<s>
BSD	B-Operating_System
licenses	O
are	O
a	O
family	O
of	O
permissive	B-License
free	I-License
software	I-License
licenses	I-License
,	O
imposing	O
minimal	O
restrictions	O
on	O
the	O
use	O
and	O
distribution	O
of	O
covered	O
software	O
.	O
</s>
<s>
This	O
is	O
in	O
contrast	O
to	O
copyleft	B-License
licenses	I-License
,	O
which	O
have	O
share-alike	O
requirements	O
.	O
</s>
<s>
The	O
original	O
BSD	B-Operating_System
license	O
was	O
used	O
for	O
its	O
namesake	O
,	O
the	O
Berkeley	B-Operating_System
Software	I-Operating_System
Distribution	I-Operating_System
(	O
BSD	B-Operating_System
)	O
,	O
a	O
Unix-like	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
.	O
</s>
<s>
The	O
original	O
version	O
has	O
since	O
been	O
revised	O
,	O
and	O
its	O
descendants	O
are	O
referred	O
to	O
as	O
modified	O
BSD	B-Operating_System
licenses	O
.	O
</s>
<s>
BSD	B-Operating_System
is	O
both	O
a	O
license	O
and	O
a	O
class	O
of	O
license	O
(	O
generally	O
referred	O
to	O
as	O
BSD-like	O
)	O
.	O
</s>
<s>
The	O
modified	O
BSD	B-Operating_System
license	O
(	O
in	O
wide	O
use	O
today	O
)	O
is	O
very	O
similar	O
to	O
the	O
license	O
originally	O
used	O
for	O
the	O
BSD	B-Operating_System
version	O
of	O
Unix	B-Application
.	O
</s>
<s>
The	O
BSD	B-Operating_System
license	O
is	O
a	O
simple	O
license	O
that	O
merely	O
requires	O
that	O
all	O
code	O
retain	O
the	O
BSD	B-Operating_System
license	O
notice	O
if	O
redistributed	O
in	O
source	O
code	O
format	O
,	O
or	O
reproduce	O
the	O
notice	O
if	O
redistributed	O
in	O
binary	O
format	O
.	O
</s>
<s>
The	O
BSD	B-Operating_System
license	O
(	O
unlike	O
some	O
other	O
licenses	O
e.g.	O
</s>
<s>
GPL	B-License
)	O
does	O
not	O
require	O
that	O
source	O
code	O
be	O
distributed	O
at	O
all	O
.	O
</s>
<s>
In	O
addition	O
to	O
the	O
original	O
(	O
4-clause	O
)	O
license	O
used	O
for	O
BSD	B-Operating_System
,	O
several	O
derivative	O
licenses	O
have	O
emerged	O
that	O
are	O
also	O
commonly	O
referred	O
to	O
as	O
a	O
"	O
BSD	B-Operating_System
license	O
"	O
.	O
</s>
<s>
Today	O
,	O
the	O
typical	O
BSD	B-Operating_System
license	O
is	O
the	O
3-clause	O
version	O
,	O
which	O
is	O
revised	O
from	O
the	O
original	O
4-clause	O
version	O
.	O
</s>
<s>
In	O
all	O
BSD	B-Operating_System
licenses	O
as	O
following	O
,	O
<year>	O
is	O
the	O
year	O
of	O
the	O
copyright	O
.	O
</s>
<s>
As	O
published	O
in	O
BSD	B-Operating_System
,	O
<copyright holder>	O
is	O
"	O
Regents	O
of	O
the	O
University	O
of	O
California	O
"	O
.	O
</s>
<s>
Some	O
releases	O
of	O
BSD	B-Operating_System
prior	O
to	O
the	O
adoption	O
of	O
the	O
4-clause	O
BSD	B-Operating_System
license	O
used	O
a	O
license	O
that	O
is	O
clearly	O
ancestral	O
to	O
the	O
4-clause	O
BSD	B-Operating_System
license	O
.	O
</s>
<s>
The	O
original	O
BSD	B-Operating_System
license	O
contained	O
a	O
clause	O
not	O
found	O
in	O
later	O
licenses	O
,	O
known	O
as	O
the	O
"	O
advertising	O
clause	O
"	O
.	O
</s>
<s>
This	O
clause	O
eventually	O
became	O
controversial	O
,	O
as	O
it	O
required	O
authors	O
of	O
all	O
works	O
deriving	O
from	O
a	O
BSD-licensed	O
work	O
to	O
include	O
an	O
acknowledgment	O
of	O
the	O
original	O
source	O
in	O
all	O
advertising	O
material	O
.	O
</s>
<s>
In	O
arguing	O
against	O
it	O
,	O
Richard	O
Stallman	O
has	O
stated	O
that	O
he	O
counted	O
75	O
such	O
acknowledgments	O
in	O
a	O
1997	O
version	O
of	O
NetBSD	B-Device
.	O
</s>
<s>
In	O
addition	O
,	O
the	O
clause	O
presented	O
a	O
legal	O
problem	O
for	O
those	O
wishing	O
to	O
publish	O
BSD-licensed	O
software	O
which	O
relies	O
upon	O
separate	O
programs	O
using	O
the	O
GNU	B-License
GPL	I-License
:	O
the	O
advertising	O
clause	O
is	O
incompatible	O
with	O
the	O
GPL	B-License
,	O
which	O
does	O
not	O
allow	O
the	O
addition	O
of	O
restrictions	O
beyond	O
those	O
it	O
already	O
imposes	O
;	O
because	O
of	O
this	O
,	O
the	O
GPL	B-License
's	O
publisher	O
,	O
the	B-Operating_System
Free	I-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
,	O
recommends	O
developers	O
not	O
use	O
the	O
license	O
,	O
though	O
it	O
states	O
there	O
is	O
no	O
reason	O
not	O
to	O
use	O
software	O
already	O
using	O
it	O
.	O
</s>
<s>
The	O
advertising	O
clause	O
was	O
removed	O
from	O
the	O
license	O
text	O
in	O
the	O
official	O
BSD	B-Operating_System
license	O
on	O
July	O
22	O
,	O
1999	O
,	O
by	O
William	O
Hoskins	O
,	O
Director	O
of	O
the	O
Office	O
of	O
Technology	O
Licensing	O
for	O
UC	O
Berkeley	O
.	O
</s>
<s>
Other	O
BSD	B-Operating_System
distributions	O
removed	O
the	O
clause	O
,	O
but	O
many	O
similar	O
clauses	O
remain	O
in	O
BSD-derived	O
code	O
from	O
other	O
sources	O
,	O
and	O
unrelated	O
code	O
using	O
a	O
derived	O
license	O
.	O
</s>
<s>
While	O
the	O
original	O
license	O
is	O
sometimes	O
referred	O
to	O
as	O
the	O
"	O
BSD-old	O
"	O
,	O
the	O
resulting	O
3-clause	O
version	O
is	O
sometimes	O
referred	O
to	O
by	O
"	O
BSD-new.	O
"	O
</s>
<s>
Other	O
names	O
include	O
new	O
BSD	B-Operating_System
,	O
"	O
revised	O
BSD	B-Operating_System
"	O
,	O
"	O
BSD-3	O
"	O
,	O
or	O
"	O
3-clause	O
BSD	B-Operating_System
"	O
.	O
</s>
<s>
This	O
version	O
has	O
been	O
vetted	O
as	O
an	O
Open	O
source	O
license	O
by	O
the	O
OSI	O
as	O
"	O
The	O
BSD	B-Operating_System
License	O
"	O
.	O
</s>
<s>
The	B-Operating_System
Free	I-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
,	O
which	O
refers	O
to	O
the	O
license	O
as	O
the	O
"	O
Modified	O
BSD	B-Operating_System
License	O
"	O
,	O
states	O
that	O
it	O
is	O
compatible	O
with	O
the	O
GNU	B-License
GPL	I-License
.	O
</s>
<s>
not	O
simply	O
referring	O
to	O
it	O
as	O
"	O
a	O
BSD	B-Operating_System
license	O
"	O
or	O
"	O
BSD-style	O
"	O
)	O
to	O
avoid	O
confusion	O
with	O
the	O
original	O
BSD	B-Operating_System
license	O
.	O
</s>
<s>
An	O
even	O
more	O
simplified	O
version	O
has	O
come	O
into	O
use	O
,	O
primarily	O
known	O
for	O
its	O
usage	O
in	O
FreeBSD	B-Operating_System
.	O
</s>
<s>
The	O
primary	O
difference	O
between	O
it	O
and	O
the	O
New	O
BSD	B-Operating_System
(	O
3-clause	O
)	O
License	O
is	O
that	O
it	O
omits	O
the	O
non-endorsement	O
clause	O
.	O
</s>
<s>
The	O
FreeBSD	B-Operating_System
version	O
of	O
the	O
license	O
also	O
adds	O
a	O
further	O
disclaimer	O
about	O
views	O
and	O
opinions	O
expressed	O
in	O
the	O
software	O
,	O
though	O
this	O
is	O
not	O
commonly	O
included	O
by	O
other	O
projects	O
.	O
</s>
<s>
The	B-Operating_System
Free	I-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
,	O
which	O
refers	O
to	O
the	O
license	O
as	O
the	O
FreeBSD	B-Operating_System
License	O
,	O
states	O
that	O
it	O
is	O
compatible	O
with	O
the	O
GNU	B-License
GPL	I-License
.	O
</s>
<s>
not	O
simply	O
referring	O
to	O
it	O
as	O
"	O
a	O
BSD	B-Operating_System
license	O
"	O
or	O
"	O
BSD-style	O
"	O
)	O
,	O
as	O
it	O
does	O
with	O
the	O
modified/new	O
BSD	B-Operating_System
license	O
,	O
to	O
avoid	O
confusion	O
with	O
the	O
original	O
BSD	B-Operating_System
license	O
.	O
</s>
<s>
Other	O
projects	O
,	O
such	O
as	O
NetBSD	B-Device
,	O
use	O
a	O
similar	O
2-clause	O
license	O
.	O
</s>
<s>
The	O
ISC	B-License
license	I-License
without	O
the	O
'	O
and/or	O
'	O
wording	O
is	O
functionally	O
equivalent	O
,	O
and	O
endorsed	O
by	O
the	O
OpenBSD	B-Operating_System
project	I-Operating_System
as	O
a	O
license	O
template	O
for	O
new	O
contributions	O
.	O
</s>
<s>
The	O
BSD	B-Operating_System
0-clause	O
license	O
goes	O
further	O
than	O
the	O
2-clause	O
license	O
by	O
dropping	O
the	O
requirements	O
to	O
include	O
the	O
copyright	O
notice	O
,	O
license	O
text	O
,	O
or	O
disclaimer	O
in	O
either	O
source	O
or	O
binary	O
forms	O
.	O
</s>
<s>
It	O
is	O
known	O
as	O
"	O
0BSD	O
"	O
,	O
"	O
Zero-Clause	O
BSD	B-Operating_System
"	O
,	O
or	O
"	O
Free	O
Public	O
License	O
1.0.0	O
"	O
.	O
</s>
<s>
It	O
was	O
first	O
used	O
by	O
Rob	O
Landley	O
in	O
Toybox	B-Language
.	O
</s>
<s>
The	O
SPDX	O
License	O
List	O
contains	O
extra	O
BSD	B-Operating_System
license	O
variations	O
.	O
</s>
<s>
,	O
a	O
variation	O
of	O
BSD-2-Clause	O
with	O
a	O
patent	O
grant	O
.	O
</s>
<s>
,	O
a	O
variation	O
of	O
BSD-3-Clause	O
that	O
adds	O
a	O
disclaimer	O
that	O
a	O
piece	O
of	O
software	O
is	O
not	O
designed	O
for	O
use	O
in	O
a	O
nuclear	O
facility	O
.	O
</s>
<s>
The	O
FreeBSD	B-Operating_System
project	I-Operating_System
argues	O
on	O
the	O
advantages	O
of	O
BSD-style	B-License
licenses	I-License
for	O
companies	O
and	O
commercial	B-Application
use-cases	O
due	O
to	O
their	O
license	O
compatibility	O
with	O
proprietary	B-Application
licenses	I-Application
and	O
general	O
flexibility	O
,	O
stating	O
that	O
the	O
BSD-style	B-License
licenses	I-License
place	O
only	O
"	O
minimal	O
restrictions	O
on	O
future	O
behavior	O
"	O
and	O
are	O
not	O
"	O
legal	O
time-bombs	O
"	O
,	O
unlike	O
copyleft	B-License
licenses	I-License
.	O
</s>
<s>
The	O
BSD	B-Operating_System
License	O
allows	O
proprietary	B-Application
use	O
and	O
allows	O
the	O
software	O
released	O
under	O
the	O
license	O
to	O
be	O
incorporated	O
into	O
proprietary	B-Application
products	O
.	O
</s>
<s>
Works	O
based	O
on	O
the	O
material	O
may	O
be	O
released	O
under	O
a	O
proprietary	B-Application
license	I-Application
as	O
closed	B-Application
source	I-Application
software	I-Application
,	O
allowing	O
usual	O
commercial	B-Application
usages	O
under	O
them	O
.	O
</s>
<s>
The	O
3-clause	O
BSD	B-Operating_System
license	O
,	O
like	O
most	O
permissive	B-License
licenses	I-License
,	O
is	O
compatible	O
with	O
almost	O
all	O
FOSS	B-License
licenses	O
(	O
and	O
as	O
well	O
proprietary	B-Application
licenses	I-Application
)	O
.	O
</s>
<s>
Two	O
variants	O
of	O
the	O
license	O
,	O
the	O
New	O
BSD	B-Operating_System
License/Modified	O
BSD	B-Operating_System
License	O
(	O
3-clause	O
)	O
,	O
and	O
the	O
Simplified	O
BSD	B-Operating_System
License/FreeBSD	O
License	O
(	O
2-clause	O
)	O
have	O
been	O
verified	O
as	O
GPL-compatible	O
free	B-License
software	I-License
licenses	I-License
by	O
the	B-Operating_System
Free	I-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
,	O
and	O
have	O
been	O
vetted	O
as	O
open	O
source	O
licenses	O
by	O
the	O
Open	O
Source	O
Initiative	O
.	O
</s>
<s>
The	O
original	O
,	O
4-clause	O
BSD	B-Operating_System
license	O
has	O
not	O
been	O
accepted	O
as	O
an	O
open	O
source	O
license	O
and	O
,	O
although	O
the	O
original	O
is	O
considered	O
to	O
be	O
a	O
free	B-License
software	I-License
license	I-License
by	O
the	O
FSF	O
,	O
the	O
FSF	O
does	O
not	O
consider	O
it	O
to	O
be	O
compatible	O
with	O
the	O
GPL	B-License
due	O
to	O
the	O
advertising	O
clause	O
.	O
</s>
<s>
The	O
BSD	B-Operating_System
license	O
family	O
is	O
one	O
of	O
the	O
oldest	O
and	O
most	O
broadly	O
used	O
license	O
families	O
in	O
the	O
Free	B-License
and	I-License
open-source	I-License
software	I-License
ecosystem	O
.	O
</s>
<s>
Also	O
,	O
many	O
new	O
licenses	O
were	O
derived	O
or	O
inspired	O
by	O
the	O
BSD	B-Operating_System
licenses	O
.	O
</s>
<s>
Many	O
FOSS	B-License
software	O
projects	O
use	O
a	O
BSD	B-Operating_System
license	O
,	O
for	O
instance	O
the	O
BSD	B-Operating_System
OS	O
family	O
(	O
FreeBSD	B-Operating_System
etc	O
.	O
</s>
<s>
)	O
,	O
Google	B-Application
's	I-Application
Bionic	B-Application
or	O
Toybox	B-Language
.	O
</s>
<s>
the	O
BSD	B-Operating_System
3-clause	O
license	O
ranked	O
in	O
popularity	O
number	O
five	O
according	O
to	O
Black	O
Duck	O
Software	O
and	O
sixth	O
according	O
to	O
GitHub	B-Application
data	O
.	O
</s>
