<s>
A	O
computing	B-Device
platform	I-Device
or	O
digital	O
platform	O
is	O
an	O
environment	O
in	O
which	O
a	O
piece	O
of	O
software	O
is	O
executed	O
.	O
</s>
<s>
It	O
may	O
be	O
the	O
hardware	B-Architecture
or	O
the	O
operating	B-General_Concept
system	I-General_Concept
(	O
OS	O
)	O
,	O
even	O
a	O
web	B-Application
browser	I-Application
and	O
associated	O
application	B-Application
programming	I-Application
interfaces	I-Application
,	O
or	O
other	O
underlying	O
software	O
,	O
as	O
long	O
as	O
the	O
program	B-Language
code	I-Language
is	O
executed	O
with	O
it	O
.	O
</s>
<s>
Computing	B-Device
platforms	I-Device
have	O
different	O
abstraction	B-Application
levels	O
,	O
including	O
a	O
computer	B-General_Concept
architecture	I-General_Concept
,	O
an	O
OS	O
,	O
or	O
runtime	B-Library
libraries	I-Library
.	O
</s>
<s>
A	O
computing	B-Device
platform	I-Device
is	O
the	O
stage	O
on	O
which	O
computer	O
programs	O
can	O
run	O
.	O
</s>
<s>
A	O
platform	O
can	O
be	O
seen	O
both	O
as	O
a	O
constraint	O
on	O
the	O
software	O
development	O
process	O
,	O
in	O
that	O
different	O
platforms	B-Device
provide	O
different	O
functionality	O
and	O
restrictions	O
;	O
and	O
as	O
an	O
assistant	O
to	O
the	O
development	O
process	O
,	O
in	O
that	O
they	O
provide	O
low-level	O
functionality	O
ready-made	O
.	O
</s>
<s>
For	O
example	O
,	O
an	O
OS	O
may	O
be	O
a	O
platform	O
that	O
abstracts	O
the	O
underlying	O
differences	O
in	O
hardware	B-Architecture
and	O
provides	O
a	O
generic	O
command	O
for	O
saving	O
files	O
or	O
accessing	O
the	O
network	B-Architecture
.	O
</s>
<s>
Platforms	B-Device
may	O
also	O
include	O
:	O
</s>
<s>
Hardware	B-Architecture
alone	O
,	O
in	O
the	O
case	O
of	O
small	O
embedded	B-Architecture
systems	I-Architecture
.	O
</s>
<s>
Embedded	B-Architecture
systems	I-Architecture
can	O
access	O
hardware	B-Architecture
directly	O
,	O
without	O
an	O
OS	O
;	O
this	O
is	O
referred	O
to	O
as	O
running	O
on	O
"	O
bare	O
metal	O
"	O
.	O
</s>
<s>
A	O
browser	B-Application
in	O
the	O
case	O
of	O
web-based	O
software	O
.	O
</s>
<s>
The	O
browser	B-Application
itself	O
runs	O
on	O
a	O
hardware+OS	O
platform	O
,	O
but	O
this	O
is	O
not	O
relevant	O
to	O
software	O
running	O
within	O
the	O
browser	B-Application
.	O
</s>
<s>
An	O
application	O
,	O
such	O
as	O
a	O
spreadsheet	O
or	O
word	O
processor	O
,	O
which	O
hosts	O
software	O
written	O
in	O
an	O
application-specific	O
scripting	B-Language
language	I-Language
,	O
such	O
as	O
an	O
Excel	O
macro	O
.	O
</s>
<s>
This	O
can	O
be	O
extended	O
to	O
writing	O
fully-fledged	O
applications	O
with	O
the	O
Microsoft	B-Application
Office	I-Application
suite	I-Application
as	O
a	O
platform	O
.	O
</s>
<s>
Software	B-Architecture
frameworks	I-Architecture
that	O
provide	O
ready-made	O
functionality	O
.	O
</s>
<s>
Cloud	B-Architecture
computing	I-Architecture
and	O
Platform	B-Application
as	I-Application
a	I-Application
Service	I-Application
.	O
</s>
<s>
Extending	O
the	O
idea	O
of	O
a	O
software	B-Architecture
framework	I-Architecture
,	O
these	O
allow	O
application	O
developers	O
to	O
build	O
software	O
out	O
of	O
components	O
that	O
are	O
hosted	O
not	O
by	O
the	O
developer	O
,	O
but	O
by	O
the	O
provider	O
,	O
with	O
internet	O
communication	O
linking	O
them	O
together	O
.	O
</s>
<s>
The	O
social	O
networking	O
sites	O
Twitter	B-Application
and	O
Facebook	B-Application
are	O
also	O
considered	O
development	O
platforms	B-Device
.	O
</s>
<s>
A	O
virtual	B-Architecture
machine	I-Architecture
(	O
VM	B-Application
)	O
such	O
as	O
the	O
Java	B-Language
virtual	I-Language
machine	I-Language
or	O
.NET	B-Application
CLR	O
.	O
</s>
<s>
Applications	O
are	O
compiled	O
into	O
a	O
format	O
similar	O
to	O
machine	O
code	O
,	O
known	O
as	O
bytecode	O
,	O
which	O
is	O
then	O
executed	O
by	O
the	O
VM	B-Application
.	O
</s>
<s>
A	O
virtualized	B-General_Concept
version	O
of	O
a	O
complete	O
system	O
,	O
including	O
virtualized	B-General_Concept
hardware	B-Architecture
,	O
OS	O
,	O
software	O
,	O
and	O
storage	O
.	O
</s>
<s>
For	O
instance	O
,	O
a	O
Java	B-Device
program	O
has	O
to	O
be	O
written	O
to	O
use	O
the	O
Java	B-Language
virtual	I-Language
machine	I-Language
(	O
JVM	B-Language
)	O
and	O
associated	O
libraries	O
as	O
a	O
platform	O
but	O
does	O
not	O
have	O
to	O
be	O
adapted	O
to	O
run	O
for	O
the	O
Windows	O
,	O
Linux	B-Application
or	O
Macintosh	O
OS	O
platforms	B-Device
.	O
</s>
<s>
However	O
,	O
the	O
JVM	B-Language
,	O
the	O
layer	O
beneath	O
the	O
application	O
,	O
does	O
have	O
to	O
be	O
built	O
separately	O
for	O
each	O
OS	O
.	O
</s>
<s>
Mozilla	O
WebExtensions	O
API	B-Application
is	O
modeled	O
after	O
Google	B-Application
Chrome	I-Application
's	O
API	B-Application
.	O
</s>
<s>
Thus	O
Firefox	O
extensions	O
are	O
now	O
largely	O
compatible	O
with	O
their	O
Chrome	B-Application
counterparts	O
.	O
</s>
