<s>
Chakra	B-Language
is	O
a	O
proprietary	B-Application
JScript	B-Language
engine	O
developed	O
by	O
Microsoft	O
.	O
</s>
<s>
It	O
is	O
used	O
in	O
the	O
Internet	B-Application
Explorer	I-Application
web	B-Application
browser	I-Application
.	O
</s>
<s>
Microsoft	O
later	O
developed	O
a	O
new	O
JavaScript	B-Language
engine	I-Language
for	O
its	O
Microsoft	B-Application
Edge	I-Application
browser	B-Application
,	O
which	O
is	O
confusingly	O
also	O
called	O
Chakra	B-Language
.	O
</s>
<s>
Microsoft	B-Application
Edge	I-Application
switched	O
to	O
the	O
V8	B-Language
JavaScript	I-Language
engine	I-Language
in	O
2020	O
.	O
</s>
<s>
A	O
distinctive	O
feature	O
of	O
the	O
engine	O
is	O
that	O
it	O
JIT	O
compiles	O
scripts	O
on	O
a	O
separate	O
CPU	B-General_Concept
core	O
,	O
parallel	O
to	O
the	O
web	B-Application
browser	I-Application
.	O
</s>
<s>
Though	O
Microsoft	O
has	O
in	O
the	O
past	O
pointed	O
out	O
that	O
other	O
elements	O
,	O
such	O
as	O
rendering	O
and	O
marshalling	B-Application
,	O
are	O
just	O
as	O
important	O
for	O
a	O
browser	B-Application
's	O
overall	O
performance	O
,	O
their	O
improvements	O
to	O
the	O
engine	O
were	O
in	O
response	O
to	O
evolving	O
competing	O
browsers	B-Application
,	O
compared	O
to	O
which	O
IE8	O
was	O
lagging	O
behind	O
in	O
terms	O
of	O
client-side	O
script	O
processing	O
speed	O
.	O
</s>
<s>
SunSpider	O
tests	O
performed	O
on	O
November	O
18	O
,	O
2009	O
showed	O
the	O
PDC	O
version	O
of	O
IE9	O
executing	O
scripts	O
much	O
faster	O
than	O
IE8	O
,	O
but	O
slower	O
than	O
Firefox	B-Protocol
3.6	I-Protocol
,	O
Chrome	B-Application
4	O
,	O
and	O
WebKit	B-Language
Nightly	O
.	O
</s>
<s>
The	O
same	O
test	O
performed	O
on	O
March	O
15	O
,	O
2010	O
showed	O
the	O
first	O
IE9	O
Platform	O
Preview	O
(	O
using	O
the	O
then-current	O
version	O
of	O
Chakra	B-Language
)	O
to	O
be	O
faster	O
than	O
Firefox	B-Application
(	O
with	O
SpiderMonkey	B-Language
)	O
,	O
but	O
slower	O
than	O
Safari	B-Application
(	O
with	O
SquirrelFish	O
Extreme	O
)	O
,	O
Chrome	B-Application
(	O
with	O
V8	B-Language
)	O
,	O
and	O
Opera	B-Application
(	O
with	O
Carakan	B-Application
)	O
.	O
</s>
<s>
On	O
March	O
8	O
,	O
2011	O
,	O
Microsoft	O
published	O
results	O
showing	O
the	O
32-bit	O
Internet	B-Application
Explorer	I-Application
9	O
to	O
be	O
faster	O
than	O
Safari	B-Application
,	O
Firefox	B-Application
(	O
with	O
TraceMonkey	O
)	O
,	O
Chrome	B-Application
,	O
and	O
Opera	B-Application
.	O
</s>
<s>
March	O
2011	O
performance	O
tests	O
for	O
ZDNet	O
concluded	O
that	O
Internet	B-Application
Explorer	I-Application
9	O
(	O
32-bit	O
)	O
,	O
Chrome	B-Application
10	O
,	O
and	O
Firefox	B-Application
4	O
release	O
candidate	O
were	O
"	O
pretty	O
evenly	O
matched.	O
"	O
</s>
<s>
In	O
2012	O
,	O
subsequent	O
versions	O
of	O
Chakra	B-Language
,	O
such	O
as	O
the	O
version	O
included	O
in	O
Internet	B-Application
Explorer	I-Application
10	I-Application
,	O
introduced	O
additional	O
performance	O
changes	O
,	O
including	O
JIT	O
compilation	O
on	O
x64	B-Device
and	O
ARM	B-Architecture
architectures	I-Architecture
,	O
and	O
optimizations	O
related	O
to	O
floating	B-Algorithm
point	I-Algorithm
math	I-Algorithm
and	O
garbage	B-General_Concept
collection	I-General_Concept
.	O
</s>
