<s>
9P	B-Operating_System
(	O
or	O
the	O
Plan	B-Operating_System
9	I-Operating_System
Filesystem	I-Operating_System
Protocol	I-Operating_System
or	O
Styx	B-Operating_System
)	O
is	O
a	O
network	B-Architecture
protocol	O
developed	O
for	O
the	O
Plan	B-Operating_System
9	I-Operating_System
from	I-Operating_System
Bell	I-Operating_System
Labs	I-Operating_System
distributed	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
as	O
the	O
means	O
of	O
connecting	O
the	O
components	O
of	O
a	O
Plan	B-Operating_System
9	I-Operating_System
system	O
.	O
</s>
<s>
Files	O
are	O
key	O
objects	O
in	O
Plan	B-Operating_System
9	I-Operating_System
.	O
</s>
<s>
They	O
represent	O
windows	O
,	O
network	B-Architecture
connections	O
,	O
processes	B-Operating_System
,	O
and	O
almost	O
anything	O
else	O
available	O
in	O
the	O
operating	O
system	O
.	O
</s>
<s>
9P	B-Operating_System
was	O
revised	O
for	O
the	O
4th	O
edition	O
of	O
Plan	B-Operating_System
9	I-Operating_System
under	O
the	O
name	O
9P2000	B-Operating_System
,	O
containing	O
various	O
improvements	O
.	O
</s>
<s>
The	O
latest	O
version	O
of	O
the	O
Inferno	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
also	O
uses	O
9P2000	B-Operating_System
.	O
</s>
<s>
The	O
Inferno	B-Operating_System
file	O
protocol	O
was	O
originally	O
called	O
Styx	B-Operating_System
,	O
but	O
technically	O
it	O
has	O
always	O
been	O
a	O
variant	O
of	O
9P	B-Operating_System
.	O
</s>
<s>
A	O
server	O
implementation	O
of	O
9P	B-Operating_System
for	O
Unix	O
,	O
called	O
u9fs	O
,	O
is	O
included	O
in	O
the	O
Plan	B-Operating_System
9	I-Operating_System
distribution	O
.	O
</s>
<s>
A	O
9P	B-Operating_System
OS	B-Operating_System
X	I-Operating_System
client	O
kernel	B-Application
extension	I-Application
is	O
provided	O
by	O
Mac9P	O
.	O
</s>
<s>
A	O
kernel	O
client	O
driver	O
implementing	O
9P	B-Operating_System
with	O
some	O
extensions	O
for	O
Linux	B-Application
is	O
part	O
of	O
the	O
v9fs	B-Application
project	O
.	O
</s>
<s>
9P	B-Operating_System
and	O
its	O
derivatives	O
have	O
also	O
found	O
application	O
in	O
embedded	O
environments	O
,	O
such	O
as	O
the	O
Styx	B-Operating_System
on	O
a	O
Brick	O
project	O
.	O
</s>
<s>
Many	O
of	O
Plan	B-Operating_System
9	I-Operating_System
's	O
applications	O
take	O
the	O
form	O
of	O
9P	B-Operating_System
file	O
servers	O
.	O
</s>
<s>
Outside	O
of	O
Plan	B-Operating_System
9	I-Operating_System
,	O
the	O
9P	B-Operating_System
protocol	O
is	O
still	O
used	O
when	O
a	O
lightweight	O
remote	O
filesystem	O
is	O
required	O
:	O
</s>
<s>
NixOS	O
:	O
a	O
purely	O
functional	O
and	O
declarative	O
Linux	B-Application
distribution	O
can	O
rebuild	O
itself	O
inside	O
a	O
virtual	B-Architecture
machine	I-Architecture
,	O
where	O
the	O
client	O
uses	O
9P	B-Operating_System
to	O
mount	O
the	O
package	O
store	O
directory	O
of	O
the	O
host	O
.	O
</s>
<s>
Windows	O
Subsystem	O
for	O
Linux	B-Application
:	O
since	O
Windows	O
10	O
version	O
1903	O
,	O
the	O
subsystem	O
implements	O
9P	B-Operating_System
as	O
a	O
server	O
and	O
the	O
host	O
Windows	O
operating	O
system	O
acts	O
as	O
a	O
client	O
.	O
</s>
