<s>
Independent	B-Protocol
Computing	I-Protocol
Architecture	I-Protocol
(	O
ICA	O
)	O
is	O
a	O
proprietary	O
protocol	O
for	O
an	O
application	B-Application
server	I-Application
system	O
,	O
designed	O
by	O
Citrix	B-Application
Systems	I-Application
.	O
</s>
<s>
Citrix	B-Application
's	O
ICA	O
is	O
an	O
alternative	O
to	O
Microsoft	O
's	O
Remote	B-Protocol
Desktop	I-Protocol
Protocol	I-Protocol
(	O
RDP	O
)	O
.	O
</s>
<s>
Practical	O
products	O
conforming	O
to	O
ICA	O
are	O
Citrix	B-Application
's	O
WinFrame	O
,	O
Citrix	B-General_Concept
XenApp	I-General_Concept
(	O
formerly	O
called	O
MetaFrame/Presentation	O
Server	O
)	O
,	O
and	O
Citrix	B-General_Concept
XenDesktop	I-General_Concept
products	O
.	O
</s>
<s>
These	O
permit	O
ordinary	O
Windows	B-Application
applications	I-Application
to	O
be	O
run	O
on	O
a	O
suitable	O
Windows	B-Application
server	O
,	O
and	O
for	O
any	O
supported	O
client	O
to	O
gain	O
access	O
to	O
those	O
applications	O
.	O
</s>
<s>
Besides	O
Windows	B-Application
,	O
ICA	O
is	O
also	O
supported	O
on	O
a	O
number	O
of	O
Unix	B-Application
server	O
platforms	O
and	O
can	O
be	O
used	O
to	O
deliver	O
access	O
to	O
applications	O
running	O
on	O
these	O
platforms	O
.	O
</s>
<s>
The	O
client	O
platforms	O
need	O
not	O
run	O
Windows	B-Application
;	O
for	O
example	O
,	O
there	O
are	O
clients	O
for	O
Mac	B-Device
,	O
Unix	B-Application
,	O
Linux	B-Application
,	O
and	O
various	O
smartphones	O
.	O
</s>
<s>
ICA	O
client	O
software	O
is	O
also	O
built	O
into	O
various	O
thin	B-Device
client	I-Device
platforms	O
.	O
</s>
<s>
ICA	O
is	O
broadly	O
similar	O
in	O
purpose	O
to	O
window	O
servers	O
such	O
as	O
the	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
.	O
</s>
<s>
There	O
are	O
Key	O
challenges	O
in	O
an	O
architecture	O
are	O
network	B-Protocol
latency	I-Protocol
and	O
performance	O
—	O
a	O
graphically	O
intensive	O
application	O
(	O
as	O
most	O
are	O
when	O
presented	O
using	O
a	O
GUI	B-Application
)	O
being	O
served	O
over	O
a	O
slow	O
or	O
bandwidth-restricted	O
network	O
connection	O
requires	O
considerable	O
compression	O
and	O
optimization	O
to	O
render	O
the	O
application	O
usable	O
by	O
the	O
client	O
.	O
</s>
<s>
The	O
client	O
machine	O
may	O
be	O
a	O
different	O
platform	O
,	O
and	O
may	O
not	O
have	O
the	O
same	O
GUI	B-Application
routines	O
available	O
locally	O
—	O
in	O
this	O
case	O
the	O
server	O
may	O
need	O
to	O
send	O
the	O
actual	O
bitmap	O
data	O
over	O
the	O
connection	O
.	O
</s>
<s>
ICA	O
supports	O
the	O
concept	O
of	O
channels	O
at	O
a	O
session	B-Application
layer	I-Application
to	O
encapsulate	O
rich	O
media	O
redirection	O
or	O
USB	O
extension	O
within	O
ICA	O
.	O
</s>
