<s>
Desktop	B-Device
sharing	I-Device
is	O
a	O
common	O
name	O
for	O
technologies	O
and	O
products	O
that	O
allow	O
remote	O
access	O
and	O
remote	O
collaboration	O
on	O
a	O
person	O
's	O
computer	O
desktop	B-Device
through	O
a	O
graphical	O
terminal	B-Application
emulator	I-Application
.	O
</s>
<s>
The	O
most	O
common	O
two	O
scenarios	O
for	O
desktop	B-Device
sharing	I-Device
are	O
:	O
</s>
<s>
Remote	O
log-in	O
allows	O
users	O
to	O
connect	O
to	O
their	O
own	O
desktop	B-Device
while	O
being	O
physically	O
away	O
from	O
their	O
computer	O
.	O
</s>
<s>
Systems	O
that	O
support	O
the	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
,	O
typically	O
Unix-based	O
ones	O
,	O
have	O
this	O
ability	O
"	O
built	O
in	O
"	O
.	O
</s>
<s>
Windows	O
versions	O
starting	O
from	O
Windows	O
2000	O
have	O
a	O
built-in	O
solution	O
for	O
remote	O
access	O
as	O
well	O
in	O
the	O
form	O
of	O
Remote	B-Protocol
Desktop	I-Protocol
Protocol	I-Protocol
and	O
prior	O
to	O
that	O
in	O
the	O
form	O
of	O
Microsoft	O
’s	O
NetMeeting	B-Protocol
.	O
</s>
<s>
Virtual	B-Protocol
Network	I-Protocol
Computing	I-Protocol
(	O
VNC	B-Protocol
)	O
is	O
a	O
cross-platform	O
solution	O
accomplished	O
through	O
a	O
common	O
client/server	O
model	O
.	O
</s>
<s>
The	O
client	O
,	O
or	O
VNC	B-Protocol
viewer	O
,	O
is	O
installed	O
on	O
a	O
local	O
computer	O
and	O
then	O
connects	O
to	O
the	O
network	O
via	O
a	O
server	O
component	O
,	O
which	O
is	O
installed	O
on	O
a	O
remote	B-Protocol
computer	I-Protocol
.	O
</s>
<s>
In	O
a	O
typical	O
VNC	B-Protocol
session	O
,	O
all	O
keystrokes	O
and	O
mouse	O
clicks	O
are	O
registered	O
as	O
if	O
the	O
client	O
were	O
actually	O
performing	O
tasks	O
on	O
the	O
end-user	O
machine	O
.	O
</s>
<s>
The	O
shortcoming	O
of	O
the	O
above	O
solutions	O
are	O
their	O
inability	O
to	O
work	O
outside	O
of	O
a	O
single	O
NAT	B-Protocol
environment	O
.	O
</s>
<s>
A	O
number	O
of	O
commercial	O
products	O
overcome	O
this	O
restriction	O
by	O
tunneling	B-Protocol
the	O
traffic	O
through	O
rendezvous	O
servers	O
.	O
</s>
<s>
Apple	O
machines	O
require	O
Apple	B-Operating_System
Remote	I-Operating_System
Desktop	I-Operating_System
(	O
ARD	O
)	O
.	O
</s>
<s>
Real-time	B-Application
collaboration	I-Application
is	O
a	O
bigger	O
area	O
of	O
desktop	B-Device
sharing	I-Device
use	O
and	O
has	O
gained	O
momentum	O
as	O
an	O
important	O
component	O
of	O
rich	O
multimedia	O
communications	O
.	O
</s>
<s>
Desktop	B-Device
sharing	I-Device
,	O
when	O
used	O
in	O
conjunction	O
with	O
other	O
components	O
of	O
multimedia	O
communications	O
such	O
as	O
audio	O
and	O
video	O
,	O
offers	O
people	O
to	O
meet	O
and	O
work	O
together	O
.	O
</s>
<s>
On	O
the	O
larger	O
scale	O
,	O
this	O
area	O
is	O
also	O
referred	O
as	O
web	B-Protocol
conferencing	I-Protocol
.	O
</s>
<s>
With	O
a	O
larger	O
number	O
of	O
applications	O
moving	O
from	O
desktop	B-Device
machines	O
to	O
cloud	B-Architecture
computing	I-Architecture
,	O
newer	O
forms	O
of	O
browser	O
based	O
instant	O
screen	O
sharing	O
have	O
developed	O
such	O
as	O
Cobrowsing	B-Protocol
.	O
</s>
