<s>
Munin	B-Protocol
is	O
a	O
free	B-License
and	I-License
open-source	I-License
computer	O
system	B-Application
monitoring	I-Application
,	O
network	O
monitoring	O
,	O
and	O
infrastructure	O
monitoring	O
software	B-Application
application	I-Application
.	O
</s>
<s>
Munin	B-Protocol
is	O
written	O
in	O
Perl	B-Language
and	O
uses	O
RRDtool	B-Language
to	O
create	O
graphs	O
,	O
which	O
are	O
accessible	O
over	O
a	O
web	B-Application
interface	I-Application
.	O
</s>
<s>
Its	O
emphasis	O
is	O
on	O
plug	B-Device
and	I-Device
play	I-Device
capabilities	O
.	O
</s>
<s>
About	O
500	O
monitoring	O
plugins	B-Application
are	O
currently	O
available	O
.	O
</s>
<s>
Munin	B-Protocol
was	O
started	O
by	O
Jimmy	O
Olsen	O
late	O
2003	O
,	O
based	O
on	O
RRDtool	B-Language
by	O
Tobi	O
Oetiker	O
.	O
</s>
<s>
Development	O
has	O
slowed	O
since	O
2005	O
,	O
but	O
Munin	B-Protocol
is	O
a	O
stable	O
tool	O
and	O
is	O
still	O
maintained	O
.	O
</s>
<s>
One	O
of	O
the	O
two	O
ravens	O
who	O
report	O
the	O
news	O
of	O
the	O
world	O
to	O
the	O
god	O
Odin	O
is	O
called	O
Munin	B-Protocol
,	O
and	O
the	O
other	O
is	O
named	O
Hugin	O
.	O
</s>
<s>
Plugins	B-Application
are	O
the	O
specialized	O
programs	O
that	O
are	O
called	O
by	O
Munin	B-Protocol
nodes	O
to	O
gather	O
and	O
report	O
current	O
data	O
,	O
and	O
describe	O
how	O
it	O
should	O
be	O
presented	O
.	O
</s>
<s>
There	O
are	O
over	O
300	O
plugins	B-Application
in	O
the	O
core	O
distribution	O
,	O
over	O
180	O
plugins	B-Application
in	O
the	O
official	O
third-party	O
contributed	O
repository	O
,	O
and	O
an	O
unknown	O
number	O
of	O
independently	O
published	O
plugins	B-Application
.	O
</s>
<s>
All	O
they	O
are	O
required	O
to	O
do	O
is	O
print	O
space	O
separated	O
key	O
and	O
value	O
pairs	O
on	O
standard	B-Operating_System
output	I-Operating_System
.	O
</s>
<s>
This	O
framework	O
makes	O
it	O
trivial	O
to	O
write	O
customized	O
plugins	B-Application
.	O
</s>
