<s>
Rosetta	B-Operating_System
is	O
a	O
dynamic	O
binary	O
translator	O
developed	O
by	O
Apple	O
Inc	O
.	O
for	O
macOS	B-Application
,	O
an	O
application	O
compatibility	O
layer	O
between	O
different	O
instruction	B-General_Concept
set	I-General_Concept
architectures	I-General_Concept
.	O
</s>
<s>
The	O
name	O
is	O
a	O
reference	O
to	O
the	O
Rosetta	B-Operating_System
Stone	I-Operating_System
,	O
the	O
artifact	O
which	O
enabled	O
translation	O
of	O
Egyptian	O
hieroglyphs	O
.	O
</s>
<s>
The	O
first	O
version	O
of	O
Rosetta	B-Operating_System
,	O
introduced	O
in	O
2006	O
in	O
Mac	B-Application
OS	I-Application
X	I-Application
Tiger	I-Application
,	O
was	O
part	O
of	O
the	O
Mac	B-Device
transition	I-Device
from	I-Device
PowerPC	I-Device
processors	I-Device
to	I-Device
Intel	I-Device
processors	I-Device
,	O
allowing	O
PowerPC	B-Architecture
applications	O
to	O
run	O
on	O
Intel-based	B-Device
Macs	I-Device
.	O
</s>
<s>
The	O
second	O
version	O
,	O
introduced	O
in	O
2020	O
as	O
a	O
component	O
of	O
macOS	B-Operating_System
Big	I-Operating_System
Sur	I-Operating_System
,	O
is	O
part	O
of	O
the	O
Mac	B-Device
transition	I-Device
from	I-Device
Intel	I-Device
processors	I-Device
to	I-Device
Apple	I-Device
silicon	I-Device
,	O
allowing	O
Intel	B-Operating_System
applications	O
to	O
run	O
on	O
Apple	B-Device
silicon	I-Device
Macs	O
.	O
</s>
<s>
Macintosh	B-Device
has	O
used	O
CPUs	B-Device
with	O
several	O
different	O
instruction	B-General_Concept
set	I-General_Concept
architectures	I-General_Concept
:	O
the	O
Motorola	B-Device
68000	I-Device
series	I-Device
,	O
PowerPC	B-Architecture
,	O
Intel	B-Operating_System
x86	I-Operating_System
,	O
and	O
ARM64	B-Architecture
in	O
Apple	B-Device
silicon	I-Device
.	O
</s>
<s>
Each	O
instruction	B-General_Concept
set	I-General_Concept
architecture	I-General_Concept
is	O
incompatible	O
with	O
its	O
predecessor	O
,	O
necessitating	O
a	O
transition	O
plan	O
based	O
on	O
a	O
software	O
layer	O
to	O
emulate	B-Application
the	O
previous	O
instruction	B-General_Concept
set	I-General_Concept
on	O
the	O
succeeding	O
one	O
.	O
</s>
<s>
With	O
the	O
launch	O
of	O
Power	B-Device
Macintosh	I-Device
,	O
the	O
Mac	B-Device
68K	I-Device
emulator	I-Device
is	O
part	O
of	O
System	B-Operating_System
7.1.2	I-Operating_System
and	O
later	O
.	O
</s>
<s>
This	O
emulator	B-Application
uses	O
PowerPC	B-Architecture
features	O
and	O
is	O
embedded	O
at	O
the	O
lowest	O
levels	O
of	O
the	O
operating	O
system	O
,	O
integrated	O
with	O
the	O
Mac	B-Operating_System
OS	I-Operating_System
nanokernel	I-Operating_System
.	O
</s>
<s>
This	O
means	O
that	O
the	O
nanokernel	O
is	O
able	O
to	O
intercept	O
PowerPC	B-Architecture
interrupts	O
,	O
translate	O
them	O
to	O
68k	B-Device
interrupts	O
(	O
then	O
doing	O
a	O
mixed	O
mode	O
switch	O
,	O
if	O
necessary	O
)	O
,	O
and	O
then	O
execute	O
68k	B-Device
code	O
to	O
handle	O
the	O
interrupts	O
.	O
</s>
<s>
This	O
allows	O
68k	B-Device
and	O
PowerPC	B-Architecture
code	O
to	O
be	O
interspersed	O
within	O
the	O
same	O
fat	O
binary	O
.	O
</s>
<s>
Apple	O
launched	O
Rosetta	B-Operating_System
in	O
2006	O
upon	O
the	O
Mac	B-Device
transition	I-Device
to	I-Device
Intel	I-Device
processors	I-Device
from	O
PowerPC	B-Architecture
.	O
</s>
<s>
It	O
was	O
embedded	O
in	O
Mac	B-Application
OS	I-Application
X	I-Application
v10.4.4	I-Application
"	O
Tiger	O
"	O
,	O
the	O
version	O
that	O
was	O
released	O
with	O
the	O
first	O
Intel-based	B-Device
Macs	I-Device
,	O
and	O
allows	O
many	O
PowerPC	B-Architecture
applications	O
to	O
run	O
on	O
Intel-based	B-Device
Mac	I-Device
computers	O
without	O
modification	O
.	O
</s>
<s>
Rosetta	B-Operating_System
is	O
based	O
on	O
QuickTransit	O
technology	O
.	O
</s>
<s>
Rosetta	B-Operating_System
is	O
optionally	O
installable	O
in	O
Mac	B-Device
OS	I-Device
X	I-Device
v10.6	I-Device
"	O
Snow	B-Device
Leopard	I-Device
"	O
.	O
</s>
<s>
Rosetta	B-Operating_System
is	O
neither	O
included	O
nor	O
supported	O
in	O
Mac	B-Application
OS	I-Application
X	I-Application
v10.7	I-Application
"	O
Lion	B-Application
"	O
or	O
later	O
,	O
which	O
therefore	O
cannot	O
run	O
PowerPC	B-Architecture
applications	O
.	O
</s>
<s>
Because	O
of	O
the	O
greater	O
architectural	O
differences	O
between	O
Intel	B-Operating_System
and	O
PowerPC	B-Architecture
processors	I-Architecture
,	O
Rosetta	B-Operating_System
operates	O
at	O
a	O
higher	O
level	O
than	O
the	O
68000	O
emulator	B-Application
does	O
,	O
as	O
a	O
user-level	O
program	O
that	O
can	O
only	O
intercept	O
and	O
emulate	B-Application
user-level	O
code	O
.	O
</s>
<s>
It	O
translates	O
G3	B-Device
,	O
G4	B-General_Concept
,	O
and	O
AltiVec	B-General_Concept
instructions	O
,	O
but	O
not	O
G5	B-General_Concept
instructions	O
.	O
</s>
<s>
Although	O
most	O
commercial	O
software	O
for	O
PowerPC-based	O
Macs	O
was	O
compatible	O
with	O
these	O
requirements	O
(	O
G4	B-General_Concept
systems	O
were	O
still	O
widely	O
used	O
at	O
the	O
time	O
)	O
,	O
any	O
applications	O
that	O
relied	O
on	O
G5-specific	O
instructions	O
had	O
to	O
be	O
modified	O
by	O
their	O
developers	O
to	O
work	O
on	O
Rosetta-supported	O
Intel-based	B-Device
Macs	I-Device
.	O
</s>
<s>
Apple	O
advised	O
that	O
applications	O
with	O
heavy	O
user	O
interaction	O
but	O
low	O
computational	O
needs	O
(	O
such	O
as	O
word	B-General_Concept
processors	I-General_Concept
)	O
would	O
be	O
best	O
suited	O
to	O
use	O
with	O
Rosetta	B-Operating_System
,	O
and	O
applications	O
with	O
high	O
computational	O
needs	O
(	O
such	O
as	O
games	O
,	O
AutoCAD	B-Algorithm
,	O
or	O
Photoshop	B-Operating_System
)	O
would	O
not	O
.	O
</s>
<s>
Rosetta	B-Operating_System
also	O
does	O
not	O
support	O
the	O
following	O
:	O
</s>
<s>
In	O
2020	O
,	O
Apple	O
announced	O
Rosetta	B-Operating_System
2	O
would	O
be	O
bundled	O
with	O
macOS	B-Operating_System
Big	I-Operating_System
Sur	I-Operating_System
,	O
to	O
aid	O
in	O
the	O
Mac	B-Device
transition	I-Device
to	I-Device
Apple	I-Device
silicon	I-Device
.	O
</s>
<s>
The	O
software	O
permits	O
many	O
applications	O
compiled	O
exclusively	O
for	O
execution	O
on	O
x86-64-based	O
processors	O
to	O
be	O
translated	O
for	O
execution	O
on	O
Apple	B-Device
silicon	I-Device
.	O
</s>
<s>
To	O
install	O
Rosetta	B-Operating_System
2	O
on	O
an	O
Apple	B-Device
Silicon	I-Device
Mac	O
there	O
are	O
two	O
ways	O
to	O
do	O
it	O
:	O
either	O
by	O
using	O
the	O
Terminal	B-Application
to	O
install	O
the	O
program	O
directly	O
,	O
or	O
by	O
trying	O
to	O
open	O
an	O
application	O
compiled	O
for	O
x86	B-Operating_System
,	O
which	O
will	O
open	O
an	O
installation	O
window	O
.	O
</s>
<s>
In	O
addition	O
to	O
the	O
just-in-time	O
(	O
JIT	O
)	O
translation	O
support	O
,	O
Rosetta	B-Operating_System
2	O
offers	O
ahead-of-time	B-Application
compilation	I-Application
(	O
AOT	B-Application
)	O
,	O
with	O
the	O
x86-64	B-Device
code	O
fully	O
translated	O
,	O
just	O
once	O
,	O
when	O
an	O
application	O
without	O
a	O
universal	B-Operating_System
binary	I-Operating_System
is	O
installed	O
on	O
an	O
Apple	B-Device
silicon	I-Device
Mac	O
.	O
</s>
<s>
Rosetta	B-Operating_System
2	O
's	O
performance	O
has	O
been	O
praised	O
greatly	O
.	O
</s>
<s>
In	O
some	O
benchmarks	O
,	O
x86-64-only	O
programs	O
performed	O
better	O
under	O
Rosetta	B-Operating_System
2	O
on	O
a	O
Mac	O
with	O
an	O
Apple	O
M1	O
SOC	O
than	O
natively	O
on	O
a	O
Mac	O
with	O
an	O
Intel	O
x86-64	B-Device
processor	O
.	O
</s>
<s>
One	O
of	O
the	O
key	O
reasons	O
why	O
Rosetta	B-Operating_System
2	O
provides	O
such	O
high	O
level	O
of	O
translation	O
efficiency	O
is	O
the	O
support	O
of	O
x86-64	B-Device
memory	O
ordering	O
in	O
Apple	O
M1	O
SOC	O
.	O
</s>
<s>
Although	O
Rosetta	B-Operating_System
2	O
works	O
for	O
most	O
software	O
,	O
some	O
software	O
does	O
n't	O
work	O
at	O
all	O
or	O
is	O
reported	O
to	O
be	O
"	O
sluggish	O
"	O
.	O
</s>
<s>
Similar	O
to	O
the	O
first	O
version	O
,	O
Rosetta	B-Operating_System
2	O
does	O
not	O
normally	O
require	O
user	O
intervention	O
.	O
</s>
<s>
When	O
a	O
user	O
attempts	O
to	O
launch	O
an	O
x86-64-only	O
application	O
for	O
the	O
first	O
time	O
,	O
macOS	B-Application
prompts	O
them	O
to	O
install	O
Rosetta	B-Operating_System
2	O
if	O
it	O
is	O
not	O
already	O
available	O
.	O
</s>
<s>
Subsequent	O
launches	O
of	O
x86-64	B-Device
programs	O
will	O
execute	O
via	O
translation	O
automatically	O
.	O
</s>
<s>
An	O
option	O
also	O
exists	O
to	O
force	O
a	O
universal	B-Operating_System
binary	I-Operating_System
to	O
run	O
as	O
x86-64	B-Device
code	O
through	O
Rosetta	B-Operating_System
2	O
,	O
even	O
on	O
an	O
ARM-based	O
machine	O
.	O
</s>
<s>
Since	O
macOS	B-Operating_System
Ventura	I-Operating_System
,	O
users	O
running	O
virtual	B-Architecture
machines	I-Architecture
with	O
Linux	B-Application
as	O
a	O
guest	B-General_Concept
operating	I-General_Concept
system	I-General_Concept
,	O
can	O
make	O
use	O
of	O
Rosetta	B-Operating_System
2	O
to	O
run	O
x86-64	B-Device
code	O
compiled	O
for	O
Linux	B-Application
,	O
within	O
the	O
virtual	B-Architecture
machine	I-Architecture
.	O
</s>
<s>
Rosetta	B-Operating_System
2	O
works	O
as	O
a	O
runtime	O
binary	O
,	O
which	O
is	O
required	O
to	O
be	O
installed	O
on	O
the	O
guest	B-General_Concept
operating	I-General_Concept
system	I-General_Concept
.	O
</s>
<s>
There	O
have	O
been	O
instances	O
of	O
developers	O
installing	O
this	O
runtime	O
binary	O
on	O
third-party	O
hardware	O
,	O
provided	O
that	O
it	O
includes	O
a	O
CPU	B-Device
that	O
supports	O
at	O
least	O
the	O
ARMv8.2-A	O
instruction	B-General_Concept
set	I-General_Concept
,	O
though	O
some	O
developers	O
have	O
noted	O
that	O
it	O
might	O
violate	O
macOS	B-Application
's	O
licensing	O
agreements	O
,	O
since	O
the	O
runtime	O
is	O
bundled	O
within	O
Apple	O
's	O
Virtualization	O
framework	O
.	O
</s>
