<s>
ZeroVM	B-Application
is	O
an	O
open	B-Application
source	I-Application
light-weight	O
virtualization	B-Operating_System
and	O
sandboxing	O
technology	O
.	O
</s>
<s>
It	O
virtualizes	O
a	O
single	O
process	O
using	O
the	O
Google	B-Application
Native	I-Application
Client	I-Application
platform	O
.	O
</s>
<s>
ZeroVM	B-Application
creates	O
a	O
sandbox	O
around	O
a	O
single	O
process	O
,	O
</s>
<s>
using	O
technology	O
based	O
on	O
Google	B-Application
Native	I-Application
Client	I-Application
(	O
NaCl	B-Application
)	O
.	O
</s>
<s>
The	O
programs	O
executed	O
in	O
ZeroVM	B-Application
must	O
first	O
be	O
cross-compiled	O
to	O
the	O
NaCl	B-Application
platform	O
.	O
</s>
<s>
ZeroVM	B-Application
can	O
only	O
execute	O
NaCl	B-Application
code	O
compiled	O
for	O
the	O
x86-64	B-Device
platform	O
,	O
not	O
the	O
portable	B-Application
Native	I-Application
Client	I-Application
(	O
PNaCl	O
)	O
format	O
.	O
</s>
<s>
Code	O
executed	O
in	O
ZeroVM	B-Application
cannot	O
call	O
normal	O
system	B-Operating_System
calls	I-Operating_System
and	O
initially	O
cannot	O
interact	O
with	O
the	O
host	O
environment	O
.	O
</s>
<s>
Outside	O
the	O
sandbox	O
,	O
a	O
channel	O
can	O
be	O
connected	O
to	O
a	O
local	O
file	O
,	O
to	O
a	O
pipe	O
,	O
or	O
to	O
another	O
ZeroVM	B-Application
instance	O
.	O
</s>
<s>
Inside	O
the	O
sandbox	O
,	O
the	O
program	O
sees	O
the	O
channel	O
as	O
a	O
file	B-Application
descriptor	I-Application
.	O
</s>
<s>
Programs	O
compiled	O
for	O
ZeroVM	B-Application
can	O
optionally	O
use	O
the	O
ZeroVM	B-Application
Runtime	O
library	O
called	O
ZRT	O
.	O
</s>
<s>
It	O
does	O
this	O
by	O
replacing	O
parts	O
of	O
the	B-Language
C	I-Language
standard	I-Language
library	I-Language
.	O
</s>
<s>
In	O
particular	O
,	O
ZRT	O
replaces	O
C	B-Language
file	I-Language
input/output	I-Language
functions	O
such	O
as	O
fopen	O
and	O
opendir	O
with	O
versions	O
that	O
operate	O
on	O
an	O
in-memory	O
filesystem	O
.	O
</s>
<s>
The	O
ZRT	O
also	O
replaces	O
C	B-Language
date	I-Language
and	I-Language
time	I-Language
functions	I-Language
such	O
as	O
time	O
to	O
give	O
programs	O
a	O
fixed	O
and	O
deterministic	O
environment	O
.	O
</s>
<s>
ZeroVM	B-Application
has	O
been	O
integrated	O
with	O
Swift	O
,	O
the	O
distributed	O
object	O
storage	O
component	O
of	O
OpenStack	B-Application
.	O
</s>
<s>
When	O
the	O
ZeroCloud	O
middleware	O
is	O
installed	O
into	O
Swift	O
,	O
a	O
client	O
can	O
make	O
a	O
request	O
to	O
Swift	O
containing	O
a	O
ZeroVM	B-Application
program	O
.	O
</s>
<s>
ZeroVM	B-Application
was	O
developed	O
by	O
LiteStack	O
,	O
an	O
Israeli	O
startup	O
.	O
</s>
<s>
The	O
first	O
commit	O
in	O
the	O
zerovm	B-Application
Git	B-Application
repository	O
was	O
added	O
in	O
November	O
2011	O
.	O
</s>
<s>
ZeroVM	B-Application
participated	O
in	O
Techstars	O
Cloud	O
2013	O
incubator	O
program	O
and	O
got	O
$	O
500,000	O
in	O
seed	O
funding	O
.	O
</s>
<s>
The	O
first	O
ZeroVM	B-Application
Design	O
Summit	O
was	O
held	O
in	O
January	O
2014	O
at	O
the	O
University	O
of	O
Texas	O
at	O
San	O
Antonio	O
.	O
</s>
