<s>
A	O
permissive	B-License
software	I-License
license	I-License
,	O
sometimes	O
also	O
called	O
BSD-like	O
or	O
BSD-style	B-Operating_System
license	I-Operating_System
,	O
is	O
a	O
free-software	B-License
license	I-License
which	O
instead	O
of	O
copyleft	B-License
protections	O
,	O
carries	O
only	O
minimal	O
restrictions	O
on	O
how	O
the	O
software	O
can	O
be	O
used	O
,	O
modified	O
,	O
and	O
redistributed	O
,	O
usually	O
including	O
a	O
warranty	O
disclaimer	O
.	O
</s>
<s>
Examples	O
include	O
the	O
GNU	B-License
All-permissive	I-License
License	I-License
,	O
MIT	B-License
License	I-License
,	O
BSD	B-Operating_System
licenses	I-Operating_System
,	O
Apple	B-License
Public	I-License
Source	I-License
License	I-License
and	O
Apache	B-Application
license	I-Application
.	O
</s>
<s>
the	O
most	O
popular	O
free-software	B-License
license	I-License
is	O
the	O
permissive	O
MIT	B-License
license	I-License
.	O
</s>
<s>
Public	O
domain	O
&	O
equivalents	O
Permissive	B-License
license	I-License
Copyleft	B-License
(	O
protective	O
license	B-License
)	O
Noncommercial	O
license	B-License
Proprietary	B-Application
license	I-Application
Trade	O
secret	O
Description	O
Grants	O
all	O
rights	O
Grants	O
use	O
rights	O
,	O
including	O
right	O
to	O
relicense	O
(	O
allows	O
proprietization	B-Application
,	O
license	B-License
compatibility	O
)	O
Grants	O
use	O
rights	O
,	O
forbids	O
proprietization	B-Application
Grants	O
rights	O
for	O
noncommercial	O
use	O
only	O
.	O
</s>
<s>
May	O
be	O
combined	O
with	O
copyleft	B-License
.	O
</s>
<s>
The	O
following	O
is	O
the	O
full	O
text	O
of	O
the	O
simple	O
GNU	B-License
All-permissive	I-License
License	I-License
:	O
</s>
<s>
The	O
Open	O
Source	O
Initiative	O
defines	O
a	O
permissive	B-License
software	I-License
license	I-License
as	O
a	O
"	O
non-copyleft	B-License
license	B-License
that	O
guarantees	O
the	O
freedoms	O
to	O
use	O
,	O
modify	O
and	O
redistribute	O
"	O
.	O
</s>
<s>
GitHub	B-Application
's	O
choosealicense	O
website	O
describes	O
the	O
permissive	O
MIT	B-License
license	I-License
as	O
"[letting]	O
people	O
do	O
anything	O
they	O
want	O
with	O
your	O
code	O
as	O
long	O
as	O
they	O
provide	O
attribution	O
back	O
to	O
you	O
and	O
do	O
n't	O
hold	O
you	O
liable.	O
"	O
</s>
<s>
California	O
Western	O
School	O
of	O
Law	O
's	O
newmediarights.com	O
defined	O
them	O
as	O
follows	O
:	O
"	O
The	O
'	O
BSD-like	O
'	O
licenses	O
such	O
as	O
the	O
BSD	B-Operating_System
,	O
MIT	B-License
and	O
Apache	B-Application
licenses	I-Application
are	O
extremely	O
permissive	O
,	O
requiring	O
little	O
more	O
than	O
attributing	O
the	O
original	O
portions	O
of	O
the	O
licensed	O
code	O
to	O
the	O
original	O
developers	O
in	O
your	O
own	O
code	O
and/or	O
documentation.	O
"	O
</s>
<s>
Copyleft	B-License
licenses	I-License
generally	O
require	O
the	O
reciprocal	O
publication	O
of	O
the	O
source	O
code	O
of	O
any	O
modified	O
versions	O
under	O
the	O
original	O
work	O
's	O
copyleft	B-License
license	I-License
.	O
</s>
<s>
Permissive	B-License
licenses	I-License
,	O
in	O
contrast	O
,	O
do	O
not	O
try	O
to	O
guarantee	O
that	O
modified	O
versions	O
of	O
the	O
software	O
will	O
remain	O
free	O
and	O
publicly	O
available	O
,	O
generally	O
requiring	O
only	O
that	O
the	O
original	O
copyright	O
notice	O
be	O
retained	O
.	O
</s>
<s>
As	O
a	O
result	O
,	O
derivative	O
works	O
,	O
or	O
future	O
versions	O
,	O
of	O
permissively-licensed	O
software	O
can	O
be	O
released	O
as	O
proprietary	B-Application
software	I-Application
.	O
</s>
<s>
Defining	O
how	O
liberal	O
a	O
license	B-License
is	O
,	O
however	O
,	O
is	O
not	O
something	O
easily	O
quantifiable	O
,	O
and	O
often	O
depends	O
on	O
the	O
goals	O
of	O
the	O
final	O
users	O
.	O
</s>
<s>
If	O
the	O
latter	O
are	O
developers	O
,	O
for	O
some	O
it	O
might	O
be	O
valuable	O
to	O
have	O
the	O
right	O
to	O
modify	O
and	O
exploit	O
source	O
code	O
written	O
by	O
others	O
and	O
possibly	O
incorporate	O
it	O
into	O
proprietary	B-Application
code	O
and	O
make	O
money	O
with	O
it	O
(	O
and	O
therefore	O
these	O
see	O
permissive	B-License
licenses	I-License
as	O
offering	O
them	O
a	O
"	O
right	O
"	O
)	O
,	O
while	O
for	O
other	O
developers	O
it	O
might	O
be	O
more	O
valuable	O
to	O
know	O
that	O
nobody	O
will	O
ever	O
capitalize	O
what	O
has	O
mostly	O
been	O
their	O
work	O
(	O
and	O
therefore	O
these	O
see	O
copyleft	B-License
licenses	I-License
as	O
offering	O
them	O
a	O
"	O
right	O
"	O
)	O
.	O
</s>
<s>
Furthermore	O
,	O
the	O
final	O
users	O
might	O
not	O
be	O
developers	O
at	O
all	O
,	O
and	O
in	O
this	O
case	O
copyleft	B-License
licenses	I-License
offer	O
them	O
the	O
everlasting	O
right	O
to	O
access	O
a	O
software	O
as	O
free	B-Application
software	I-Application
,	O
ensuring	O
that	O
it	O
will	O
never	O
become	O
closed	B-Application
source	I-Application
–	O
while	O
permissive	B-License
licenses	I-License
offer	O
no	O
rights	O
at	O
all	O
to	O
non-developer	O
final	O
users	O
,	O
and	O
software	O
released	O
with	O
a	O
permissive	B-License
license	I-License
could	O
theoretically	O
become	O
from	O
one	O
day	O
to	O
another	O
a	O
closed	B-Application
source	I-Application
malware	O
without	O
the	O
user	O
even	O
knowing	O
it	O
.	O
</s>
<s>
Permissive	B-License
licenses	I-License
offer	O
more	O
extensive	O
license	B-License
compatibility	O
than	O
copyleft	B-License
licenses	I-License
,	O
which	O
cannot	O
generally	O
be	O
freely	O
combined	O
and	O
mixed	O
,	O
because	O
their	O
reciprocity	O
requirements	O
conflict	O
with	O
each	O
other	O
.	O
</s>
<s>
However	O
,	O
permissive	B-License
licenses	I-License
are	O
not	O
actually	O
equivalent	O
to	O
releasing	O
a	O
work	O
into	O
the	O
public	O
domain	O
.	O
</s>
<s>
Permissive	B-License
licenses	I-License
often	O
do	O
stipulate	O
some	O
limited	O
requirements	O
,	O
such	O
as	O
that	O
the	O
original	O
authors	O
must	O
be	O
credited	O
(	O
attribution	O
)	O
.	O
</s>
<s>
Advocates	O
of	O
permissive	B-License
licenses	I-License
often	O
recommend	O
against	O
attempting	O
to	O
release	O
software	O
to	O
the	O
public	O
domain	O
,	O
on	O
the	O
grounds	O
that	O
this	O
can	O
be	O
legally	O
problematic	O
in	O
some	O
jurisdictions	O
.	O
</s>
<s>
Public-domain-equivalent	O
licenses	O
are	O
an	O
attempt	O
to	O
solve	O
this	O
problem	O
,	O
providing	O
a	O
fallback	O
permissive	B-License
license	I-License
for	O
cases	O
where	O
renunciation	O
of	O
copyright	O
is	O
not	O
legally	O
possible	O
,	O
and	O
sometimes	O
also	O
including	O
a	O
disclaimer	O
of	O
warranties	O
similar	O
to	O
most	O
permissive	B-License
licenses	I-License
.	O
</s>
<s>
In	O
general	O
permissive	B-License
licenses	I-License
have	O
good	O
license	B-License
compatibility	O
with	O
most	O
other	O
software	B-License
licenses	I-License
in	O
most	O
situations.xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx1	O
{{cite	O
web	O
|url	O
=	O
|title	O
=	O
Licence	O
Compatibility	O
|work	O
=	O
European	O
Union	O
Public	O
Licence	O
|publisher	O
=	O
joinup.ec.europa.eu	O
|quote	O
=	O
The	O
licenses	O
for	O
distributing	O
free	O
or	O
open	O
source	O
software	O
(	O
FOSS	B-License
)	O
are	O
divided	O
in	O
two	O
families	O
:	O
permissive	O
and	O
copyleft	B-License
.	O
</s>
<s>
Permissive	B-License
licenses	I-License
(	O
BSD	B-Operating_System
,	O
MIT	B-License
,	O
X11	B-License
,	O
Apache	B-Application
,	O
Zope	O
)	O
are	O
generally	O
compatible	O
and	O
interoperable	O
with	O
most	O
other	O
licenses	O
,	O
tolerating	O
to	O
merge	O
,	O
combine	O
or	O
improve	O
the	O
covered	O
code	O
and	O
to	O
re-distribute	O
it	O
under	O
many	O
licenses	O
(	O
including	O
non-free	O
or	O
“	O
proprietary	B-Application
”	O
)	O
.	O
</s>
<s>
Due	O
to	O
their	O
non-restrictiveness	O
,	O
most	O
permissive	B-License
software	I-License
licenses	I-License
are	O
even	O
compatible	O
with	O
copyleft	B-License
licenses	I-License
,	O
which	O
are	O
incompatible	O
with	O
most	O
other	O
licenses	O
.	O
</s>
<s>
Some	O
older	O
permissive	B-License
licenses	I-License
,	O
such	O
as	O
the	O
4-clause	O
BSD	B-Operating_System
license	I-Operating_System
,	O
the	O
PHP	B-Language
License	I-Language
,	O
and	O
the	O
OpenSSL	O
License	B-License
,	O
have	O
clauses	O
requiring	O
advertising	O
materials	O
to	O
credit	O
the	O
copyright	O
holder	O
,	O
which	O
made	O
them	O
incompatible	O
with	O
copyleft	B-License
licenses	I-License
.	O
</s>
<s>
Popular	O
modern	O
permissive	B-License
licenses	I-License
,	O
however	O
,	O
such	O
as	O
the	B-License
MIT	I-License
License	I-License
,	O
the	O
3-clause	O
BSD	B-Operating_System
license	I-Operating_System
and	O
the	O
zlib	B-License
license	I-License
,	O
do	O
n't	O
include	O
advertising	O
clauses	O
and	O
are	O
generally	O
compatible	O
with	O
copyleft	B-License
licenses	I-License
.	O
</s>
<s>
Examples	O
include	O
the	O
CDDL	B-Application
and	O
MsPL	B-License
.	O
</s>
<s>
However	O
such	O
restrictions	O
also	O
make	O
the	O
license	B-License
incompatible	O
with	O
permissive	O
free-software	B-License
licenses	I-License
.	O
</s>
<s>
While	O
they	O
have	O
been	O
in	O
use	O
since	O
the	O
mid-1980s	O
,	O
several	O
authors	O
noted	O
an	O
increase	O
in	O
the	O
popularity	O
of	O
permissive	B-License
licenses	I-License
during	O
the	O
2010s.Does	O
your	O
code	O
need	O
a	O
license	B-License
?	O
</s>
<s>
Posted	O
02	O
May	O
2013	O
by	O
Jason	O
Hibbets	O
"	O
Q	O
:	O
Are	O
there	O
software-development	O
companies	O
favoring	O
a	O
certain	O
open-source	O
license	B-License
over	O
another	O
?	O
</s>
<s>
the	B-License
MIT	I-License
License	I-License
,	O
a	O
permissive	B-License
license	I-License
,	O
is	O
the	O
most	O
popular	O
free	B-License
software	I-License
license	I-License
,	O
followed	O
by	O
GPLv2	O
.	O
</s>
<s>
Sometimes	O
the	O
word	O
"	O
permissive	O
"	O
is	O
considered	O
too	O
ambiguous	O
,	O
because	O
all	O
free	B-License
software	I-License
licenses	I-License
are	O
"	O
permissive	O
"	O
,	O
in	O
the	O
sense	O
that	O
they	O
all	O
allow	O
to	O
modify	O
and	O
redistribute	O
the	O
source	O
code	O
.	O
</s>
<s>
In	O
most	O
cases	O
the	O
real	O
opposition	O
is	O
between	O
copyleft	B-License
licenses	I-License
and	O
non-copyleft	B-License
ones	O
,	O
thus	O
some	O
authors	O
prefer	O
to	O
use	O
the	O
term	O
"	O
non-copyleft	B-License
"	O
instead	O
of	O
"	O
permissive	O
"	O
.	O
</s>
<s>
CopycenterCopycenter''	O
is	O
a	O
term	O
originally	O
used	O
to	O
explain	O
the	O
modified	B-Operating_System
BSD	I-Operating_System
license	I-Operating_System
,	O
a	O
permissive	O
free-software	B-License
license	I-License
.	O
</s>
<s>
The	O
term	O
was	O
presented	O
by	O
computer	O
scientist	O
and	O
Berkeley	B-Operating_System
Software	I-Operating_System
Distribution	I-Operating_System
(	O
BSD	B-Operating_System
)	O
contributor	O
Marshall	O
Kirk	O
McKusick	O
at	O
a	O
BSD	B-Operating_System
conference	O
in	O
1999	O
.	O
</s>
<s>
It	O
is	O
a	O
word	O
play	O
on	O
copyright	O
,	O
copyleft	B-License
and	O
copy	O
center	O
.	O
</s>
<s>
In	O
the	B-Operating_System
Free	I-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
's	O
guide	O
to	O
license	B-License
compatibility	O
and	O
relicensing	O
,	O
Richard	O
Stallman	O
defines	O
permissive	B-License
licenses	I-License
as	O
"	O
pushover	O
licenses	O
"	O
,	O
comparing	O
them	O
to	O
those	O
people	O
who	O
"	O
ca	O
n't	O
say	O
no	O
"	O
,	O
because	O
they	O
are	O
seen	O
as	O
granting	O
a	O
right	O
to	O
"	O
deny	O
freedom	O
to	O
others.	O
"	O
</s>
<s>
The	O
Foundation	O
recommends	O
pushover	O
licenses	O
only	O
for	O
small	O
programs	O
,	O
below	O
300	O
lines	O
of	O
code	O
,	O
where	O
"	O
the	O
benefits	O
provided	O
by	O
copyleft	B-License
are	O
usually	O
too	O
small	O
to	O
justify	O
the	O
inconvenience	O
of	O
making	O
sure	O
a	O
copy	O
of	O
the	O
license	B-License
always	O
accompanies	O
the	O
software	O
"	O
.	O
</s>
<s>
In	O
response	O
to	O
those	O
corporations	O
that	O
put	O
pressure	O
on	O
developers	O
to	O
move	O
away	O
from	O
copyleft	B-License
licenses	I-License
in	O
favour	O
of	O
permissive	O
ones	O
,	O
some	O
developers	O
have	O
coined	O
the	O
term	O
"	O
cuck	O
license	B-License
"	O
(	O
precisely	O
in	O
analogy	O
to	O
being	O
cuckolded	O
)	O
,	O
as	O
they	O
perceive	O
that	O
corporations	O
want	O
to	O
benefit	O
from	O
collaborative	O
work	O
and	O
privatize	O
profits	O
without	O
giving	O
anything	O
back	O
.	O
</s>
