<s>
macOS	B-Operating_System
High	I-Operating_System
Sierra	I-Operating_System
(	O
version	O
10.13	O
)	O
is	O
the	O
fourteenth	O
major	O
release	O
of	O
macOS	B-Application
,	O
Apple	O
Inc.	O
'	O
s	O
desktop	O
operating	O
system	O
for	O
Macintosh	B-Device
computers	O
.	O
</s>
<s>
macOS	B-Operating_System
High	I-Operating_System
Sierra	I-Operating_System
was	O
announced	O
at	O
the	O
WWDC	O
2017	O
on	O
June	O
5	O
,	O
2017	O
and	O
was	O
released	O
on	O
September	O
25	O
,	O
2017	O
.	O
</s>
<s>
The	O
name	O
"	O
High	B-Operating_System
Sierra	I-Operating_System
"	O
refers	O
to	O
the	O
High	B-Operating_System
Sierra	I-Operating_System
region	O
in	O
California	O
.	O
</s>
<s>
Its	O
name	O
signified	O
its	O
goal	O
to	O
be	O
a	O
refinement	O
of	O
the	O
previous	O
macOS	B-Application
version	O
,	O
macOS	B-Operating_System
Sierra	I-Operating_System
,	O
focused	O
on	O
performance	O
improvements	O
and	O
technical	O
updates	O
rather	O
than	O
features	O
.	O
</s>
<s>
This	O
makes	O
it	O
similar	O
to	O
previous	O
macOS	B-Application
releases	O
Snow	B-Device
Leopard	I-Device
,	O
Mountain	B-Operating_System
Lion	I-Operating_System
and	O
El	B-Operating_System
Capitan	I-Operating_System
.	O
</s>
<s>
Among	O
the	O
apps	O
with	O
notable	O
changes	O
are	O
Photos	B-Application
and	O
Safari	B-Application
.	O
</s>
<s>
When	O
macOS	B-Operating_System
High	I-Operating_System
Sierra	I-Operating_System
was	O
released	O
,	O
it	O
supported	O
all	O
Macs	O
that	O
can	O
run	O
macOS	B-Operating_System
Sierra	I-Operating_System
:	O
</s>
<s>
Macs	O
that	O
were	O
released	O
after	O
High	B-Operating_System
Sierra	I-Operating_System
was	O
released	O
,	O
with	O
High	B-Operating_System
Sierra	I-Operating_System
as	O
the	O
initial	O
operating	O
major	O
release	O
,	O
are	O
:	O
</s>
<s>
macOS	B-Operating_System
High	I-Operating_System
Sierra	I-Operating_System
requires	O
at	O
least	O
2	O
GB	O
of	O
RAM	O
and	O
20.12	O
GB	O
of	O
available	O
disk	O
space	O
.	O
</s>
<s>
It	O
is	O
possible	O
to	O
install	O
High	B-Operating_System
Sierra	I-Operating_System
on	O
many	O
older	O
Macintosh	B-Device
computers	O
that	O
are	O
not	O
officially	O
supported	O
by	O
Apple	O
.	O
</s>
<s>
Apple	B-Application
File	I-Application
System	I-Application
(	O
APFS	B-Application
)	O
replaces	O
HFS	B-Application
Plus	I-Application
as	O
the	O
default	O
file	B-Application
system	I-Application
in	O
macOS	B-Application
for	O
the	O
first	O
time	O
with	O
High	B-Operating_System
Sierra	I-Operating_System
.	O
</s>
<s>
It	O
supports	O
64‑bit	O
inode	B-Application
numbers	I-Application
,	O
is	O
designed	O
for	O
flash	B-Device
memory	I-Device
,	O
and	O
is	O
designed	O
to	O
speed	O
up	O
common	O
tasks	O
like	O
duplicating	O
a	O
file	O
and	O
finding	O
the	O
size	O
of	O
a	O
folder	O
's	O
contents	O
.	O
</s>
<s>
Metal	B-Library
,	O
Apple	O
's	O
low-level	O
graphics	O
API	O
,	O
has	O
been	O
updated	O
to	O
Metal	B-Library
2	O
.	O
</s>
<s>
It	O
includes	O
virtual-reality	B-Application
and	O
machine-learning	O
features	O
,	O
as	O
well	O
as	O
support	O
for	O
external	B-Architecture
GPUs	I-Architecture
.	O
</s>
<s>
The	O
system	O
's	O
windowing	O
system	O
,	O
Quartz	O
Compositor	O
,	O
supports	O
Metal	B-Library
2	O
.	O
</s>
<s>
macOS	B-Operating_System
High	I-Operating_System
Sierra	I-Operating_System
adds	O
support	O
for	O
High	B-Algorithm
Efficiency	I-Algorithm
Video	I-Algorithm
Coding	I-Algorithm
(	O
HEVC	B-Algorithm
)	O
,	O
with	O
hardware	B-General_Concept
acceleration	I-General_Concept
where	O
available	O
,	O
as	O
well	O
as	O
support	O
for	O
High	O
Efficiency	O
Image	O
File	O
Format	O
(	O
HEIF	O
)	O
.	O
</s>
<s>
Macs	O
with	O
the	O
Intel	B-Device
Kaby	I-Device
Lake	I-Device
processor	O
offer	O
hardware	O
support	O
for	O
Main	O
10	O
profile	O
10-bit	O
hardware	O
decoding	O
,	O
those	O
with	O
the	O
Intel	B-Architecture
Skylake	I-Architecture
processor	O
support	O
Main	O
profile	O
8-bit	O
hardware	O
decoding	O
,	O
and	O
those	O
with	O
AMD	B-Device
Radeon	I-Device
400	I-Device
series	I-Device
graphics	O
also	O
support	O
full	O
HEVC	B-Algorithm
decoding	O
.	O
</s>
<s>
In	O
addition	O
,	O
audio	O
codecs	O
FLAC	B-Application
and	O
Opus	B-Algorithm
are	O
also	O
supported	O
,	O
but	O
not	O
in	O
iTunes	B-Operating_System
.	O
</s>
<s>
HEVC	B-Algorithm
hardware	B-General_Concept
acceleration	I-General_Concept
requires	O
a	O
Mac	O
with	O
a	O
sixth-generation	B-Architecture
Intel	O
processor	O
or	O
newer	O
(	O
late	O
2015	O
27-inch	O
iMac	B-Device
,	O
mid	O
2017	O
21.5-inch	O
iMac	B-Device
,	O
early	O
2016	O
MacBook	B-Device
,	O
late	O
2016	O
MacBook	B-Device
Pro	I-Device
or	O
iMac	B-Device
Pro	I-Device
)	O
.	O
</s>
<s>
Kernel	B-Application
extensions	I-Application
(	O
"	O
kexts	B-Application
"	O
)	O
will	O
require	O
explicit	O
approval	O
by	O
the	O
user	O
before	O
being	O
able	O
to	O
run	O
.	O
</s>
<s>
The	O
time	O
service	O
ntpd	B-Protocol
was	O
replaced	O
with	O
timed	B-Protocol
for	O
the	O
time	O
synchronization	O
.	O
</s>
<s>
The	O
FTP	B-Protocol
and	O
telnet	B-Protocol
command	O
line	O
programs	O
were	O
removed	O
.	O
</s>
<s>
Caching	O
Server	O
,	O
File	O
Sharing	O
Server	O
,	O
and	O
Time	O
Machine	O
Server	O
,	O
features	O
that	O
were	O
previously	O
part	O
of	O
macOS	B-Operating_System
Server	I-Operating_System
,	O
are	O
now	O
provided	O
as	O
part	O
of	O
the	O
OS	O
.	O
</s>
<s>
The	O
10.13.4	O
update	O
added	O
support	O
for	O
external	O
graphics	B-Architecture
processors	I-Architecture
for	O
Macs	O
equipped	O
with	O
Thunderbolt	B-Protocol
3	O
ports	O
.	O
</s>
<s>
The	O
update	O
discontinued	O
support	O
for	O
external	O
graphics	B-Architecture
processors	I-Architecture
in	O
2015	O
or	O
older	O
Macs	O
,	O
equipped	O
with	O
Thunderbolt	B-Protocol
1	O
and	O
2	O
ports	O
.	O
</s>
<s>
Starting	O
with	O
10.13.4	O
,	O
when	O
a	O
32-bit	O
app	O
is	O
opened	O
,	O
users	O
get	O
a	O
one-time	O
warning	O
about	O
its	O
future	O
incompatibility	O
with	O
the	O
macOS	B-Application
operating	O
system	O
.	O
</s>
<s>
Apple	O
announced	O
the	O
original	O
Final	O
Cut	O
Studio	O
suite	O
of	O
programs	O
will	O
not	O
work	O
on	O
High	B-Operating_System
Sierra	I-Operating_System
.	O
</s>
<s>
macOS	B-Operating_System
High	I-Operating_System
Sierra	I-Operating_System
gives	O
Photos	B-Application
an	O
updated	O
sidebar	O
and	O
new	O
editing	O
tools	O
.	O
</s>
<s>
Photos	B-Application
synchronizes	O
tagged	O
People	O
with	O
iOS	B-Operating_System
11	I-Operating_System
.	O
</s>
<s>
Mail	O
has	O
improved	O
Spotlight	B-Application
search	O
with	O
Top	O
Hits	O
.	O
</s>
<s>
macOS	B-Operating_System
High	I-Operating_System
Sierra	I-Operating_System
includes	O
Safari	B-Application
11	O
.	O
</s>
<s>
Safari	B-Application
11	O
has	O
a	O
new	O
"	O
Intelligent	O
Tracking	O
Prevention	O
"	O
feature	O
that	O
uses	O
machine	O
learning	O
to	O
block	O
third	O
parties	O
from	O
tracking	O
the	O
user	O
's	O
actions	O
.	O
</s>
<s>
Safari	B-Application
can	O
also	O
block	O
auto	O
playing	O
videos	O
from	O
playing	O
.	O
</s>
<s>
Safari	B-Application
11	O
also	O
supports	O
WebAssembly	B-Language
.	O
</s>
<s>
The	O
last	O
version	O
of	O
Safari	B-Application
that	O
High	B-Operating_System
Sierra	I-Operating_System
supports	O
is	O
13.1.2	O
.	O
</s>
