<s>
OSCAR	O
(	O
Open	O
System	O
for	O
CommunicAtion	O
in	O
Realtime	O
)	O
is	O
AOL	O
's	O
proprietary	O
instant	B-Application
messaging	I-Application
and	O
presence	B-Protocol
information	I-Protocol
protocol	O
.	O
</s>
<s>
It	O
was	O
used	O
by	O
AOL	O
's	O
AIM	B-Protocol
instant	B-Application
messaging	I-Application
system	O
and	O
ICQ	B-Protocol
.	O
</s>
<s>
AOL	O
has	O
gone	O
to	O
great	O
lengths	O
to	O
keep	O
competitors	O
(	O
namely	O
Microsoft	O
,	O
XMPP	B-Protocol
,	O
and	O
Cerulean	O
Studios	O
)	O
from	O
implementing	O
compatible	O
clients	O
for	O
their	O
proprietary	O
messaging	O
systems	O
.	O
</s>
<s>
In	O
2002	O
,	O
AOL	O
signed	O
a	O
contract	O
with	O
Apple	O
,	O
Inc.	O
,	O
allowing	O
them	O
to	O
use	O
OSCAR	O
(	O
as	O
well	O
as	O
AOL	O
's	O
own	O
code	O
libraries	O
)	O
in	O
their	O
iChat	B-Protocol
application	O
.	O
</s>
<s>
This	O
allowed	O
iChat	B-Protocol
users	O
to	O
interact	O
with	O
ICQ	B-Protocol
and	O
AIM	B-Protocol
users	O
directly	O
.	O
</s>
<s>
The	O
deal	O
also	O
permitted	O
users	O
of	O
Apple	O
's	O
.Mac	B-Application
service	O
to	O
log	B-General_Concept
in	I-General_Concept
to	O
the	O
AIM	B-Protocol
network	O
using	O
their	O
.Mac	B-Application
email	O
addresses	O
.	O
</s>
<s>
(	O
This	O
has	O
carried	O
over	O
to	O
Apple	O
's	O
MobileMe	B-Application
service	O
.	O
)	O
</s>
<s>
The	O
OSCAR	B-Application
protocol	I-Application
can	O
be	O
used	O
separately	O
from	O
AOL	O
's	O
network	O
.	O
</s>
<s>
In	O
fact	O
,	O
AOL	O
expands	O
on	O
the	O
general	O
concept	O
of	O
OSCAR	O
,	O
adding	O
systems	O
for	O
service-side	O
buddy	O
lists	O
and	O
icons	O
,	O
as	O
well	O
as	O
features	O
for	O
file	O
transfers	O
using	O
Bonjour	B-Application
.	O
</s>
<s>
On	O
March	O
6	O
,	O
2006	O
,	O
AOL	O
released	O
the	O
AIM	B-Protocol
SDK	B-Application
and	O
launched	O
a	O
developer	O
website	O
,	O
allowing	O
developers	O
to	O
build	O
plugins	O
for	O
AIM	B-Protocol
Triton	I-Protocol
,	O
and	O
build	O
their	O
own	O
custom	O
clients	O
,	O
which	O
connect	O
over	O
the	O
OSCAR	B-Application
protocol	I-Application
.	O
</s>
<s>
On	O
March	O
5	O
,	O
2008	O
,	O
AOL	O
released	O
portions	O
of	O
the	O
OSCAR	B-Application
protocol	I-Application
documentation	O
.	O
</s>
<s>
Google	O
also	O
provided	O
the	O
ability	O
to	O
sign	O
in	O
to	O
AIM	B-Protocol
network	O
via	O
the	O
Google	B-Application
Talk	I-Application
client	O
built	O
into	O
Gmail	B-Application
.	O
</s>
<s>
It	O
is	O
mark	O
of	O
packet	O
start.01Channelbyte/11	O
=	O
login	B-General_Concept
,	O
2	O
=	O
SNAC	O
layer	O
,	O
3	O
=	O
error	O
,	O
4	O
=	O
disconnect02Number	O
in	O
sequenceint16/2Incremented	O
by	O
1	O
each	O
time	O
a	O
packet	O
sent	O
.	O
</s>
