<s>
The	O
Mozilla	B-License
Public	I-License
License	I-License
(	O
MPL	O
)	O
is	O
a	O
free	B-License
and	I-License
open-source	I-License
weak	O
copyleft	O
license	O
for	O
most	O
Mozilla	B-Operating_System
Foundation	I-Operating_System
software	O
such	O
as	O
Firefox	B-Application
and	O
Thunderbird	B-Application
.	O
</s>
<s>
The	O
MPL	B-License
license	I-License
is	O
developed	O
and	O
maintained	O
by	O
Mozilla	O
,	O
which	O
seeks	O
to	O
balance	O
the	O
concerns	O
of	O
both	O
open-source	O
and	O
proprietary	B-Application
developers	O
;	O
it	O
is	O
distinguished	O
from	O
others	O
as	O
a	O
middle	O
ground	O
between	O
the	O
permissive	B-License
software	I-License
BSD-style	B-Operating_System
licenses	I-Operating_System
and	O
the	O
General	B-License
Public	I-License
License	I-License
.	O
</s>
<s>
So	O
under	O
the	O
terms	O
of	O
the	O
MPL	O
,	O
it	O
allows	O
the	O
integration	O
of	O
MPL-licensed	O
code	O
into	O
proprietary	B-Application
codebases	O
,	O
but	O
only	O
on	O
condition	O
those	O
components	O
remain	O
accessible	O
.	O
</s>
<s>
MPL	O
has	O
been	O
used	O
by	O
others	O
,	O
such	O
as	O
Adobe	O
to	O
license	O
their	O
Flex	B-Operating_System
product	O
line	O
,	O
and	O
The	B-Operating_System
Document	I-Operating_System
Foundation	I-Operating_System
to	O
license	O
LibreOffice	B-Application
4.0	I-Application
(	O
also	O
on	O
LGPL	B-Application
3+	O
)	O
.	O
</s>
<s>
Version	O
1.1	O
was	O
adapted	O
by	O
several	O
projects	O
to	O
form	O
derivative	O
licenses	O
like	O
Sun	O
Microsystems	O
 '	O
Common	B-Application
Development	I-Application
and	I-Application
Distribution	I-Application
License	I-Application
.	O
</s>
<s>
A	O
patent	O
retaliation	O
clause	O
,	O
similar	O
to	O
that	O
of	O
the	O
Apache	B-Application
License	I-Application
,	O
is	O
included	O
to	O
protect	O
an	O
auxiliary	O
distributor	O
's	O
further	O
recipients	O
against	O
patent	O
trolling	O
.	O
</s>
<s>
Covered	O
source	O
code	O
files	B-Operating_System
must	O
remain	O
under	O
the	O
MPL	O
,	O
and	O
distributors	O
"	O
may	O
not	O
attempt	O
to	O
alter	O
or	O
restrict	O
recipients	O
 '	O
rights	O
"	O
to	O
it	O
.	O
</s>
<s>
The	O
MPL	O
treats	O
the	O
source	O
code	O
file	O
as	O
the	O
boundary	O
between	O
MPL-licensed	O
and	O
proprietary	B-Application
parts	O
,	O
meaning	O
that	O
all	O
or	O
none	O
of	O
the	O
code	O
in	O
a	O
given	O
source	O
file	O
falls	O
under	O
the	O
MPL	O
.	O
</s>
<s>
An	O
executable	O
consisting	O
solely	O
of	O
MPL-covered	O
files	B-Operating_System
may	O
be	O
sublicensed	O
,	O
but	O
the	O
licensee	O
must	O
ensure	O
access	O
to	O
or	O
provide	O
all	O
the	O
source	O
code	O
within	O
it	O
.	O
</s>
<s>
Recipients	O
can	O
combine	O
licensed	O
source	O
code	O
with	O
other	O
files	B-Operating_System
under	O
a	O
different	O
,	O
even	O
proprietary	B-Application
license	I-Application
,	O
thereby	O
forming	O
a	O
"	O
larger	O
work	O
"	O
which	O
can	O
be	O
distributed	O
under	O
any	O
terms	O
,	O
but	O
again	O
the	O
MPL-covered	O
source	O
files	B-Operating_System
must	O
be	O
made	O
freely	O
available	O
.	O
</s>
<s>
This	O
makes	O
the	O
MPL	O
a	O
compromise	O
between	O
the	O
MIT	B-License
or	O
BSD	B-Operating_System
licenses	I-Operating_System
,	O
which	O
permit	O
all	O
derived	O
works	O
to	O
be	O
relicensed	O
as	O
proprietary	B-Application
,	O
and	O
the	O
GPL	B-License
,	O
which	O
requires	O
the	O
derived	O
work	O
as	O
a	O
whole	O
to	O
be	O
licensed	O
under	O
the	O
GPL	B-License
.	O
</s>
<s>
By	O
allowing	O
proprietary	B-Application
modules	O
in	O
derived	O
projects	O
while	O
requiring	O
core	O
files	B-Operating_System
to	O
remain	O
open	O
source	O
,	O
the	O
MPL	O
is	O
designed	O
to	O
motivate	O
both	O
businesses	O
and	O
the	O
open-source	O
community	O
to	O
help	O
develop	O
core	O
software	O
.	O
</s>
<s>
The	O
one	O
exception	O
to	O
covered	O
source	O
files	B-Operating_System
remaining	O
under	O
the	O
MPL	O
occurs	O
when	O
code	O
under	O
version	O
2.0	O
or	O
later	O
is	O
combined	O
with	O
separate	O
code	O
files	B-Operating_System
under	O
the	O
GNU	B-License
GPL	I-License
,	O
GNU	O
Lesser	B-Application
GPL	I-Application
(	O
LGPL	B-Application
)	O
,	O
or	O
Affero	B-Application
GPL	I-Application
(	O
AGPL	O
)	O
.	O
</s>
<s>
In	O
this	O
case	O
,	O
the	O
program	O
as	O
a	O
whole	O
will	O
be	O
under	O
the	O
chosen	O
GNU	O
license	O
,	O
but	O
the	O
MPL-covered	O
files	B-Operating_System
will	O
be	O
dual-licensed	B-License
,	O
so	O
that	O
recipients	O
can	O
choose	O
to	O
distribute	O
them	O
under	O
that	O
GNU	O
License	O
or	O
the	O
MPL	O
.	O
</s>
<s>
The	O
initial	O
author	O
of	O
MPL	O
code	O
may	O
choose	O
to	O
opt	O
out	O
of	O
this	O
GPL	B-License
compatibility	O
by	O
adding	O
a	O
notice	O
to	O
its	O
source	O
files	B-Operating_System
.	O
</s>
<s>
If	O
code	O
under	O
version	O
1.0	O
or	O
1.1	O
is	O
upgraded	O
to	O
version	O
2.0	O
by	O
this	O
mechanism	O
,	O
the	O
1.x-covered	O
code	O
must	O
be	O
marked	O
with	O
the	O
aforementioned	O
GPL-incompatible	O
notice	O
.	O
</s>
<s>
The	O
MPL	O
can	O
be	O
modified	O
to	O
form	O
a	O
new	O
license	O
,	O
provided	O
that	O
said	O
license	O
does	O
not	O
refer	O
to	O
Mozilla	O
or	O
Netscape	B-Protocol
.	O
</s>
<s>
Version	O
1.0	O
of	O
the	O
MPL	O
was	O
written	O
by	O
Mitchell	O
Baker	O
in	O
1998	O
while	O
working	O
as	O
a	O
lawyer	O
at	O
Netscape	B-Protocol
Communications	O
Corporation	O
.	O
</s>
<s>
Netscape	B-Protocol
was	O
hoping	O
that	O
an	O
open-source	O
strategy	O
for	O
developing	O
its	O
own	O
Netscape	B-Protocol
web	I-Protocol
browser	I-Protocol
would	O
allow	O
it	O
to	O
compete	O
better	O
with	O
Microsoft	O
's	O
browser	O
,	O
Internet	B-Application
Explorer	I-Application
.	O
</s>
<s>
To	O
cover	O
the	O
browser	O
's	O
code	O
,	O
the	O
company	O
drafted	O
a	O
license	O
known	O
as	O
the	O
Netscape	B-Application
Public	I-Application
License	I-Application
(	O
NPL	O
)	O
,	O
which	O
included	O
a	O
clause	O
allowing	O
even	O
openly	O
developed	O
code	O
to	O
be	O
theoretically	O
relicensed	O
as	O
proprietary	B-Application
.	O
</s>
<s>
It	O
was	O
called	O
the	O
Mozilla	B-License
Public	I-License
License	I-License
after	O
Netscape	B-Protocol
's	O
project	O
name	O
for	O
the	O
new	O
open-source	O
codebase	O
,	O
and	O
,	O
although	O
it	O
was	O
originally	O
only	O
intended	O
for	O
software	O
that	O
supplemented	O
core	O
modules	O
covered	O
by	O
the	O
NPL	O
,	O
it	O
would	O
become	O
much	O
more	O
popular	O
than	O
the	O
NPL	O
and	O
eventually	O
earn	O
approval	O
from	O
the	O
Open	O
Source	O
Initiative	O
.	O
</s>
<s>
Less	O
than	O
a	O
year	O
later	O
,	O
Baker	O
and	O
the	O
Mozilla	B-Operating_System
Organization	I-Operating_System
would	O
make	O
some	O
changes	O
to	O
the	O
MPL	O
,	O
resulting	O
in	O
version	O
1.1	O
,	O
a	O
minor	O
update	O
.	O
</s>
<s>
The	O
primary	O
goals	O
were	O
to	O
clarify	O
terms	O
regarding	O
patents	O
and	O
allow	O
for	O
multiple	B-License
licensing	I-License
.	O
</s>
<s>
This	O
last	O
feature	O
was	O
meant	O
to	O
encourage	O
cooperation	O
with	O
developers	O
that	O
preferred	O
stricter	O
licenses	O
like	O
the	O
GPL	B-License
.	O
</s>
<s>
Not	O
only	O
would	O
many	O
projects	O
derive	O
their	O
own	O
licenses	O
from	O
this	O
version	O
,	O
but	O
its	O
structure	O
,	O
legal	O
precision	O
,	O
and	O
explicit	O
terms	O
for	O
patent	O
rights	O
would	O
strongly	O
influence	O
later	O
revisions	O
of	O
popular	O
licenses	O
like	O
the	O
GPL	B-License
(	O
version	O
3	O
)	O
.	O
</s>
<s>
Both	O
versions	O
1.0	O
and	O
1.1	O
are	O
incompatible	O
with	O
the	O
GPL	B-License
,	O
which	O
led	O
the	O
Free	O
Software	O
Foundation	O
to	O
discourage	O
using	O
version	O
1.1	O
.	O
</s>
<s>
For	O
these	O
reasons	O
,	O
earlier	O
versions	O
of	O
Firefox	B-Application
were	O
released	O
under	O
multiple	O
licenses	O
:	O
the	O
MPL	B-License
1.1	I-License
,	O
GPL	B-License
2.0	O
,	O
and	O
LGPL	B-Application
2.1	I-Application
.	O
</s>
<s>
Some	O
old	O
software	O
,	O
such	O
as	O
the	O
Mozilla	O
Application	O
Suite	O
,	O
is	O
still	O
under	O
the	O
three	B-License
licenses	I-License
.	O
</s>
<s>
Over	O
the	O
next	O
21	O
months	O
,	O
the	O
MPL	O
was	O
not	O
only	O
changed	O
to	O
make	O
the	O
license	O
clearer	O
and	O
easier	O
to	O
apply	O
,	O
but	O
also	O
to	O
achieve	O
compatibility	O
with	O
the	O
GPL	B-License
and	O
Apache	B-Application
licenses	I-Application
.	O
</s>
