<s>
The	O
LaTeX	B-Application
Project	I-Application
Public	I-Application
License	I-Application
(	O
LPPL	B-Application
)	O
is	O
a	O
software	B-License
license	I-License
originally	O
written	O
for	O
the	O
LaTeX	B-Application
system	O
.	O
</s>
<s>
Software	O
distributed	O
under	O
the	O
terms	O
of	O
the	O
LPPL	B-Application
can	O
be	O
regarded	O
as	O
free	B-Application
software	I-Application
;	O
however	O
,	O
it	O
is	O
not	O
copylefted	B-License
.	O
</s>
<s>
Besides	O
the	O
LaTeX	B-Application
base	O
system	O
,	O
the	O
LPPL	B-Application
is	O
also	O
used	O
for	O
most	O
third-party	O
LaTeX	B-Application
packages	O
.	O
</s>
<s>
Software	O
projects	O
other	O
than	O
LaTeX	B-Application
rarely	O
use	O
it	O
.	O
</s>
<s>
The	O
LPPL	B-Application
grew	O
from	O
Donald	O
Knuth	O
's	O
original	O
license	O
for	O
TeX	O
,	O
which	O
states	O
that	O
the	O
source	O
code	O
for	O
TeX	O
may	O
be	O
used	O
for	O
any	O
purpose	O
but	O
a	O
system	O
built	O
with	O
it	O
can	O
only	O
be	O
called	O
'	O
TeX	O
 '	O
if	O
it	O
strictly	O
conforms	O
to	O
his	O
canonical	O
program	O
.	O
</s>
<s>
Quoting	O
Frank	O
Mittelbach	O
,	O
the	O
main	O
author	O
of	O
the	O
license	O
:	O
"	O
LPPL	B-Application
attempts	O
to	O
preserve	O
the	O
fact	O
that	O
something	O
like	O
LaTeX	B-Application
is	O
a	O
language	O
which	O
is	O
used	O
for	O
communication	O
,	O
that	O
is	O
if	O
you	O
write	O
a	O
LaTeX	B-Application
document	O
you	O
expect	O
to	O
be	O
able	O
to	O
send	O
it	O
to	O
me	O
and	O
to	O
work	O
at	O
my	O
end	O
like	O
it	O
does	O
at	O
yours	O
"	O
.	O
</s>
<s>
The	O
most	O
unusual	O
part	O
of	O
the	O
LPPL	B-Application
and	O
equally	O
the	O
most	O
controversial	O
used	O
to	O
be	O
the	O
'	O
filename	O
clause	O
 '	O
:	O
You	O
must	O
not	O
distribute	O
the	O
modified	O
file	O
with	O
the	O
filename	O
of	O
the	O
original	O
file	O
.	O
</s>
<s>
This	O
feature	O
made	O
some	O
people	O
deny	O
that	O
the	O
LPPL	B-Application
is	O
a	O
free	B-License
software	I-License
license	I-License
.	O
</s>
<s>
In	O
particular	O
the	O
Debian	O
community	O
considered	O
in	O
2003	O
excluding	O
LaTeX	B-Application
from	O
its	O
core	O
distribution	O
because	O
of	O
this	O
.	O
</s>
<s>
However	O
,	O
version	O
1.3	O
of	O
the	O
LPPL	B-Application
has	O
weakened	O
this	O
restriction	O
.	O
</s>
<s>
The	O
LaTeX	B-Application
project	O
holds	O
the	O
copyright	O
for	O
the	O
text	O
of	O
the	O
LPPL	B-Application
,	O
but	O
it	O
does	O
not	O
necessarily	O
hold	O
the	O
copyright	O
for	O
a	O
work	O
released	O
under	O
the	O
LPPL	B-Application
.	O
</s>
<s>
Unlike	O
the	O
works	O
released	O
under	O
the	O
LPPL	B-Application
,	O
the	O
LPPL	B-Application
itself	O
is	O
not	O
freely	O
modifiable	O
.	O
</s>
<s>
While	O
copying	O
and	O
distribution	O
is	O
allowed	O
,	O
changing	O
the	O
text	O
of	O
the	O
LPPL	B-Application
is	O
not	O
.	O
</s>
<s>
However	O
,	O
it	O
may	O
be	O
used	O
as	O
a	O
model	O
for	O
other	O
licenses	O
provided	O
they	O
do	O
not	O
reference	O
the	O
LPPL	B-Application
.	O
</s>
