<s>
The	O
Android	B-Application
SDK	I-Application
is	O
a	O
software	B-Application
development	I-Application
kit	I-Application
that	O
includes	O
a	O
comprehensive	O
set	O
of	O
development	O
tools	O
.	O
</s>
<s>
These	O
include	O
a	O
debugger	B-Application
,	O
libraries	B-Library
,	O
a	O
handset	O
emulator	B-Application
based	O
on	O
QEMU	B-Application
,	O
documentation	O
,	O
sample	O
code	O
,	O
and	O
tutorials	O
.	O
</s>
<s>
Currently	O
supported	O
development	O
platforms	O
include	O
computers	O
running	O
Linux	B-Operating_System
(	O
any	O
modern	O
desktop	O
Linux	B-Operating_System
distribution	I-Operating_System
)	O
,	O
Mac	O
OS	O
X	O
10.5.8	O
or	O
later	O
,	O
and	O
Windows	B-Device
7	I-Device
or	O
later	O
.	O
</s>
<s>
,	O
the	O
SDK	B-Application
is	O
not	O
available	O
on	O
Android	O
itself	O
,	O
but	O
software	O
development	O
is	O
possible	O
by	O
using	O
specialized	O
Android	O
applications	O
.	O
</s>
<s>
Until	O
around	O
the	O
end	O
of	O
2014	O
,	O
the	O
officially-supported	O
integrated	B-Application
development	I-Application
environment	I-Application
(	O
IDE	B-Application
)	O
was	O
Eclipse	B-Application
using	O
the	O
Android	O
Development	O
Tools	O
(	O
ADT	O
)	O
Plugin	O
.	O
</s>
<s>
As	O
of	O
2015	O
,	O
Android	B-Application
Studio	I-Application
is	O
the	O
official	O
IDE	B-Application
;	O
however	O
,	O
developers	O
are	O
free	O
to	O
use	O
others	O
,	O
but	O
Google	B-Application
made	O
it	O
clear	O
that	O
ADT	O
was	O
officially	O
deprecated	O
since	O
the	O
end	O
of	O
2015	O
to	O
focus	O
on	O
Android	B-Application
Studio	I-Application
as	O
the	O
official	O
Android	O
IDE	B-Application
.	O
</s>
<s>
Additionally	O
,	O
developers	O
may	O
use	O
any	O
text	O
editor	O
to	O
edit	O
Java	B-Language
and	O
XML	O
files	O
,	O
then	O
use	O
command	B-Application
line	I-Application
tools	I-Application
(	O
Java	B-Language
Development	I-Language
Kit	I-Language
and	O
Apache	B-Application
Ant	I-Application
are	O
required	O
)	O
to	O
create	O
,	O
build	O
and	O
debug	O
Android	O
applications	O
as	O
well	O
as	O
control	O
attached	O
Android	O
devices	O
(	O
e.g.	O
,	O
triggering	O
a	O
reboot	O
,	O
installing	O
software	O
package(s )	O
remotely	O
)	O
.	O
</s>
<s>
Enhancements	O
to	O
Android	O
's	O
SDK	B-Application
go	O
hand-in-hand	O
with	O
the	O
overall	O
Android	O
platform	O
development	O
.	O
</s>
<s>
The	O
SDK	B-Application
also	O
supports	O
older	O
versions	O
of	O
the	O
Android	O
platform	O
in	O
case	O
developers	O
wish	O
to	O
target	O
their	O
applications	O
at	O
older	O
devices	O
.	O
</s>
<s>
Android	O
applications	O
are	O
packaged	O
in	O
.apk	B-Application
format	O
and	O
stored	O
under	O
/data/app	O
folder	O
on	O
the	O
Android	O
OS	O
(	O
the	O
folder	O
is	O
accessible	O
only	O
to	O
the	O
root	O
user	O
for	O
security	O
reasons	O
)	O
.	O
</s>
<s>
APK	B-Application
package	O
contains	O
.dex	B-Application
files	O
(	O
compiled	O
byte	O
code	O
files	O
called	O
Dalvik	B-Application
executables	O
)	O
,	O
resource	O
files	O
,	O
etc	O
.	O
</s>
<s>
The	O
Android	B-Application
SDK	I-Application
Platform	O
Tools	O
are	O
a	O
separately	O
downloadable	O
subset	O
of	O
the	O
full	O
SDK	B-Application
,	O
consisting	O
of	O
command-line	B-Application
tools	I-Application
such	O
as	O
Android	B-Application
Debug	I-Application
Bridge	I-Application
and	O
fastboot	B-Application
.	O
</s>
