<s>
In	O
storage	O
area	O
networking	O
,	O
Fabric	B-Protocol
OS	I-Protocol
is	O
the	O
firmware	B-Application
for	O
Brocade	O
Communications	O
Systems	O
's	O
Fibre	B-Architecture
Channel	I-Architecture
switches	I-Architecture
and	O
Fibre	B-Architecture
Channel	I-Architecture
directors	I-Architecture
.	O
</s>
<s>
The	O
first	O
generation	O
of	O
Fabric	B-Protocol
OS	I-Protocol
was	O
developed	O
on	O
top	O
of	O
a	O
VxWorks	B-Operating_System
kernel	B-Operating_System
and	O
was	O
mainly	O
used	O
in	O
the	O
Brocade	O
Silkworm	O
2000	O
and	O
first	O
3000	O
series	O
on	O
Intel	B-General_Concept
i960	I-General_Concept
.	O
</s>
<s>
The	O
second	O
generation	O
of	O
Fabric	B-Protocol
OS	I-Protocol
was	O
developed	O
on	O
a	O
PowerPC	B-Architecture
platform	I-Architecture
,	O
and	O
uses	O
MontaVista	B-Operating_System
Linux	I-Operating_System
,	O
a	O
Linux	B-Application
derivative	O
with	O
real-time	B-General_Concept
performance	O
enhancements	O
.	O
</s>
<s>
With	O
the	O
advent	O
of	O
MontaVista	B-Operating_System
,	O
switches	O
and	O
directors	O
have	O
the	O
ability	O
of	O
hot	O
firmware	B-Application
activation	O
(	O
without	O
downtime	O
for	O
Fibre	B-Architecture
Channel	I-Architecture
fabric	I-Architecture
)	O
,	O
and	O
many	O
useful	O
diagnostic	O
commands	O
.	O
</s>
<s>
According	O
to	O
free	O
software	O
licenses	O
terms	O
,	O
Brocade	O
of	O
distributed	O
free	O
software	O
,	O
on	O
which	O
Fabric	B-Protocol
OS	I-Protocol
and	O
other	O
Brocade	O
's	O
software	O
products	O
are	O
based	O
.	O
</s>
<s>
Additional	O
products	O
for	O
Fabric	B-Protocol
OS	I-Protocol
are	O
offered	O
by	O
Brocade	O
for	O
one-time	O
fee	O
.	O
</s>
