<s>
The	B-License
MIT	I-License
License	I-License
is	O
a	O
permissive	B-License
free	I-License
software	I-License
license	I-License
originating	O
at	O
the	O
Massachusetts	O
Institute	O
of	O
Technology	O
(	O
MIT	O
)	O
in	O
the	O
late	O
1980s	O
.	O
</s>
<s>
As	O
a	O
permissive	B-License
license	I-License
,	O
it	O
puts	O
only	O
very	O
limited	O
restriction	O
on	O
reuse	O
and	O
has	O
,	O
therefore	O
,	O
high	O
license	O
compatibility	O
.	O
</s>
<s>
Unlike	O
copyleft	B-License
software	O
licenses	O
,	O
the	B-License
MIT	I-License
License	I-License
also	O
permits	O
reuse	O
within	O
proprietary	B-Application
software	I-Application
,	O
provided	O
that	O
all	O
copies	O
of	O
the	O
software	O
or	O
its	O
substantial	O
portions	O
include	O
a	O
copy	O
of	O
the	O
terms	O
of	O
the	B-License
MIT	I-License
License	I-License
and	O
also	O
a	O
copyright	O
notice	O
.	O
</s>
<s>
,	O
the	B-License
MIT	I-License
License	I-License
was	O
the	O
most	O
popular	O
software	O
license	O
found	O
in	O
one	O
analysis	O
,	O
continuing	O
from	O
reports	O
in	O
2015	O
that	O
the	B-License
MIT	I-License
License	I-License
was	O
the	O
most	O
popular	O
software	O
license	O
on	O
GitHub	B-Application
.	O
</s>
<s>
Notable	O
projects	O
that	O
use	O
the	B-License
MIT	I-License
License	I-License
include	O
the	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
,	O
Ruby	B-Application
on	I-Application
Rails	I-Application
,	O
Nim	B-Application
,	O
Node.js	B-Language
,	O
Lua	B-Language
,	O
and	O
jQuery	B-Language
.	O
</s>
<s>
Notable	O
companies	O
using	O
the	B-License
MIT	I-License
License	I-License
include	O
Microsoft	O
(	O
.NET	B-Application
)	O
,	O
Google	B-Application
(	O
Angular	B-Language
)	O
,	O
and	O
Meta	O
(	O
React	O
)	O
.	O
</s>
<s>
The	B-License
MIT	I-License
License	I-License
has	O
the	O
identifier	O
MIT	O
in	O
the	O
SPDX	O
License	O
List	O
.	O
</s>
<s>
It	O
is	O
also	O
known	O
as	O
the	O
"	O
Expat	B-License
License	I-License
"	O
.	O
</s>
<s>
The	O
X11	B-License
License	I-License
,	O
also	O
known	O
as	O
the	O
MIT/X	B-License
Consortium	I-License
License	I-License
,	O
is	O
a	O
variation	O
on	O
the	B-License
MIT	I-License
license	I-License
,	O
most	O
known	O
for	O
its	O
usage	O
by	O
the	O
X	B-Operating_System
Consortium	O
.	O
</s>
<s>
It	O
has	O
the	O
identifier	O
X11	B-Operating_System
in	O
the	O
SPDX	O
License	O
List	O
.	O
</s>
<s>
It	O
differs	O
from	O
the	B-License
MIT	I-License
License	I-License
mainly	O
by	O
an	O
additional	O
clause	O
restricting	O
use	O
of	O
the	O
copyright	O
holders	O
 '	O
name	O
for	O
advertisement	O
.	O
</s>
<s>
The	O
FPA	O
License	O
,	O
a	O
less-permissive	O
variation	O
of	O
the	B-License
MIT	I-License
License	I-License
,	O
has	O
the	O
identifier	O
FPA	O
in	O
the	O
SPDX	O
License	O
List	O
.	O
</s>
<s>
The	O
MIT	O
No	O
Attribution	O
License	O
,	O
a	O
variation	O
of	O
the	B-License
MIT	I-License
License	I-License
,	O
has	O
the	O
identifier	O
MIT-0	O
in	O
the	O
SPDX	O
License	O
List	O
.	O
</s>
<s>
The	O
SPDX	O
License	O
List	O
contains	O
extra	O
MIT	B-License
license	I-License
variations	O
.	O
</s>
<s>
The	O
name	O
"	O
MIT	B-License
License	I-License
"	O
is	O
potentially	O
ambiguous	O
.	O
</s>
<s>
The	O
Massachusetts	O
Institute	O
of	O
Technology	O
has	O
been	O
using	O
many	O
licenses	O
for	O
software	O
since	O
its	O
creation	O
;	O
for	O
example	O
,	O
MIT	O
offers	O
four	O
licensing	O
options	O
for	O
the	O
FFTW	B-Application
C	O
source	O
code	O
library	O
,	O
one	O
of	O
which	O
is	O
the	O
GPL	B-License
v2.0	I-License
and	O
the	O
other	O
three	O
of	O
which	O
are	O
not	O
open-source	B-Application
.	O
</s>
<s>
The	O
term	O
"	O
MIT	B-License
License	I-License
"	O
has	O
also	O
been	O
used	O
to	O
refer	O
to	O
the	O
Expat	B-License
License	I-License
(	O
used	O
for	O
the	O
XML	O
parsing	O
library	O
Expat	B-Language
)	O
and	O
to	O
the	O
X11	B-License
License	I-License
(	O
also	O
called	O
"	O
MIT/X	B-License
Consortium	I-License
License	I-License
"	O
;	O
used	O
for	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
by	O
the	O
MIT	B-License
X	I-License
Consortium	O
)	O
.	O
</s>
<s>
Furthermore	O
,	O
the	O
"	O
MIT	B-License
License	I-License
"	O
as	O
published	O
by	O
the	O
Open	O
Source	O
Initiative	O
is	O
the	O
same	O
as	O
the	O
Expat	B-License
License	I-License
.	O
</s>
<s>
Due	O
to	O
this	O
differing	O
use	O
of	O
terms	O
,	O
some	O
prefer	O
to	O
avoid	O
the	O
name	O
"	O
MIT	B-License
License	I-License
"	O
.	O
</s>
<s>
The	B-Operating_System
Free	I-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
argues	O
that	O
the	O
term	O
is	O
misleading	O
and	O
ambiguous	O
,	O
and	O
recommends	O
against	O
its	O
use	O
.	O
</s>
<s>
The	O
X	B-Operating_System
Consortium	O
was	O
dissolved	O
late	O
in	O
1996	O
,	O
and	O
its	O
assets	O
transferred	O
to	O
The	B-Application
Open	I-Application
Group	I-Application
,	O
which	O
released	O
X11R6	B-Operating_System
initially	O
under	O
the	O
same	O
license	O
.	O
</s>
<s>
The	O
X11	B-License
License	I-License
and	O
the	O
X11R6	B-Operating_System
"	O
MIT	B-License
License	I-License
"	O
chosen	O
for	O
ncurses	B-Language
by	O
the	B-Operating_System
Free	I-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
both	O
include	O
the	O
following	O
clause	O
,	O
absent	O
in	O
the	O
Expat	B-License
License	I-License
:	O
</s>
<s>
As	O
of	O
2020	O
,	O
the	O
successor	O
to	O
the	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
is	O
the	O
X.Org	B-Operating_System
Server	I-Operating_System
,	O
which	O
is	O
licensed	O
under	O
what	O
is	O
effectively	O
the	O
common	O
MIT	B-License
license	I-License
,	O
according	O
to	O
the	O
X.org	O
licensing	O
page	O
:	O
</s>
<s>
The	O
X.Org	O
Foundation	O
has	O
chosen	O
the	O
following	O
format	O
of	O
the	B-License
MIT	I-License
License	I-License
as	O
the	O
preferred	O
format	O
for	O
code	O
included	O
in	O
the	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
distribution	O
.	O
</s>
<s>
The	O
license-management	O
features	O
at	O
popular	O
source	O
code	O
repository	O
GitHub	B-Application
,	O
as	O
well	O
as	O
its	O
"	O
Choose	O
a	O
License	O
"	O
service	O
,	O
do	O
not	O
differentiate	O
between	O
MIT/Expat	B-License
license	I-License
variants	O
.	O
</s>
<s>
The	O
text	O
of	O
the	O
Expat	B-Language
variant	O
is	O
presented	O
as	O
simply	O
the	O
"	O
MIT	B-License
License	I-License
"	O
(	O
represented	O
by	O
the	O
metadata	O
tag	O
mit	O
)	O
.	O
</s>
<s>
The	O
original	O
BSD	B-Operating_System
license	I-Operating_System
also	O
includes	O
a	O
clause	O
requiring	O
all	O
advertising	O
of	O
the	O
software	O
to	O
display	O
a	O
notice	O
crediting	O
its	O
authors	O
.	O
</s>
<s>
This	O
"	O
advertising	O
clause	O
"	O
(	O
since	O
disavowed	O
by	O
UC	O
Berkeley	O
)	O
is	O
present	O
in	O
the	O
modified	O
MIT	B-License
License	I-License
used	O
by	O
XFree86	B-Device
.	O
</s>
<s>
The	O
University	B-License
of	I-License
Illinois/NCSA	I-License
Open	I-License
Source	I-License
License	I-License
combines	O
text	O
from	O
both	O
the	O
MIT	O
and	O
BSD	B-Operating_System
licenses	I-Operating_System
;	O
the	O
license	O
grant	O
and	O
disclaimer	O
are	O
taken	O
from	O
the	B-License
MIT	I-License
License	I-License
.	O
</s>
<s>
The	O
ISC	B-License
license	I-License
contains	O
similarities	O
to	O
both	O
the	O
MIT	O
and	O
simplified	O
BSD	B-Operating_System
licenses	I-Operating_System
,	O
the	O
biggest	O
difference	O
being	O
that	O
language	O
deemed	O
unnecessary	O
by	O
the	O
Berne	O
Convention	O
is	O
omitted	O
.	O
</s>
<s>
The	O
GNU	B-License
GPL	I-License
is	O
explicit	O
about	O
the	O
patent	O
grant	O
an	O
author	O
would	O
be	O
giving	O
when	O
the	O
code	O
(	O
or	O
derivative	O
work	O
)	O
is	O
distributed	O
,	O
the	B-License
MIT	I-License
license	I-License
does	O
not	O
discuss	O
patents	O
.	O
</s>
<s>
Moreover	O
,	O
the	O
GPL	B-License
license	I-License
impacts	O
derivative	O
works	O
,	O
but	O
the	B-License
MIT	I-License
license	I-License
does	O
not	O
.	O
</s>
<s>
Like	O
the	O
BSD	B-Operating_System
license	I-Operating_System
,	O
the	B-License
MIT	I-License
license	I-License
does	O
not	O
include	O
an	O
express	O
patent	O
license	O
although	O
some	O
commentators	O
state	O
that	O
the	O
grant	O
of	O
rights	O
covers	O
all	O
potential	O
restrictions	O
including	O
patents	O
.	O
</s>
<s>
Both	O
the	O
BSD	O
and	O
the	B-License
MIT	I-License
licenses	I-License
were	O
drafted	O
before	O
the	O
patentability	O
of	O
software	O
was	O
generally	O
recognized	O
under	O
US	O
law	O
.	O
</s>
<s>
The	O
Apache	B-Application
License	I-Application
version	O
2.0	O
is	O
a	O
similarly	O
permissive	B-License
license	I-License
that	O
includes	O
an	O
explicit	O
contributor	O
's	O
patent	O
license	O
.	O
</s>
<s>
Of	O
specific	O
relevance	O
to	O
US	O
jurisdictions	O
,	O
the	B-License
MIT	I-License
license	I-License
uses	O
the	O
terms	O
"	O
sell	O
"	O
and	O
"	O
use	O
"	O
that	O
are	O
also	O
used	O
in	O
defining	O
the	O
rights	O
of	O
a	O
patent	O
holder	O
in	O
Title	O
35	O
of	O
the	O
United	O
States	O
Code	O
section	O
154	O
.	O
</s>
<s>
One	O
of	O
the	O
originators	O
of	O
the	B-License
MIT	I-License
license	I-License
,	O
computer	O
scientist	O
Jerry	O
Saltzer	O
,	O
has	O
published	O
his	O
recollections	O
of	O
its	O
early	O
development	O
,	O
along	O
with	O
documentary	O
evidence	O
.	O
</s>
<s>
,	O
according	O
to	O
WhiteSource	O
Software	O
the	B-License
MIT	I-License
license	I-License
was	O
used	O
in	O
27%	O
of	O
four	O
million	O
open	O
source	O
packages	O
.	O
</s>
<s>
,	O
according	O
to	O
Black	O
Duck	O
Software	O
and	O
a	O
2015	O
blog	O
from	O
GitHub	B-Application
,	O
the	B-License
MIT	I-License
license	I-License
was	O
the	O
most	O
popular	O
open-source	B-Application
license	O
,	O
with	O
the	O
GNU	O
GPLv2	O
coming	O
second	O
in	O
their	O
sample	O
of	O
repositories	O
.	O
</s>
