<s>
FireHOL	B-Protocol
is	O
a	O
shell	B-Language
script	I-Language
designed	O
as	O
a	O
wrapper	O
for	O
iptables	B-Application
written	O
to	O
ease	O
the	O
customization	O
of	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
's	O
firewall	B-Application
netfilter	B-Application
.	O
</s>
<s>
FireHOL	B-Protocol
is	O
free	B-License
software	I-License
and	I-License
open-source	I-License
,	O
distributed	O
under	O
the	O
terms	O
of	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
.	O
</s>
<s>
FireHOL	B-Protocol
does	O
not	O
have	O
graphical	B-Application
user	I-Application
interface	I-Application
,	O
but	O
is	O
configured	O
through	O
an	O
easy	O
to	O
understand	O
plain	O
text	O
configuration	O
file	O
.	O
</s>
<s>
FireHOL	B-Protocol
first	O
parses	O
the	O
configuration	O
file	O
and	O
then	O
sets	O
the	O
appropriate	O
iptables	B-Application
rules	O
to	O
achieve	O
the	O
expected	O
firewall	B-Application
behavior	O
.	O
</s>
<s>
It	O
is	O
a	O
large	O
,	O
complex	O
BASH	B-Operating_System
script	I-Operating_System
file	O
,	O
depending	O
on	O
the	O
iptables	B-Application
console	O
tools	O
rather	O
than	O
communicating	O
with	O
the	O
kernel	B-Operating_System
directly	O
.	O
</s>
<s>
Any	O
Linux	B-Operating_System
system	O
with	O
iptables	B-Application
,	O
BASH	B-Operating_System
,	O
and	O
the	O
appropriate	O
tools	O
can	O
run	O
it	O
.	O
</s>
<s>
FireHOL	B-Protocol
's	O
configuration	O
files	O
are	O
fully	O
functional	O
BASH	B-Operating_System
scripts	I-Operating_System
in	O
of	O
themselves	O
.	O
</s>
