-Application
Utilities	I-Application
(	O
binutils	B-Application
)	O
,	O
and	O
the	O
GNU	B-Operating_System
Bash	I-Operating_System
shell	O
.	O
</s>
<s>
GNU	B-Operating_System
developers	O
have	O
contributed	O
to	O
Linux	B-Operating_System
ports	O
of	O
GNU	B-Operating_System
applications	O
and	O
utilities	O
,	O
which	O
are	O
now	O
also	O
widely	O
used	O
on	O
other	O
operating	O
systems	O
such	O
as	O
BSD	B-Operating_System
variants	O
,	O
Solaris	B-Application
and	O
macOS	B-Application
.	O
</s>
<s>
Many	O
GNU	B-Operating_System
programs	O
have	O
been	O
ported	O
to	O
other	O
operating	O
systems	O
,	O
including	O
proprietary	B-Application
platforms	O
such	O
as	O
Microsoft	B-Application
Windows	I-Application
and	O
macOS	B-Application
.	O
</s>
<s>
GNU	B-Operating_System
programs	O
have	O
been	O
shown	O
to	O
be	O
more	O
reliable	O
than	O
their	O
proprietary	B-Application
Unix	B-Application
counterparts	O
.	O
</s>
<s>
As	O
of	O
January	O
2022	O
,	O
there	O
are	O
a	O
total	O
of	O
459	O
GNU	B-Operating_System
packages	O
(	O
including	O
decommissioned	O
,	O
383	O
excluding	O
)	O
hosted	O
on	O
the	O
official	O
GNU	B-Operating_System
development	O
site	O
.	O
</s>
<s>
In	O
its	O
original	O
meaning	O
,	O
and	O
one	O
still	O
common	O
in	O
hardware	O
engineering	O
,	O
the	O
operating	O
system	O
is	O
a	O
basic	O
set	O
of	O
functions	O
to	O
control	O
the	O
hardware	O
and	O
manage	O
things	O
like	O
task	O
scheduling	O
and	O
system	B-Operating_System
calls	I-Operating_System
.	O
</s>
<s>
In	O
modern	O
terminology	O
used	O
by	O
software	O
developers	O
,	O
the	O
collection	O
of	O
these	O
functions	O
is	O
usually	O
referred	O
to	O
as	O
a	O
kernel	B-Operating_System
,	O
while	O
an	O
'	O
operating	O
system	O
 '	O
is	O
expected	O
to	O
have	O
a	O
more	O
extensive	O
set	O
of	O
programmes	O
.	O
</s>
<s>
The	B-Application
GNU	I-Application
project	I-Application
maintains	O
two	O
kernels	B-Operating_System
itself	O
,	O
allowing	O
the	O
creation	O
of	O
pure	O
GNU	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
,	O
but	O
the	O
GNU	B-Operating_System
toolchain	O
is	O
also	O
used	O
with	O
non-GNU	O
kernels	B-Operating_System
.	O
</s>
<s>
Due	O
to	O
the	O
two	O
different	O
definitions	O
of	O
the	O
term	O
'	O
operating	O
system	O
 '	O
,	O
there	O
is	O
an	O
ongoing	O
debate	B-Application
concerning	I-Application
the	I-Application
naming	I-Application
of	I-Application
distributions	I-Application
of	I-Application
GNU	I-Application
packages	I-Application
with	I-Application
a	I-Application
non-GNU	I-Application
kernel	I-Application
.	O
</s>
<s>
The	O
original	O
kernel	B-Operating_System
of	O
GNU	B-Application
Project	I-Application
is	O
the	O
GNU	B-Application
Hurd	I-Application
microkernel	B-Operating_System
,	O
which	O
was	O
the	O
original	O
focus	O
of	O
the	B-Operating_System
Free	I-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
(	O
FSF	O
)	O
.	O
</s>
<s>
With	O
the	O
April	O
30	O
,	O
2015	O
release	O
of	O
the	O
Debian	O
GNU/Hurd	B-Application
2015	O
distro	O
,	O
GNU	B-Operating_System
now	O
provides	O
all	O
required	O
components	O
to	O
assemble	O
an	O
operating	O
system	O
that	O
users	O
can	O
install	O
and	O
use	O
on	O
a	O
computer	O
.	O
</s>
<s>
However	O
,	O
the	B-Application
Hurd	I-Application
kernel	B-Operating_System
is	O
not	O
yet	O
considered	O
production-ready	O
but	O
rather	O
a	O
base	O
for	O
further	O
development	O
and	O
non-critical	O
application	O
usage	O
.	O
</s>
<s>
As	O
of	O
2012	O
,	O
a	O
fork	O
of	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
became	O
officially	O
part	O
of	O
the	B-Application
GNU	I-Application
Project	I-Application
in	O
the	O
form	O
of	O
Linux-libre	B-Application
,	O
a	O
variant	O
of	O
Linux	B-Operating_System
with	O
all	O
proprietary	B-Application
components	O
removed	O
.	O
</s>
<s>
The	B-Application
GNU	I-Application
Project	I-Application
has	O
endorsed	O
Linux-libre	B-Application
distributions	O
,	O
such	O
as	O
gNewSense	O
,	O
Trisquel	B-Application
and	O
Parabola	O
GNU/Linux	B-Application
-libre	O
.	O
</s>
<s>
Because	O
of	O
the	O
development	O
status	O
of	O
Hurd	B-Application
,	O
GNU	B-Operating_System
is	O
usually	O
paired	O
with	O
other	O
kernels	B-Operating_System
such	O
as	O
Linux	B-Operating_System
or	O
FreeBSD	B-Operating_System
.	O
</s>
<s>
Whether	O
the	O
combination	O
of	O
GNU	B-Operating_System
libraries	O
with	O
external	O
kernels	B-Operating_System
is	O
a	O
GNU	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
with	O
a	O
kernel	B-Operating_System
(	O
e.g.	O
</s>
<s>
GNU	B-Operating_System
with	O
Linux	B-Operating_System
)	O
,	O
because	O
the	O
GNU	B-Operating_System
collection	O
renders	O
the	O
kernel	B-Operating_System
into	O
a	O
usable	O
operating	O
system	O
as	O
understood	O
in	O
modern	O
software	O
development	O
,	O
or	O
whether	O
the	O
kernel	B-Operating_System
is	O
an	O
operating	O
system	O
unto	O
itself	O
with	O
a	O
GNU	B-Operating_System
layer	O
on	O
top	O
(	O
i.e.	O
</s>
<s>
Linux	B-Operating_System
with	O
GNU	B-Operating_System
)	O
,	O
because	O
the	O
kernel	B-Operating_System
can	O
operate	O
a	O
machine	O
without	O
GNU	B-Operating_System
,	O
is	O
a	O
matter	O
of	O
ongoing	O
debate	O
.	O
</s>
<s>
The	O
FSF	O
maintains	O
that	O
an	O
operating	O
system	O
built	O
using	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
and	O
GNU	B-Operating_System
tools	O
and	O
utilities	O
should	O
be	O
considered	O
a	O
variant	B-Application
of	I-Application
GNU	I-Application
,	O
and	O
promotes	O
the	O
term	O
GNU/Linux	B-Application
for	O
such	O
systems	O
(	O
leading	O
to	O
the	O
GNU/Linux	B-Application
naming	I-Application
controversy	I-Application
)	O
.	O
</s>
<s>
Notably	O
,	O
Debian	O
,	O
one	O
of	O
the	O
biggest	O
and	O
oldest	O
Linux	B-Application
distributions	I-Application
,	O
refers	O
to	O
itself	O
as	O
Debian	O
GNU/Linux	B-Application
.	O
</s>
<s>
The	B-Application
GNU	I-Application
Project	I-Application
recommends	O
that	O
contributors	O
assign	O
the	O
copyright	O
for	O
GNU	B-Operating_System
packages	O
to	O
the	B-Operating_System
Free	I-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
,	O
though	O
the	B-Operating_System
Free	I-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
considers	O
it	O
acceptable	O
to	O
release	O
small	O
changes	O
to	O
an	O
existing	O
project	O
to	O
the	O
public	O
domain	O
.	O
</s>
<s>
However	O
,	O
this	O
is	O
not	O
required	O
;	O
package	O
maintainers	O
may	O
retain	O
copyright	O
to	O
the	O
GNU	B-Operating_System
packages	O
they	O
maintain	O
,	O
though	O
since	O
only	O
the	O
copyright	O
holder	O
may	O
enforce	O
the	O
license	O
used	O
(	O
such	O
as	O
the	O
GNU	B-License
GPL	I-License
)	O
,	O
the	O
copyright	O
holder	O
in	O
this	O
case	O
enforces	O
it	O
rather	O
than	O
the	B-Operating_System
Free	I-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
.	O
</s>
<s>
For	O
the	O
development	O
of	O
needed	O
software	O
,	O
Stallman	O
wrote	O
a	O
license	O
called	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
(	O
first	O
called	O
Emacs	B-License
General	I-License
Public	I-License
License	I-License
)	O
,	O
with	O
the	O
goal	O
to	O
guarantee	O
users	O
freedom	O
to	O
share	O
and	O
change	O
free	B-Application
software	I-Application
.	O
</s>
<s>
Stallman	O
wrote	O
this	O
license	O
after	O
his	O
experience	O
with	O
James	O
Gosling	O
and	O
a	O
program	O
called	O
UniPress	O
,	O
over	O
a	O
controversy	O
around	O
software	O
code	O
use	O
in	O
the	O
GNU	B-Application
Emacs	I-Application
program	O
.	O
</s>
<s>
For	O
most	O
of	O
the	O
80s	O
,	O
each	O
GNU	B-Operating_System
package	O
had	O
its	O
own	O
license	O
:	O
the	O
Emacs	B-License
General	I-License
Public	I-License
License	I-License
,	O
the	O
GCC	B-Application
General	B-License
Public	I-License
License	I-License
,	O
etc	O
.	O
</s>
<s>
In	O
1989	O
,	O
FSF	O
published	O
a	O
single	O
license	O
they	O
could	O
use	O
for	O
all	O
their	O
software	O
,	O
and	O
which	O
could	O
be	O
used	O
by	O
non-GNU	O
projects	O
:	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
(	O
GPL	B-License
)	O
.	O
</s>
<s>
This	O
license	O
is	O
now	O
used	O
by	O
most	O
of	O
GNU	B-Operating_System
software	O
,	O
as	O
well	O
as	O
a	O
large	O
number	O
of	O
free	B-Application
software	I-Application
programs	O
that	O
are	O
not	O
part	O
of	O
the	B-Application
GNU	I-Application
Project	I-Application
;	O
it	O
also	O
historically	O
has	O
been	O
the	O
most	O
commonly	O
used	O
free	B-License
software	I-License
license	I-License
(	O
though	O
recently	O
challenged	O
by	O
the	B-License
MIT	I-License
license	I-License
)	O
.	O
</s>
<s>
This	O
idea	O
is	O
often	O
referred	O
to	O
as	O
copyleft	B-License
.	O
</s>
<s>
In	O
1991	O
,	O
the	O
GNU	B-Application
Lesser	I-Application
General	I-Application
Public	I-Application
License	I-Application
(	O
LGPL	B-Application
)	O
,	O
then	O
known	O
as	O
the	O
Library	B-Application
General	I-Application
Public	I-Application
License	I-Application
,	O
was	O
written	O
for	O
the	O
GNU	B-Language
C	I-Language
Library	I-Language
to	O
allow	O
it	O
to	O
be	O
linked	O
with	O
proprietary	B-Application
software	I-Application
.	O
</s>
<s>
1991	O
also	O
saw	O
the	O
release	O
of	O
version	O
2	O
of	O
the	O
GNU	B-License
GPL	I-License
.	O
</s>
<s>
The	O
GNU	B-Application
Free	I-Application
Documentation	I-Application
License	I-Application
(	O
FDL	O
)	O
,	O
for	O
documentation	O
,	O
followed	O
in	O
2000	O
.	O
</s>
<s>
The	O
GPL	B-License
and	O
LGPL	B-Application
were	O
revised	O
to	O
version	O
3	O
in	O
2007	O
,	O
adding	O
clauses	O
to	O
protect	O
users	O
against	O
hardware	O
restrictions	O
that	O
prevent	O
users	O
from	O
running	O
modified	O
software	O
on	O
their	O
own	O
devices	O
.	O
</s>
<s>
Besides	O
GNU	B-Operating_System
's	O
packages	O
,	O
the	B-Application
GNU	I-Application
Project	I-Application
's	O
licenses	O
are	O
used	O
by	O
many	O
unrelated	O
projects	O
,	O
such	O
as	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
,	O
often	O
used	O
with	O
GNU	B-Operating_System
software	O
.	O
</s>
<s>
A	O
minority	O
of	O
the	O
software	O
used	O
by	O
most	O
of	O
Linux	B-Application
distributions	I-Application
,	O
such	O
as	O
the	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
,	O
is	O
licensed	O
under	O
permissive	B-License
free	I-License
software	I-License
licenses	I-License
.	O
</s>
<s>
The	O
logo	O
for	O
GNU	B-Operating_System
is	O
a	O
gnu	B-Operating_System
head	O
.	O
</s>
<s>
It	O
appears	O
in	O
GNU	B-Operating_System
software	O
and	O
in	O
printed	O
and	O
electronic	O
documentation	O
for	O
the	B-Application
GNU	I-Application
Project	I-Application
,	O
and	O
is	O
also	O
used	O
in	O
Free	B-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
materials	O
.	O
</s>
<s>
It	O
was	O
created	O
by	O
the	B-Operating_System
Free	I-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
in	O
September	O
2013	O
in	O
order	O
to	O
commemorate	O
the	O
30th	O
anniversary	O
of	O
the	B-Application
GNU	I-Application
Project	I-Application
.	O
</s>
