<s>
In	O
computer	B-General_Concept
science	I-General_Concept
,	O
a	O
synthetic	B-Application
file	I-Application
system	I-Application
or	O
a	O
pseudo	B-Application
file	I-Application
system	I-Application
is	O
a	O
hierarchical	O
interface	O
to	O
non-file	O
objects	O
that	O
appear	O
as	O
if	O
they	O
were	O
regular	O
files	O
in	O
the	O
tree	O
of	O
a	O
disk-based	O
or	O
long-term-storage	O
file	B-Application
system	I-Application
.	O
</s>
<s>
These	O
non-file	O
objects	O
may	O
be	O
accessed	O
with	O
the	O
same	O
system	B-Operating_System
calls	I-Operating_System
or	O
utility	B-Application
programs	I-Application
as	O
regular	O
files	O
and	O
directories	B-Application
.	O
</s>
<s>
The	O
benefit	O
of	O
synthetic	B-Application
file	I-Application
systems	I-Application
is	O
that	O
well-known	O
file	B-Application
system	I-Application
semantics	O
can	O
be	O
reused	O
for	O
a	O
universal	O
and	O
easily	O
implementable	O
approach	O
to	O
interprocess	B-Operating_System
communication	I-Operating_System
.	O
</s>
<s>
Clients	O
can	O
use	O
such	O
a	O
file	B-Application
system	I-Application
to	O
perform	O
simple	O
file	O
operations	O
on	O
its	O
nodes	O
and	O
do	O
not	O
have	O
to	O
implement	O
complex	O
message	B-Architecture
encoding	I-Architecture
and	I-Architecture
passing	I-Architecture
methods	O
and	O
other	O
aspects	O
of	O
protocol	B-General_Concept
engineering	I-General_Concept
.	O
</s>
<s>
For	O
most	O
operations	O
,	O
common	O
file	O
utilities	O
can	O
be	O
used	O
,	O
so	O
even	O
scripting	B-Language
is	O
quite	O
easy	O
.	O
</s>
<s>
This	O
is	O
commonly	O
known	O
as	O
everything	B-Application
is	I-Application
a	I-Application
file	I-Application
and	O
is	O
generally	O
regarded	O
to	O
have	O
originated	O
from	O
Unix	B-Application
.	O
</s>
<s>
In	O
the	O
Unix-world	O
,	O
there	O
is	O
commonly	O
a	O
special	O
filesystem	B-Application
mounted	O
at	O
/proc	B-Application
.	O
</s>
<s>
This	O
filesystem	B-Application
is	O
implemented	O
within	O
the	O
kernel	B-Operating_System
and	O
publishes	O
information	O
about	O
processes	O
.	O
</s>
<s>
For	O
each	O
process	B-Operating_System
,	O
there	O
is	O
a	O
directory	B-Application
(	O
named	O
by	O
the	O
process	B-Operating_System
ID	I-Operating_System
)	O
,	O
containing	O
detailed	O
information	O
about	O
the	O
process	B-Operating_System
:	O
status	B-Operating_System
,	O
open	O
files	O
,	O
memory	B-General_Concept
maps	I-General_Concept
,	O
mounts	O
,	O
etc	O
.	O
</s>
<s>
/proc	B-Application
first	O
appeared	O
in	O
Unix	B-Application
8th	O
Edition	O
,	O
and	O
its	O
functionality	O
was	O
greatly	O
expanded	O
in	O
Plan	B-Operating_System
9	I-Operating_System
from	I-Operating_System
Bell	I-Operating_System
Labs	I-Operating_System
.	O
</s>
<s>
The	O
/sys	O
filesystem	B-Application
on	O
Linux	O
complements	O
/proc	B-Application
,	O
by	O
providing	O
a	O
lot	O
of	O
(	O
non-process	O
related	O
)	O
detailed	O
information	O
about	O
the	O
in-kernel	O
status	B-Operating_System
to	O
userspace	O
.	O
</s>
<s>
More	O
traditional	B-Application
Unix	I-Application
systems	O
locate	O
this	O
information	O
in	O
sysctl	O
calls	O
.	O
</s>
<s>
ObexFS	O
is	O
a	O
FUSE-based	O
filesystem	B-Application
that	O
provides	O
access	O
to	O
OBEX	B-General_Concept
objects	O
via	O
a	O
filesystem	B-Application
.	O
</s>
<s>
Applications	O
can	O
work	O
on	O
remote	O
objects	O
via	O
the	O
OBEX	B-General_Concept
protocol	O
as	O
if	O
they	O
were	O
simply	O
(	O
local	O
)	O
files	O
.	O
</s>
<s>
On	O
the	O
Plan	B-Operating_System
9	I-Operating_System
from	I-Operating_System
Bell	I-Operating_System
Labs	I-Operating_System
operating	O
system	O
family	O
,	O
the	O
concept	O
of	O
9P	B-Operating_System
synthetic	B-Application
filesystem	I-Application
is	O
used	O
as	O
a	O
generic	O
IPC	B-Operating_System
method	O
.	O
</s>
<s>
Contrary	O
to	O
most	O
other	O
operating	O
systems	O
,	O
Plan	B-Operating_System
9	I-Operating_System
's	O
design	O
is	O
heavily	O
distributed	O
:	O
while	O
in	O
other	O
OS	O
worlds	O
,	O
there	O
are	O
many	O
(	O
and	O
often	O
large	O
)	O
libraries	O
and	O
frameworks	O
for	O
common	O
things	O
,	O
Plan	B-Operating_System
9	I-Operating_System
encapsulates	O
them	O
into	O
fileservers	O
.	O
</s>
<s>
Plan	B-Operating_System
9	I-Operating_System
drives	O
this	O
concept	O
expansively	O
:	O
most	O
operating	O
system	O
services	O
,	O
e.g.	O
</s>
<s>
Other	O
implementations	O
of	O
the	O
9P	B-Operating_System
file	B-Application
system	I-Application
protocol	O
also	O
exists	O
for	O
many	O
other	O
systems	O
and	O
environments	O
.	O
</s>
<s>
Based	O
on	O
9P	B-Operating_System
,	O
Plan	B-Operating_System
9	I-Operating_System
's	O
network	O
filesystem	B-Application
,	O
studies	O
suggest	O
using	O
synthetic	B-Application
filesystems	I-Application
as	O
universal	O
access	O
scheme	O
to	O
that	O
information	O
.	O
</s>
<s>
The	O
major	O
benefit	O
is	O
that	O
9P	B-Operating_System
is	O
very	O
simple	O
and	O
so	O
quite	O
easy	O
to	O
implement	O
in	O
hardware	O
and	O
can	O
be	O
easily	O
used	O
and	O
over	O
virtually	O
any	O
kind	O
of	O
network	O
(	O
from	O
a	O
serial	O
link	O
up	O
to	O
the	O
internet	O
)	O
.	O
</s>
<s>
The	O
major	O
argument	O
for	O
using	O
synthetic	B-Application
filesystems	I-Application
might	O
be	O
the	O
flexibility	O
and	O
easy	O
access	O
to	O
service-oriented	O
architectures	O
.	O
</s>
<s>
Arguments	O
against	O
synthetic	B-Application
filesystems	I-Application
include	O
the	O
fact	O
that	O
filesystem	B-Application
semantics	O
may	O
not	O
fit	O
all	O
application	O
scenarios	O
.	O
</s>
<s>
For	O
example	O
,	O
complex	O
remote	B-Operating_System
procedure	I-Operating_System
calls	I-Operating_System
with	O
many	O
parameters	O
tend	O
to	O
be	O
hard	O
to	O
map	O
to	O
filesystem	B-Application
schemes	O
,	O
and	O
may	O
require	O
application	O
redesign	O
.	O
</s>
