<s>
A	O
compatibility	B-Application
mode	I-Application
is	O
a	O
software	O
mechanism	O
in	O
which	O
a	O
software	O
either	O
emulates	B-Application
an	O
older	O
version	O
of	O
software	O
,	O
or	O
mimics	O
another	O
operating	B-General_Concept
system	I-General_Concept
in	O
order	O
to	O
allow	O
older	O
or	O
incompatible	B-Application
software	I-Application
or	O
files	B-Operating_System
to	O
remain	O
compatible	O
with	O
the	O
computer	O
's	O
newer	O
hardware	B-Architecture
or	O
software	O
.	O
</s>
<s>
Examples	O
of	O
the	O
software	O
using	O
the	O
mode	O
are	O
operating	B-General_Concept
systems	I-General_Concept
and	O
Internet	B-Application
Explorer	I-Application
.	O
</s>
<s>
A	O
compatibility	B-Application
mode	I-Application
in	O
an	O
operating	B-General_Concept
system	I-General_Concept
is	O
a	O
software	O
mechanism	O
in	O
which	O
a	O
computer	O
's	O
operating	B-General_Concept
system	I-General_Concept
emulates	B-Application
an	O
older	O
processor	B-General_Concept
,	O
operating	B-General_Concept
system	I-General_Concept
,	O
and/or	O
hardware	B-Device
platform	I-Device
in	O
order	O
to	O
allow	O
older	O
software	O
to	O
remain	O
compatible	O
with	O
the	O
computer	O
's	O
newer	O
hardware	B-Architecture
or	O
software	O
.	O
</s>
<s>
This	O
differs	O
from	O
a	O
full-fledged	O
emulator	B-Application
in	O
that	O
an	O
emulator	B-Application
typically	O
creates	O
a	O
virtual	O
hardware	B-Architecture
architecture	O
on	O
the	O
host	O
system	O
,	O
rather	O
than	O
simply	O
translating	O
the	O
older	O
system	O
's	O
function	O
calls	O
into	O
calls	O
that	O
the	O
host	O
system	O
can	O
understand	O
.	O
</s>
<s>
Examples	O
include	O
Classic	O
Mode	O
in	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
and	O
compatibility	B-Application
mode	I-Application
in	O
Microsoft	B-Application
Windows	I-Application
,	O
which	O
both	O
allow	O
applications	O
designed	O
for	O
older	O
versions	O
of	O
the	O
operating	B-General_Concept
system	I-General_Concept
to	O
run	O
.	O
</s>
<s>
Other	O
examples	O
include	O
Wine	B-Application
to	O
run	O
Windows	O
programs	O
on	O
Linux	B-Application
/	O
OS	B-Operating_System
X	I-Operating_System
and	O
Mono	B-Application
to	O
run	O
.NET	B-Application
programs	O
on	O
various	O
Unix-like	B-Operating_System
systems	I-Operating_System
.	O
</s>
<s>
"	O
Compatibility	B-Application
View	I-Application
"	O
is	O
a	O
compatibility	B-Application
mode	I-Application
feature	O
of	O
the	O
web	B-Application
browser	I-Application
Internet	B-Application
Explorer	I-Application
in	O
version	O
8	O
and	O
later	O
.	O
</s>
<s>
When	O
active	O
,	O
Compatibility	B-Application
View	I-Application
forces	O
IE	O
to	O
display	O
the	O
webpage	O
in	O
Quirks	B-General_Concept
mode	I-General_Concept
as	O
if	O
the	O
page	O
were	O
being	O
viewed	O
in	O
IE7	B-Application
.	O
</s>
<s>
When	O
compatibility	B-Application
view	I-Application
is	O
not	O
activated	O
,	O
IE	O
is	O
said	O
to	O
be	O
running	O
in	O
native	O
mode	O
.	O
</s>
<s>
In	O
IE11	O
,	O
a	O
user	O
can	O
turn	O
on	O
compatibility	B-Application
mode	I-Application
for	O
a	O
web	O
site	O
by	O
clicking	O
the	O
Gears	O
icon	O
and	O
clicking	O
Compatibility	B-Application
View	I-Application
Settings	O
.	O
</s>
<s>
Internet	B-Application
Explorer	I-Application
8	I-Application
was	O
promoted	O
by	O
Microsoft	O
as	O
having	O
stricter	O
adherence	O
to	O
W3C	O
described	O
web	O
standards	O
than	O
Internet	B-Application
Explorer	I-Application
7	I-Application
.	O
</s>
<s>
As	O
a	O
result	O
,	O
as	O
in	O
every	O
IE	O
version	O
before	O
it	O
,	O
some	O
percentage	O
of	O
web	O
pages	O
coded	O
to	O
the	O
behavior	O
of	O
the	O
older	O
versions	O
would	O
break	O
in	O
IE8	B-Application
.	O
</s>
<s>
This	O
would	O
have	O
been	O
a	O
repetition	O
of	O
the	O
situation	O
with	O
IE7	B-Application
which	O
,	O
while	O
having	O
fixed	O
bugs	O
from	O
IE6	O
,	O
broke	O
pages	O
that	O
used	O
the	O
IE6-specific	O
hacks	O
to	O
work	O
around	O
its	O
non-compliance	O
.	O
</s>
<s>
To	O
avoid	O
this	O
situation	O
,	O
IE8	B-Application
implemented	O
a	O
form	O
of	O
version	B-Protocol
targeting	I-Protocol
whereby	O
a	O
page	O
could	O
be	O
authored	O
to	O
a	O
specific	O
version	O
of	O
a	O
browser	B-Application
using	O
the	O
X-UA-Compatible	O
declaration	O
either	O
as	O
a	O
meta	O
element	O
or	O
in	O
the	O
HTTP	B-Protocol
headers	I-Protocol
.	O
</s>
<s>
In	O
order	O
to	O
maintain	O
backwards	B-General_Concept
compatibility	I-General_Concept
,	O
sites	O
can	O
opt	O
into	O
IE7-like	O
handling	O
of	O
content	O
by	O
inserting	O
a	O
specially	O
created	O
meta	O
element	O
into	O
the	O
web	O
page	O
that	O
triggers	O
compatibility	B-Application
mode	I-Application
in	O
the	O
browser	B-Application
,	O
using	O
:	O
</s>
<s>
A	O
newer	O
version	O
of	O
the	O
browser	B-Application
than	O
the	O
page	O
was	O
coded	O
for	O
would	O
emulate	O
the	O
behavior	O
of	O
the	O
older	O
version	O
,	O
so	O
that	O
the	O
assumptions	O
the	O
page	O
made	O
about	O
the	O
browser	B-Application
's	O
behavior	O
hold	O
true	O
.	O
</s>
<s>
Microsoft	O
proposed	O
that	O
a	O
page	O
with	O
a	O
doctype	O
that	O
triggers	O
standards	B-General_Concept
mode	I-General_Concept
(	O
or	O
almost	O
standards	B-General_Concept
mode	I-General_Concept
)	O
in	O
IE7	B-Application
would	O
,	O
by	O
default	O
,	O
trigger	O
IE7-like	O
behavior	O
,	O
called	O
"	O
standards	B-General_Concept
mode	I-General_Concept
"	O
(	O
now	O
called	O
"	O
strict	B-General_Concept
mode	I-General_Concept
"	O
)	O
in	O
IE8	B-Application
and	O
future	O
versions	O
of	O
IE	O
.	O
</s>
<s>
The	O
new	O
features	O
of	O
IE8	B-Application
are	O
enabled	O
to	O
trigger	O
what	O
Microsoft	O
called	O
the	O
"	O
IE8	B-Application
standards	B-General_Concept
mode	I-General_Concept
"	O
(	O
now	O
called	O
"	O
standards	B-General_Concept
mode	I-General_Concept
"	O
)	O
.	O
</s>
<s>
Doctypes	O
that	O
trigger	O
quirks	B-General_Concept
mode	I-General_Concept
in	O
IE7	B-Application
will	O
continue	O
to	O
do	O
so	O
in	O
IE8	B-Application
.	O
</s>
<s>
Peter	O
Bright	O
of	O
Ars	O
Technica	O
claimed	O
that	O
the	O
idea	O
of	O
using	O
a	O
meta	O
tag	O
to	O
pick	O
a	O
specific	O
rendering	O
mode	O
fundamentally	O
misses	O
the	O
point	O
of	O
standards-based	O
development	O
but	O
positioned	O
the	O
issue	O
as	O
one	O
of	O
idealism	O
versus	O
pragmatism	O
in	O
web	O
development	O
,	O
noting	O
that	O
not	O
all	O
of	O
the	O
Web	O
is	O
maintained	O
,	O
and	O
that	O
"	O
demanding	O
that	O
web	O
developers	O
update	O
sites	O
to	O
ensure	O
they	O
continue	O
to	O
work	O
properly	O
in	O
any	O
future	O
browser	B-Application
version	O
is	O
probably	O
too	O
much	O
to	O
ask.	O
"	O
</s>
<s>
The	O
result	O
for	O
IE	B-Application
8	I-Application
Beta	O
1	O
was	O
that	O
it	O
could	O
render	O
three	O
modes	O
:	O
"	O
Quirks	O
,	O
"	O
"	O
Strict	O
,	O
"	O
and	O
"	O
Standard.	O
"	O
</s>
<s>
When	O
there	O
is	O
an	O
old	O
DOCTYPE	O
or	O
when	O
there	O
is	O
no	O
DOCTYPE	O
,	O
IE	O
renders	O
it	O
like	O
IE5	O
would	O
(	O
quirks	B-General_Concept
mode	I-General_Concept
)	O
.	O
</s>
<s>
When	O
a	O
special	O
meta	O
element	O
or	O
its	O
corresponding	O
HTTP	B-Protocol
header	I-Protocol
is	O
included	O
in	O
a	O
web	O
page	O
,	O
IE8	B-Application
will	O
render	O
that	O
page	O
like	O
IE7	B-Application
would	O
(	O
strict	B-General_Concept
mode	I-General_Concept
)	O
.	O
</s>
<s>
Otherwise	O
,	O
IE8	B-Application
renders	O
pages	O
with	O
its	O
own	O
engine	O
(	O
standard	O
mode	O
)	O
.	O
</s>
<s>
The	O
release	O
of	O
Internet	B-Application
Explorer	I-Application
8	I-Application
Beta	O
1	O
revealed	O
that	O
many	O
web	O
sites	O
do	O
not	O
work	O
in	O
this	O
new	O
standards	B-General_Concept
mode	I-General_Concept
.	O
</s>
<s>
Microsoft	O
maintains	O
a	O
list	O
of	O
websites	O
that	O
have	O
been	O
reported	O
to	O
have	O
problems	O
in	O
IE8	B-Application
's	O
standards	B-General_Concept
mode	I-General_Concept
,	O
known	O
as	O
the	O
compatibility	B-Application
view	I-Application
list	O
.	O
</s>
<s>
When	O
a	O
user	O
enables	O
this	O
list	O
IE8	B-Application
will	O
render	O
the	O
websites	O
in	O
the	O
list	O
using	O
its	O
compatibility	B-Application
view	I-Application
mode	O
.	O
</s>
<s>
The	O
Internet	B-Application
Explorer	I-Application
team	O
also	O
tests	O
the	O
websites	O
on	O
the	O
list	O
for	O
compatibility	O
issues	O
and	O
removes	O
those	O
where	O
none	O
are	O
found	O
.	O
</s>
