<s>
Keyhole	B-Application
Markup	I-Application
Language	I-Application
(	O
KML	B-Application
)	O
is	O
an	O
XML	B-Protocol
notation	O
for	O
expressing	O
geographic	O
annotation	O
and	O
visualization	O
within	O
two-dimensional	O
maps	O
and	O
three-dimensional	O
Earth	O
browsers	O
.	O
</s>
<s>
KML	B-Application
was	O
developed	O
for	O
use	O
with	O
Google	B-Application
Earth	I-Application
,	O
which	O
was	O
originally	O
named	O
Keyhole	O
Earth	B-Application
Viewer	I-Application
.	O
</s>
<s>
It	O
was	O
created	O
by	O
Keyhole	O
,	O
Inc	O
,	O
which	O
was	O
acquired	O
by	O
Google	B-Application
in	O
2004	O
.	O
</s>
<s>
KML	B-Application
became	O
an	O
international	O
standard	O
of	O
the	O
Open	O
Geospatial	O
Consortium	O
in	O
2008	O
.	O
</s>
<s>
Google	B-Application
Earth	I-Application
was	O
the	O
first	O
program	O
able	O
to	O
view	O
and	O
graphically	O
edit	O
KML	B-Application
files	O
,	O
but	O
other	O
projects	O
such	O
as	O
Marble	B-Application
have	O
added	O
KML	B-Application
support	O
.	O
</s>
<s>
The	O
KML	B-Application
file	O
specifies	O
a	O
set	O
of	O
features	O
(	O
place	O
marks	O
,	O
images	O
,	O
polygons	O
,	O
3D	O
models	O
,	O
textual	O
descriptions	O
,	O
etc	O
.	O
)	O
</s>
<s>
that	O
can	O
be	O
displayed	O
on	O
maps	O
in	O
geospatial	B-Application
software	I-Application
implementing	O
the	O
KML	B-Application
encoding	O
.	O
</s>
<s>
KML	B-Application
shares	O
some	O
of	O
the	O
same	O
structural	O
grammar	O
as	O
Geography	O
Markup	O
Language	O
(	O
GML	O
)	O
.	O
</s>
<s>
Some	O
KML	B-Application
information	O
cannot	O
be	O
viewed	O
in	O
Google	B-Application
Maps	O
or	O
Mobile	O
.	O
</s>
<s>
KML	B-Application
files	O
are	O
very	O
often	O
distributed	O
as	O
KMZ	O
files	O
,	O
which	O
are	O
zipped	B-General_Concept
KML	B-Application
files	O
with	O
a	O
.kmz	B-Application
extension	O
.	O
</s>
<s>
The	O
contents	O
of	O
a	O
KMZ	O
file	O
are	O
a	O
single	O
root	O
KML	B-Application
document	O
(	O
notionally	O
"	O
doc.kml	O
"	O
)	O
and	O
optionally	O
any	O
overlays	O
,	O
images	O
,	O
icons	O
,	O
and	O
COLLADA	O
3D	O
models	O
referenced	O
in	O
the	O
KML	B-Application
including	O
network-linked	O
KML	B-Application
files	O
.	O
</s>
<s>
The	O
root	O
KML	B-Application
document	O
by	O
convention	O
is	O
a	O
file	O
named	O
"	O
doc.kml	O
"	O
at	O
the	O
root	O
directory	O
level	O
,	O
which	O
is	O
the	O
file	O
loaded	O
upon	O
opening	O
.	O
</s>
<s>
By	O
convention	O
the	O
root	O
KML	B-Application
document	O
is	O
at	O
root	O
level	O
and	O
referenced	O
files	O
are	O
in	O
subdirectories	O
(	O
e.g.	O
</s>
<s>
An	O
example	O
KML	B-Application
document	O
is	O
:	O
</s>
<s>
The	O
MIME	B-Application
type	I-Application
associated	O
with	O
KML	B-Application
is	O
application/vnd.google	O
-earth.kml	O
+xml	O
;	O
the	O
MIME	B-Application
type	I-Application
associated	O
with	O
KMZ	O
is	O
application/vnd.google	O
-earth.kmz	O
.	O
</s>
<s>
For	O
its	O
reference	O
system	O
,	O
KML	B-Application
uses	O
3D	O
geographic	O
coordinates	O
:	O
longitude	O
,	O
latitude	O
,	O
and	O
altitude	O
,	O
in	O
that	O
order	O
,	O
with	O
negative	O
values	O
for	O
west	O
,	O
south	O
,	O
and	O
below	O
mean	O
sea	O
level	O
.	O
</s>
<s>
A	O
formal	O
definition	O
of	O
the	O
coordinate	O
reference	O
system	O
(	O
encoded	O
as	O
GML	O
)	O
used	O
by	O
KML	B-Application
is	O
contained	O
in	O
the	O
OGC	O
KML	B-Application
2.2	O
Specification	O
.	O
</s>
<s>
The	O
KML	B-Application
2.2	O
specification	O
was	O
submitted	O
to	O
the	O
Open	O
Geospatial	O
Consortium	O
to	O
assure	O
its	O
status	O
as	O
an	O
open	O
standard	O
for	O
all	O
geobrowsers	B-Application
.	O
</s>
<s>
In	O
November	O
2007	O
a	O
new	O
KML	B-Application
2.2	O
Standards	O
Working	O
Group	O
was	O
established	O
within	O
OGC	O
to	O
formalize	O
KML	B-Application
2.2	O
as	O
an	O
OGC	O
standard	O
.	O
</s>
<s>
The	O
OGC	O
KML	B-Application
Standards	O
Working	O
Group	O
finished	O
working	O
on	O
change	O
requests	O
to	O
KML	B-Application
2.2	O
and	O
incorporated	O
accepted	O
changes	O
into	O
the	O
KML	B-Application
2.3	O
standard	O
.	O
</s>
<s>
The	O
official	O
OGC	O
KML	B-Application
2.3	O
standard	O
was	O
published	O
on	O
August	O
4	O
,	O
2015	O
.	O
</s>
