<s>
A	O
LAN	B-Protocol
Messenger	I-Protocol
is	O
an	O
instant	B-Application
messaging	I-Application
program	O
for	O
computers	O
designed	O
for	O
use	O
within	O
a	O
single	O
local	B-General_Concept
area	I-General_Concept
network	I-General_Concept
(	O
LAN	B-General_Concept
)	O
.	O
</s>
<s>
Many	O
LAN	B-Protocol
Messengers	I-Protocol
offer	O
basics	O
functionality	O
for	O
sending	O
private	O
messages	O
,	O
file	B-Protocol
transfer	I-Protocol
,	O
chatrooms	O
and	O
graphical	O
smileys	O
.	O
</s>
<s>
The	O
advantage	O
of	O
using	O
a	O
simple	O
LAN	B-Protocol
messenger	I-Protocol
over	O
a	O
normal	O
instant	B-Application
messenger	I-Application
is	O
that	O
no	O
active	O
Internet	O
connection	O
or	O
central	B-Application
server	I-Application
is	O
required	O
,	O
and	O
only	O
people	O
inside	O
the	O
firewall	B-Application
will	O
have	O
access	O
to	O
the	O
system	O
.	O
</s>
<s>
A	O
precursor	O
of	O
LAN	B-Protocol
Messengers	I-Protocol
is	O
the	O
Unix	B-Device
talk	I-Device
command	O
,	O
and	O
similar	O
facilities	O
on	O
earlier	O
systems	O
,	O
which	O
enabled	O
multiple	O
users	O
on	O
one	O
host	O
system	O
to	O
directly	O
talk	B-Device
with	O
each	O
other	O
.	O
</s>
<s>
Novell	B-Operating_System
NetWare	I-Operating_System
featured	O
a	O
trivial	O
person-to-person	O
chat	O
program	O
for	O
DOS	O
,	O
which	O
used	O
the	O
 [ IPX/SPX ] 	O
protocol	O
suite	O
.	O
</s>
<s>
NetWare	B-Operating_System
for	O
Windows	B-Application
also	O
included	O
broadcast	O
and	O
targeted	O
messages	O
similar	O
to	O
WinPopup	B-Protocol
and	O
the	O
Windows	B-Protocol
Messenger	I-Protocol
service	I-Protocol
.	O
</s>
<s>
On	O
Windows	B-Application
,	O
WinPopup	B-Protocol
was	O
a	O
small	O
utility	O
included	O
with	O
Windows	B-Application
3.11	O
.	O
</s>
<s>
WinPopup	B-Protocol
uses	O
SMB/NetBIOS	O
protocol	O
and	O
was	O
intended	O
to	O
receive	O
and	O
send	O
short	O
text	O
messages	O
.	O
</s>
<s>
Windows	B-Application
NT/2000/XP	O
improves	O
upon	O
this	O
with	O
Windows	B-Protocol
Messenger	I-Protocol
service	I-Protocol
,	O
a	O
Windows	B-Application
service	O
compatible	O
to	O
WinPopup	B-Protocol
.	O
</s>
<s>
Any	O
software	O
compatible	O
with	O
WinPopup	B-Protocol
,	O
like	O
the	O
console	O
utility	O
NET	B-Protocol
SEND	I-Protocol
,	O
can	O
send	O
such	O
messages	O
.	O
</s>
<s>
However	O
,	O
due	O
to	O
security	O
concerns	O
,	O
by	O
default	O
,	O
the	O
messenger	B-Protocol
service	O
is	O
off	O
in	O
Windows	B-Application
XP	O
SP2	O
and	O
blocked	O
by	O
Windows	B-Application
XP	O
's	O
firewall	B-Application
.	O
</s>
<s>
On	O
Apple	O
's	O
-based	O
computers	O
,	O
the	O
iChat	B-Protocol
program	O
has	O
allowed	O
LAN	B-General_Concept
messaging	O
over	O
the	O
Bonjour	B-Application
protocol	I-Application
since	O
2005	O
.	O
</s>
<s>
The	O
multi-protocol	O
messenger	B-Protocol
Pidgin	B-Protocol
has	O
support	O
for	O
the	O
Bonjour	B-Application
protocol	I-Application
,	O
including	O
on	O
Windows	B-Application
.	O
</s>
