<s>
In	O
the	O
macOS	B-Application
,	O
iOS	B-Operating_System
,	O
NeXTSTEP	B-Application
,	O
and	O
GNUstep	B-Application
programming	O
frameworks	B-Architecture
,	O
property	O
list	O
files	O
are	O
files	O
that	O
store	O
serialized	B-Application
objects	I-Application
.	O
</s>
<s>
They	O
are	O
also	O
used	O
to	O
store	O
information	O
about	O
bundles	B-Application
and	O
applications	O
,	O
a	O
task	O
served	O
by	O
the	O
resource	B-Operating_System
fork	I-Operating_System
in	O
the	O
old	O
Mac	B-Application
OS	I-Application
.	O
</s>
<s>
Property	O
lists	O
are	O
also	O
used	O
for	O
localization	B-General_Concept
strings	O
for	O
development	O
.	O
</s>
<s>
The	O
former	O
is	O
a	O
"	O
reduced	O
"	O
old-style	O
plist	O
containing	O
only	O
one	O
dictionary	B-Application
without	O
the	O
braces	O
(	O
see	O
)	O
,	O
while	O
the	O
latter	O
is	O
a	O
fully-fledged	O
plist	O
.	O
</s>
<s>
Xcode	B-Operating_System
also	O
uses	O
a	O
.pbxproj	O
extension	O
for	O
old-style	O
plists	O
used	O
as	O
project	O
files	O
.	O
</s>
<s>
Since	O
the	O
data	O
represented	O
by	O
property	O
lists	O
is	O
somewhat	O
abstract	B-Application
,	O
the	O
underlying	O
file	O
format	O
can	O
be	O
implemented	O
many	O
ways	O
.	O
</s>
<s>
Namely	O
,	O
NeXTSTEP	B-Application
used	O
one	O
format	O
to	O
represent	O
a	O
property	O
list	O
,	O
and	O
the	O
subsequent	O
GNUstep	B-Application
and	O
macOS	B-Application
frameworks	B-Architecture
introduced	O
differing	O
formats	O
.	O
</s>
<s>
Under	O
NeXTSTEP	B-Application
,	O
property	O
lists	O
were	O
designed	O
to	O
be	O
human-readable	B-General_Concept
and	O
edited	O
by	O
hand	O
,	O
serialized	B-Application
to	O
ASCII	B-Protocol
in	O
a	O
syntax	O
somewhat	O
like	O
a	O
programming	O
language	O
.	O
</s>
<s>
This	O
same	O
format	O
was	O
used	O
by	O
OPENSTEP	B-Operating_System
.	O
</s>
<s>
Binary	O
data	O
are	O
represented	O
as	O
:	O
< [hexadecimal codes in ASCII] >	O
.	O
</s>
<s>
Dictionaries	B-Application
are	O
represented	O
as	O
:	O
.	O
</s>
<s>
As	O
a	O
result	O
,	O
these	O
values	O
would	O
have	O
to	O
be	O
converted	O
to	O
string	O
,	O
and	O
"	O
fuzzily	O
"	O
recovered	O
by	O
the	O
application	B-Application
.	O
</s>
<s>
The	O
defaults	B-Application
utility	O
,	O
introduced	O
in	O
OPENSTEP	B-Operating_System
(	O
1996	O
)	O
,	O
can	O
be	O
used	O
to	O
manipulate	O
plist	O
files	O
used	O
for	O
storage	O
of	O
preferences	O
(	O
known	O
as	O
defaults	B-Application
in	O
NeXTSTEP	B-Application
,	O
hence	O
the	O
name	O
)	O
on	O
the	O
command	O
line	O
via	O
their	O
preferences	O
domain	O
,	O
and	O
this	O
utility	O
can	O
be	O
used	O
to	O
edit	O
arbitrary	O
plist	O
files	O
.	O
</s>
<s>
GNUstep	B-Application
adopts	O
the	O
NeXTSTEP	B-Application
format	O
,	O
with	O
additions	O
for	O
representing	O
NSValue	O
and	O
NSDate	O
data	O
types	O
.	O
</s>
<s>
Binary	O
data	O
can	O
also	O
use	O
the	O
more	O
efficient	O
base64	B-Protocol
format	O
as	O
.	O
</s>
<s>
All	O
in	O
all	O
,	O
brings	O
the	O
expressiveness	O
and	O
compactness	O
of	O
the	O
human-readable	B-General_Concept
textual	O
format	O
on	O
par	O
with	O
Apple	O
's	O
XML	B-Protocol
format	O
.	O
</s>
<s>
GNUstep	B-Application
also	O
has	O
its	O
own	O
binary	O
format	O
,	O
,	O
implemented	O
in	O
.	O
</s>
<s>
Two	O
relative	O
independent	O
plist	O
handlers	O
are	O
found	O
in	O
GNUstep	B-Application
:	O
the	O
in	O
(	O
CoreFoundation	B-Operating_System
)	O
,	O
and	O
the	O
in	O
(	O
Foundation	O
Kit	O
)	O
.	O
</s>
<s>
Both	O
support	O
the	O
binary	O
and	O
XML	B-Protocol
forms	O
used	O
by	O
macOS	B-Application
to	O
some	O
degree	O
,	O
but	O
the	O
latter	O
is	O
a	O
lot	O
more	O
complete	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
two	O
GNUstep-specific	O
formats	O
are	O
only	O
handled	O
in	O
the	O
latter	O
.	O
</s>
<s>
GNUstep	B-Application
provides	O
a	O
set	O
of	O
plist	O
command-line	O
tools	O
based	O
on	O
,	O
including	O
a	O
version	O
of	O
and	O
.	O
</s>
<s>
While	O
macOS	B-Application
can	O
also	O
read	O
the	O
NeXTSTEP	B-Application
format	O
,	O
Apple	O
sets	O
it	O
aside	O
in	O
favor	O
of	O
two	O
new	O
formats	O
of	O
its	O
own	O
,	O
one	O
XML-based	O
and	O
the	O
other	O
binary	O
.	O
</s>
<s>
Apple	O
also	O
has	O
a	O
partially-compatible	O
JSON	B-General_Concept
format	O
(	O
)	O
.	O
</s>
<s>
In	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
10.0	I-Operating_System
,	O
the	O
NeXTSTEP	B-Application
format	O
was	O
deprecated	B-General_Concept
,	O
and	O
a	O
new	O
XML	B-Protocol
format	O
was	O
introduced	O
,	O
with	O
a	O
public	O
DTD	O
defined	O
by	O
Apple	O
.	O
</s>
<s>
The	O
XML	B-Protocol
format	O
supports	O
non-ASCII	O
characters	O
and	O
storing	O
NSValue	O
objects	O
(	O
which	O
,	O
unlike	O
GNUstep	B-Application
's	O
ASCII	B-Protocol
property	O
list	O
format	O
,	O
Apple	O
's	O
ASCII	B-Protocol
property	O
list	O
format	O
does	O
not	O
support	O
)	O
.	O
</s>
<s>
Since	O
XML	B-Protocol
files	O
,	O
however	O
,	O
are	O
not	O
the	O
most	O
space-efficient	O
means	O
of	O
storage	O
,	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
10.2	I-Operating_System
introduced	O
a	O
new	O
format	O
where	O
property	O
list	O
files	O
are	O
stored	O
as	O
binary	O
files	O
.	O
</s>
<s>
Starting	O
with	O
Mac	B-Application
OS	I-Application
X	I-Application
10.4	I-Application
,	O
this	O
is	O
the	O
default	O
format	O
for	O
preference	O
files	O
.	O
</s>
<s>
In	O
Mac	B-Application
OS	I-Application
X	I-Application
10.7	I-Application
,	O
support	O
for	O
reading	O
and	O
writing	O
files	O
in	O
JSON	B-General_Concept
format	O
was	O
introduced	O
.	O
</s>
<s>
JSON	B-General_Concept
and	O
property	O
lists	O
are	O
not	O
fully	O
compatible	O
with	O
each	O
other	O
,	O
though	O
.	O
</s>
<s>
For	O
example	O
,	O
property	O
lists	O
have	O
native	O
date	O
and	O
data	O
types	O
,	O
which	O
the	O
JSON	B-General_Concept
format	O
does	O
not	O
support	O
.	O
</s>
<s>
Conversely	O
,	O
JSON	B-General_Concept
permits	O
null	O
values	O
while	O
property	O
lists	O
do	O
not	O
support	O
explicit	O
nulls	O
.	O
</s>
<s>
The	O
old	O
tool	O
from	O
NeXTSTEP	B-Application
remains	O
available	O
.	O
</s>
<s>
The	O
utility	O
(	O
introduced	O
in	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
10.2	I-Operating_System
)	O
can	O
be	O
used	O
to	O
check	O
the	O
syntax	O
of	O
property	O
lists	O
,	O
or	O
convert	O
a	O
property	O
list	O
file	O
from	O
one	O
format	O
to	O
another	O
.	O
</s>
<s>
(	O
The	O
Cocoa	O
from	O
before	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
10.2	I-Operating_System
emits	O
old-styled	O
output	O
.	O
)	O
</s>
<s>
The	O
utility	O
is	O
introduced	O
in	O
Mac	B-Application
OS	I-Application
X	I-Application
v10.5	I-Application
.	O
</s>
<s>
Like	O
the	O
GNUstep	B-Application
version	O
,	O
it	O
appears	O
to	O
use	O
the	O
property	O
of	O
Foundation	O
types	O
found	O
in	O
plists	O
,	O
which	O
Apple	O
has	O
specified	O
to	O
produce	O
valid	O
old-style	O
plists	O
.	O
</s>
<s>
In	O
terms	O
of	O
the	O
internals	O
,	O
Apple	O
provides	O
an	O
open	O
source	O
parser	O
for	O
old	O
style	O
,	O
XML	B-Protocol
,	O
and	O
binary	O
formats	O
in	O
their	O
C	O
Core	B-Operating_System
Foundation	I-Operating_System
code	O
as	O
CFPropertyList	O
.	O
</s>
<s>
XML	B-Protocol
and	O
JSON	B-General_Concept
property	O
lists	O
are	O
hand-editable	O
in	O
any	O
text	O
editor	O
.	O
</s>
<s>
Additionally	O
,	O
Apple	O
provides	O
support	O
in	O
Xcode	B-Operating_System
for	O
editing	O
property	O
lists	O
in	O
a	O
hierarchical	O
viewer/editor	O
that	O
can	O
handle	O
plists	O
formatted	O
in	O
binary	O
or	O
XML	B-Protocol
,	O
but	O
not	O
JSON	B-General_Concept
.	O
</s>
<s>
As	O
of	O
Mac	B-Application
OS	I-Application
X	I-Application
10.4	I-Application
,	O
Apple	O
provides	O
an	O
AppleScript	B-Application
interface	O
for	O
reading	O
property	O
list	O
files	O
through	O
the	O
System	O
Events	O
application	B-Application
.	O
</s>
<s>
As	O
of	O
Mac	B-Application
OS	I-Application
X	I-Application
10.5	I-Application
,	O
Apple	O
provides	O
an	O
AppleScript	B-Application
interface	O
for	O
editing	O
,	O
creating	O
and	O
writing	O
property	O
list	O
files	O
as	O
well	O
.	O
</s>
<s>
For	O
the	O
XML	B-Protocol
format	O
,	O
the	O
tags	O
,	O
related	O
Foundation	O
classes	O
and	O
CoreFoundation	B-Operating_System
types	O
,	O
and	O
data	O
storage	O
formats	O
are	O
as	O
follows	O
:	O
</s>
<s>
No	O
data	O
(	O
tag	O
only	O
)	O
ISO	O
8601	O
formatted	O
string	O
Base64	B-Protocol
encoded	O
data	O
Can	O
contain	O
any	O
number	O
of	O
child	O
elements	O
.	O
</s>
<s>
The	O
Binary	O
file	O
format	O
is	O
documented	O
in	O
a	O
comment	O
block	O
in	O
the	O
Core	B-Operating_System
Foundation	I-Operating_System
C	O
code	O
source	O
file	O
(	O
)	O
for	O
Apple	O
's	O
open	O
sourced	O
implementation	O
of	O
binary	O
plists	O
in	O
its	O
Foundation	O
library	O
.	O
</s>
<s>
The	O
binary	O
file	O
can	O
store	O
some	O
information	O
that	O
cannot	O
be	O
captured	O
in	O
the	O
XML	B-Protocol
or	O
JSON	B-General_Concept
file	O
formats	O
.	O
</s>
<s>
The	O
array	O
,	O
set	O
and	O
dictionary	B-Application
binary	O
types	O
are	O
made	O
up	O
of	O
pointers	O
-	O
the	O
objref	O
and	O
keyref	O
entries	O
-	O
that	O
index	O
into	O
an	O
object	O
table	O
in	O
the	O
file	O
.	O
</s>
<s>
This	O
means	O
that	O
binary	O
plists	O
can	O
capture	O
the	O
fact	O
that	O
-	O
for	O
example	O
-	O
a	O
separate	O
array	O
and	O
dictionary	B-Application
serialized	B-Application
into	O
a	O
file	O
both	O
have	O
the	O
same	O
data	O
element	O
stored	O
in	O
them	O
.	O
</s>
<s>
This	O
cannot	O
be	O
captured	O
in	O
an	O
XML	B-Protocol
file	O
.	O
</s>
<s>
Converting	O
such	O
a	O
binary	O
file	O
will	O
result	O
in	O
a	O
copy	O
of	O
the	O
data	O
element	O
being	O
placed	O
into	O
the	O
XML	B-Protocol
file	O
.	O
</s>
<s>
Additionally	O
the	O
binary	O
file	O
has	O
a	O
UID	O
type	O
that	O
is	O
used	O
to	O
identify	O
data	O
items	O
when	O
serialized	B-Application
.	O
</s>
<s>
+Binary	O
plist	O
object	O
formats	O
(	O
as	O
of	O
CoreFoundation	B-Operating_System
1153	O
)	O
Foundation	O
classCoreFoundation	O
typeObject	O
typeMarker	O
byteEncoded	O
data	O
(	O
v	O
"	O
1	O
?	O
</s>
<s>
"	O
+	O
)	O
16	O
bytes	O
of	O
UUID	O
nothing	O
-	O
just	O
a	O
padding	O
#	O
of	O
bytes	O
is	O
2^nnnn	O
,	O
big-endian	O
bytes	O
(	O
1	O
,	O
2	O
,	O
4	O
,	O
or	O
8	O
)	O
#	O
of	O
bytes	O
is	O
2^nnnn	O
,	O
big-endian	O
bytes	O
(	O
4	O
or	O
8	O
)	O
8	O
byte	O
float	O
follows	O
,	O
big-endian	O
bytes	O
;	O
seconds	O
from	O
1/1/2001	O
(	O
Core	B-Application
Data	I-Application
epoch	O
)	O
nnnn	O
is	O
number	O
of	O
bytes	O
unless	O
1111	O
then	O
int	O
count	O
follows	O
,	O
followed	O
by	O
bytes	O
ASCII	B-Protocol
string	O
,	O
nnnn	O
is	O
#	O
of	O
chars	O
,	O
else	O
1111	O
then	O
int	O
count	O
,	O
then	O
bytes	O
Unicode	O
string	O
,	O
nnnn	O
is	O
#	O
of	O
chars	O
,	O
else	O
1111	O
then	O
int	O
count	O
,	O
then	O
big-endian	O
2-byte	O
uint16_t	O
(	O
v	O
"	O
1	O
?	O
</s>
<s>
The	O
OpenStep	B-Operating_System
specification	O
abstracts	O
the	O
operation	O
of	O
serializing	B-Application
any	O
under	O
the	O
protocol	O
.	O
</s>
<s>
Any	O
class	O
implementing	O
this	O
protocol	O
can	O
have	O
its	O
instances	O
serialized	B-Application
by	O
a	O
subclass	O
to	O
some	O
other	O
format	O
.	O
</s>
<s>
Two	O
main	O
coders	O
exist	O
for	O
the	O
purpose	O
of	O
serializing	B-Application
objects	O
to	O
plists	O
:	O
</s>
<s>
This	O
class	O
is	O
part	O
of	O
OpenStep	B-Operating_System
,	O
although	O
no	O
concrete	O
format	O
has	O
been	O
defined	O
.	O
</s>
<s>
In	O
practice	O
,	O
one	O
can	O
use	O
it	O
to	O
serialize	B-Application
an	O
object	O
to	O
a	O
file	O
(	O
skipping	O
the	O
plist	O
)	O
,	O
or	O
to	O
embed	O
the	O
data	O
in	O
a	O
plist	O
.	O
</s>
<s>
The	O
introduction	O
of	O
deprecates	B-General_Concept
its	O
use	O
.	O
</s>
<s>
,	O
introduced	O
in	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
10.2	I-Operating_System
,	O
transforms	O
the	O
object	O
into	O
an	O
.	O
</s>
<s>
Internally	O
,	O
it	O
somewhat	O
recapitulates	O
the	O
binary	O
plist	O
format	O
by	O
storing	O
an	O
object	O
table	O
array	O
called	O
in	O
the	O
dictionary	B-Application
.	O
</s>
<s>
Since	O
there	O
is	O
not	O
a	O
UID	O
data	O
type	O
in	O
XML	B-Protocol
,	O
the	O
integers	O
are	O
stored	O
in	O
a	O
dictionary	B-Application
under	O
the	O
key	O
"	O
CF$UID	O
"	O
.	O
</s>
<s>
Apple	O
publishes	O
an	O
open-source	O
in	O
Swift	O
Corelibs	O
Foundation	O
;	O
like	O
the	O
closed-source	O
Apple	O
Foundation	O
,	O
it	O
restricts	O
output	O
formats	O
to	O
binary	O
and	O
XML	B-Protocol
only	O
.	O
</s>
<s>
It	O
also	O
has	O
some	O
test	O
cases	O
showing	O
the	O
results	O
of	O
serialization	B-Application
.	O
</s>
<s>
GNUstep	B-Application
also	O
has	O
a	O
compatible	O
implementation	O
,	O
which	O
does	O
not	O
limit	O
output	O
formats	O
.	O
</s>
<s>
There	O
is	O
not	O
a	O
single	O
,	O
standardized	O
path	O
language	O
for	O
property	O
lists	O
like	O
XPath	B-Language
does	O
for	O
XML	B-Protocol
,	O
but	O
informal	O
conventions	O
used	O
by	O
various	O
programs	O
exist	O
.	O
</s>
<s>
Although	O
best	O
known	O
on	O
Apple	O
or	O
Darwin	O
systems	O
,	O
including	O
iOS	B-Operating_System
and	O
macOS	B-Application
,	O
plist	O
files	O
are	O
also	O
present	O
on	O
Windows	O
computers	O
when	O
Apple	O
software	O
,	O
such	O
as	O
iTunes	B-Operating_System
or	O
Safari	O
are	O
installed	O
.	O
</s>
<s>
Options	O
for	O
editing	O
PLIST	O
files	O
on	O
Windows	O
are	O
not	O
as	O
extensive	O
as	O
on	O
macOS	B-Application
.	O
</s>
<s>
If	O
the	O
file	O
is	O
in	O
the	O
XML	B-Protocol
or	O
JSON	B-General_Concept
format	O
with	O
care	O
a	O
text	O
editor	O
such	O
as	O
Notepad++	B-Language
can	O
be	O
used	O
.	O
</s>
<s>
Apple	O
ships	O
a	O
plutil.exe	O
within	O
its	O
"	O
Apple	O
Application	B-Application
Support	O
"	O
package	O
(	O
which	O
is	O
part	O
of	O
iTunes	B-Operating_System
)	O
,	O
and	O
it	O
is	O
identical	O
to	O
its	O
macOS	B-Application
counterpart	O
.	O
</s>
<s>
Introduced	O
in	O
2006	O
and	O
first	O
released	O
with	O
NetBSD	B-Device
#4	O
.0	O
(	O
2007	O
)	O
is	O
a	O
proplib	B-Application
library	O
,	O
which	O
can	O
be	O
used	O
for	O
serialising	O
data	O
between	O
the	O
kernel	O
and	O
userland	O
.	O
</s>
<s>
It	O
implements	O
part	O
of	O
the	O
XML	B-Protocol
plist	O
language	O
.	O
</s>
<s>
One	O
of	O
the	O
sample	O
users	O
of	O
proplib	B-Application
is	O
the	O
second	O
revision	O
of	O
the	O
sysmon	B-Device
envsys	I-Device
framework	O
for	O
system	B-Application
monitoring	I-Application
.	O
</s>
<s>
NetBSD	B-Device
's	O
proplib	B-Application
library	O
has	O
also	O
been	O
ported	O
to	O
DragonFly	O
in	O
2010	O
,	O
and	O
is	O
available	O
since	O
DragonFly	B-Application
BSD	I-Application
#2	O
.8	O
.	O
</s>
<s>
Facebook	B-Application
's	O
open-source	O
reimplementation	O
of	O
the	O
Xcode	B-Operating_System
build	O
tool	O
,	O
xcbuild	O
,	O
contains	O
a	O
plist	O
library	O
as	O
well	O
as	O
and	O
.	O
</s>
<s>
These	O
cross-platform	O
utilities	O
are	O
written	O
in	O
C++	B-Language
.	O
</s>
<s>
The	O
Python	B-Language
programming	I-Language
language	I-Language
has	O
a	O
builtin	O
module	O
to	O
read	O
and	O
write	O
plist	O
files	O
,	O
in	O
Apple	O
's	O
XML	B-Protocol
or	O
in	O
binary	O
(	O
since	O
Python	B-Language
3.4	O
)	O
.	O
</s>
<s>
Go	B-Application
has	O
a	O
package	O
that	O
supports	O
four	O
types	O
of	O
plists	O
:	O
OpenStep	B-Operating_System
text	O
,	O
GNUStep	B-Application
text	O
,	O
Apple	O
XML	B-Protocol
,	O
and	O
Apple	O
Binary	O
.	O
</s>
<s>
It	O
also	O
handles	O
UIDs	O
in	O
XML	B-Protocol
and	O
binary	O
formats	O
.	O
</s>
