<s>
The	O
Debian	B-License
Free	I-License
Software	I-License
Guidelines	I-License
(	O
DFSG	B-License
)	O
is	O
a	O
set	O
of	O
guidelines	O
that	O
the	O
Debian	O
Project	O
uses	O
to	O
determine	O
whether	O
a	O
software	O
license	O
is	O
a	O
free	B-License
software	I-License
license	I-License
,	O
which	O
in	O
turn	O
is	O
used	O
to	O
determine	O
whether	O
a	O
piece	O
of	O
software	O
can	O
be	O
included	O
in	O
Debian	O
.	O
</s>
<s>
The	O
DFSG	B-License
is	O
part	O
of	O
the	O
Debian	O
Social	O
Contract	O
.	O
</s>
<s>
The	O
GNU	B-License
GPL	I-License
,	O
BSD	B-Operating_System
,	O
and	O
Artistic	B-License
licenses	I-License
are	O
examples	O
of	O
licenses	O
considered	O
free	O
.	O
</s>
<s>
The	O
DFSG	B-License
was	O
first	O
published	O
together	O
with	O
the	O
first	O
version	O
of	O
the	O
Debian	O
Social	O
Contract	O
in	O
July	O
1997	O
.	O
</s>
<s>
Perens	O
was	O
copied	O
to	O
an	O
email	O
discussion	O
between	O
Ean	O
Schuessler	O
(	O
then	O
of	O
Debian	O
)	O
and	O
Donnie	O
Barnes	O
of	O
Red	O
Hat	O
,	O
in	O
which	O
Schuessler	O
accused	O
Red	O
Hat	O
of	O
never	O
elucidating	O
its	O
social	O
contract	O
with	O
the	O
Linux	B-Application
community	I-Application
.	O
</s>
<s>
The	B-License
Open	I-License
Source	I-License
Definition	I-License
was	O
created	O
by	O
re-titling	O
the	O
exact	O
text	O
of	O
the	O
DFSG	B-License
soon	O
afterwards	O
.	O
</s>
<s>
DFSG	B-License
was	O
preceded	O
by	O
Free	B-Operating_System
Software	I-Operating_System
Foundation	I-Operating_System
's	O
Free	B-Application
Software	I-Application
Definition	I-Application
,	O
which	O
then	O
defined	O
three	O
freedoms	O
of	O
Free	B-Application
Software	I-Application
(	O
Freedom	B-Application
Zero	I-Application
was	O
added	O
later	O
)	O
,	O
but	O
this	O
text	O
was	O
not	O
used	O
in	O
the	O
creation	O
of	O
the	O
DFSG	B-License
.	O
</s>
<s>
Once	O
the	O
DFSG	B-License
became	O
the	B-License
Open	I-License
Source	I-License
Definition	I-License
,	O
Richard	O
Stallman	O
saw	O
the	O
need	O
to	O
differentiate	O
free	B-Application
software	I-Application
from	O
open	B-Application
source	I-Application
and	O
promoted	O
the	B-Application
Free	I-Application
Software	I-Application
Definition	I-Application
.	O
</s>
<s>
Published	O
versions	O
of	O
FSF	O
's	O
Free	B-Application
Software	I-Application
Definition	I-Application
existed	O
as	O
early	O
as	O
1986	O
,	O
having	O
been	O
published	O
in	O
the	O
first	O
edition	O
of	O
the	O
(	O
now	O
defunct	O
)	O
GNU	O
's	O
Bulletin	O
.	O
</s>
<s>
The	O
core	O
of	O
the	B-Application
Free	I-Application
Software	I-Application
Definition	I-Application
was	O
the	O
(	O
then	O
)	O
Three	O
Freedoms	O
,	O
which	O
preceded	O
the	O
drafting	O
and	O
promulgation	O
of	O
the	O
DFSG	B-License
,	O
were	O
unknown	O
to	O
its	O
authors	O
.	O
</s>
<s>
Nevertheless	O
,	O
there	O
were	O
changes	O
made	O
to	O
the	O
Social	O
Contract	O
which	O
were	O
considered	O
to	O
affect	O
the	O
parts	O
of	O
the	O
distribution	O
covered	O
by	O
the	O
DFSG	B-License
.	O
</s>
<s>
However	O
,	O
the	O
change	O
of	O
the	O
sentence	O
"	O
We	O
promise	O
to	O
keep	O
the	O
Debian	O
GNU/Linux	O
Distribution	O
entirely	O
free	B-Application
software	I-Application
"	O
into	O
"	O
We	O
promise	O
that	O
the	O
Debian	O
system	O
and	O
all	O
its	O
components	O
will	O
be	O
free	O
"	O
resulted	O
in	O
the	O
release	O
manager	O
,	O
Anthony	O
Towns	O
,	O
making	O
a	O
practical	O
change	O
:	O
</s>
<s>
Most	O
discussions	O
about	O
the	O
DFSG	B-License
happen	O
on	O
the	O
debian-legal	O
mailing	O
list	O
.	O
</s>
<s>
The	O
DFSG	B-License
is	O
focused	O
on	O
software	O
,	O
but	O
the	O
word	O
itself	O
is	O
unclear	O
—	O
some	O
apply	O
it	O
to	O
everything	O
that	O
can	O
be	O
expressed	O
as	O
a	O
stream	O
of	O
bits	O
,	O
while	O
a	O
minority	O
considers	O
it	O
to	O
refer	O
to	O
just	O
computer	O
programs	O
.	O
</s>
<s>
Also	O
,	O
the	O
existence	O
of	O
PostScript	B-Language
,	O
executable	O
scripts	O
,	O
sourced	O
documents	O
,	O
etc.	O
,	O
greatly	O
muddies	O
the	O
second	O
definition	O
.	O
</s>
<s>
The	O
non-program	O
content	O
of	O
Debian	O
began	O
to	O
comply	O
with	O
the	O
DFSG	B-License
more	O
strictly	O
in	O
Debian	O
4.0	O
(	O
released	O
in	O
April	O
2007	O
)	O
and	O
subsequent	O
releases	O
.	O
</s>
<s>
Much	O
documentation	O
written	O
by	O
the	B-Application
GNU	I-Application
Project	I-Application
,	O
the	O
Linux	O
Documentation	O
Project	O
and	O
others	O
licensed	O
under	O
the	O
GNU	B-Application
Free	I-Application
Documentation	I-Application
License	I-Application
contain	O
invariant	O
sections	O
,	O
which	O
do	O
not	O
comply	O
with	O
the	O
DFSG	B-License
.	O
</s>
<s>
Due	O
to	O
the	O
GFDL	B-Application
invariant	O
sections	O
,	O
content	O
under	O
this	O
license	O
must	O
be	O
separately	O
contained	O
in	O
an	O
additional	O
"	O
non-free	O
"	O
repository	O
which	O
is	O
not	O
officially	O
considered	O
part	O
of	O
Debian	O
.	O
</s>
<s>
It	O
can	O
be	O
sometimes	O
hard	O
to	O
define	O
what	O
constitutes	O
the	O
"	O
source	O
"	O
for	O
multimedia	O
files	O
,	O
such	O
as	O
whether	O
an	O
uncompressed	O
image	O
file	O
is	O
the	O
source	O
of	O
a	O
compressed	O
image	O
and	O
whether	O
the	O
3D	O
model	O
before	O
ray	B-Algorithm
tracing	I-Algorithm
is	O
the	O
source	O
for	O
its	O
resulting	O
image	O
.	O
</s>
<s>
The	O
debian-legal	O
mailing	O
list	O
subscribers	O
have	O
created	O
some	O
tests	O
to	O
check	O
whether	O
a	O
license	O
violates	O
the	O
DFSG	B-License
.	O
</s>
<s>
The	O
common	O
tests	O
(	O
as	O
described	O
in	O
the	O
draft	O
DFSG	B-License
FAQ	O
)	O
are	O
the	O
following	O
:	O
</s>
<s>
"	O
The	O
Desert	B-License
Island	I-License
test	I-License
"	O
.	O
</s>
<s>
"	O
The	O
Dissident	B-License
test	I-License
"	O
.	O
</s>
<s>
"	O
The	O
Tentacles	B-License
of	I-License
Evil	I-License
test	I-License
"	O
.	O
</s>
<s>
The	O
same	O
can	O
happen	O
to	O
a	O
corporation	O
bought	O
out	O
by	O
a	O
larger	O
corporation	O
bent	O
on	O
destroying	O
free	B-Application
software	I-Application
in	O
order	O
to	O
maintain	O
its	O
monopoly	O
and	O
extend	O
its	O
evil	O
empire	O
.	O
</s>
