<s>
In	O
computing	O
,	O
the	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
(	O
commonly	O
:	O
X11	B-Operating_System
,	O
or	O
X	B-Operating_System
)	O
is	O
a	O
network-transparent	B-General_Concept
windowing	B-Application
system	I-Application
for	O
bitmap	B-Algorithm
displays	O
.	O
</s>
<s>
This	O
article	O
details	O
the	O
protocols	O
and	O
technical	O
structure	O
of	O
X11	B-Operating_System
.	O
</s>
<s>
X	B-Operating_System
uses	O
a	O
client	B-Operating_System
–	I-Operating_System
server	I-Operating_System
model	I-Operating_System
.	O
</s>
<s>
An	O
X	B-Operating_System
server	O
program	O
runs	O
on	O
a	O
computer	O
with	O
a	O
graphical	O
display	O
and	O
communicates	O
with	O
various	O
client	O
programs	O
.	O
</s>
<s>
The	O
X	B-Operating_System
server	O
acts	O
as	O
a	O
go-between	O
for	O
the	O
user	O
and	O
the	O
client	O
programs	O
,	O
accepting	O
requests	O
on	O
TCP	O
port	O
6000	O
for	O
graphical	O
output	O
(	O
windows	O
)	O
from	O
the	O
client	O
programs	O
and	O
displaying	O
them	O
to	O
the	O
user	O
(	O
display	O
)	O
,	O
and	O
receiving	O
user	O
input	O
(	O
keyboard	O
,	O
mouse	O
)	O
and	O
transmitting	O
it	O
to	O
the	O
client	O
programs	O
.	O
</s>
<s>
In	O
X	B-Operating_System
,	O
the	O
server	O
runs	O
on	O
the	O
user	O
's	O
computer	O
,	O
while	O
the	O
clients	O
may	O
run	O
on	O
remote	O
machines	O
.	O
</s>
<s>
This	O
terminology	O
reverses	O
the	O
common	O
notion	O
of	O
client	B-Operating_System
–	I-Operating_System
server	I-Operating_System
systems	O
,	O
where	O
the	O
client	O
normally	O
runs	O
on	O
the	O
user	O
's	O
local	O
computer	O
and	O
the	O
server	O
runs	O
on	O
the	O
remote	O
computer	O
.	O
</s>
<s>
The	O
X	B-Operating_System
Window	I-Operating_System
terminology	O
takes	O
the	O
perspective	O
that	O
the	O
X	B-Operating_System
Window	I-Operating_System
program	O
is	O
at	O
the	O
centre	O
of	O
all	O
activity	O
,	O
i.e.	O
</s>
<s>
the	O
X	B-Operating_System
Window	I-Operating_System
program	O
accepts	O
and	O
responds	O
to	O
requests	O
from	O
applications	O
,	O
and	O
from	O
the	O
user	O
's	O
mouse	O
and	O
keyboard	O
input	O
.	O
</s>
<s>
Therefore	O
,	O
applications	O
(	O
on	O
remote	O
computers	O
)	O
are	O
viewed	O
as	O
clients	O
of	O
the	O
X	B-Operating_System
Window	I-Operating_System
server	O
program	O
.	O
</s>
<s>
The	O
communication	O
protocol	O
between	O
server	O
and	O
client	O
runs	O
network-transparently	B-General_Concept
:	O
the	O
client	O
and	O
server	O
may	O
run	O
on	O
the	O
same	O
machine	O
or	O
on	O
different	O
ones	O
,	O
possibly	O
with	O
different	O
architectures	B-General_Concept
and	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
A	O
client	O
and	O
server	O
can	O
communicate	O
securely	O
over	O
the	O
Internet	O
by	O
tunneling	B-Protocol
the	O
connection	O
over	O
an	O
encrypted	O
connection	O
.	O
</s>
<s>
Bob	O
Scheifler	O
and	O
Jim	O
Gettys	O
set	O
out	O
the	O
early	O
principles	O
of	O
X	B-Operating_System
as	O
follows	O
(	O
as	O
listed	O
in	O
Scheifler/Gettys	O
1996	O
)	O
:	O
</s>
<s>
The	O
first	O
principle	O
was	O
modified	O
during	O
the	O
design	O
of	O
X11	B-Operating_System
to	O
:	O
Do	O
not	O
add	O
new	O
functionality	O
unless	O
you	O
know	O
of	O
some	O
real	O
application	O
that	O
will	O
require	O
it	O
.	O
</s>
<s>
X	B-Operating_System
has	O
largely	O
kept	O
to	O
these	O
principles	O
since	O
.	O
</s>
<s>
The	O
X.Org	B-Application
Foundation	I-Application
develops	O
the	O
reference	B-Operating_System
implementation	I-Operating_System
with	O
a	O
view	O
to	O
extension	O
and	O
improvement	O
of	O
the	O
implementation	O
,	O
whilst	O
keeping	O
it	O
almost	O
entirely	O
compatible	O
with	O
the	O
original	O
1987	O
protocol	O
.	O
</s>
<s>
Event	O
:	O
the	O
server	O
sends	O
an	O
event	O
to	O
the	O
client	O
,	O
e.g.	O
,	O
keyboard	O
or	O
mouse	O
input	O
,	O
or	O
a	O
window	O
being	O
moved	O
,	O
resized	O
or	O
exposed	O
.	O
</s>
<s>
The	O
X	B-Operating_System
server	O
provides	O
a	O
set	O
of	O
basic	O
services	O
.	O
</s>
<s>
What	O
other	O
graphical	B-Application
user	I-Application
interfaces	I-Application
usually	O
call	O
a	O
window	O
is	O
a	O
top-level	O
window	O
in	O
the	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
.	O
</s>
<s>
The	O
X	B-Operating_System
server	O
automatically	O
creates	O
the	O
root	O
of	O
the	O
tree	O
,	O
called	O
the	O
root	B-Device
window	I-Device
.	O
</s>
<s>
The	O
top-level	O
windows	O
are	O
exactly	O
the	O
direct	O
subwindows	O
of	O
the	O
root	B-Device
window	I-Device
.	O
</s>
<s>
Visibly	O
,	O
the	O
root	B-Device
window	I-Device
is	O
as	O
large	O
as	O
the	O
screen	O
,	O
and	O
lies	O
behind	O
all	O
other	O
windows	O
.	O
</s>
<s>
The	O
X	B-Operating_System
server	O
stores	O
all	O
data	O
about	O
windows	O
,	O
fonts	O
,	O
etc	O
.	O
</s>
<s>
Every	O
window	O
has	O
a	O
predefined	O
set	O
of	O
attributes	O
and	O
a	O
set	O
of	O
properties	O
,	O
all	O
stored	O
in	O
the	O
X	B-Operating_System
server	O
and	O
accessible	O
to	O
the	O
clients	O
via	O
appropriate	O
requests	O
.	O
</s>
<s>
Unlike	O
attributes	O
,	O
properties	O
have	O
no	O
meaning	O
at	O
the	O
level	O
of	O
the	O
X	B-Device
Window	I-Device
core	I-Device
protocol	I-Device
.	O
</s>
<s>
Properties	O
resemble	O
variables	O
in	O
imperative	B-Application
programming	I-Application
languages	I-Application
,	O
in	O
that	O
the	O
application	O
can	O
create	O
a	O
new	O
property	O
with	O
a	O
given	O
name	O
and	O
of	O
a	O
given	O
type	O
and	O
store	O
a	O
value	O
in	O
it	O
.	O
</s>
<s>
In	O
particular	O
,	O
xprop	O
-root	O
shows	O
the	O
properties	O
of	O
the	O
root	B-Device
window	I-Device
,	O
which	O
include	O
the	O
X	B-Device
resources	I-Device
(	O
parameters	O
of	O
programs	O
)	O
.	O
</s>
<s>
The	O
way	O
the	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
handles	O
colors	O
can	O
sometimes	O
confuse	O
users	O
,	O
and	O
historically	O
several	O
different	O
modes	O
have	O
been	O
supported	O
.	O
</s>
<s>
The	O
X11	B-Operating_System
protocol	O
actually	O
uses	O
a	O
single	O
32-bit	O
unsigned	O
integer	O
-	O
called	O
a	O
pixelvalue	O
-	O
for	O
representing	O
a	O
single	O
color	O
in	O
most	O
graphic	O
operations	O
.	O
</s>
<s>
PseudoColor	O
(	O
Chunky	B-General_Concept
)	O
:	O
A	O
pixel	O
value	O
indexes	O
a	O
single	O
colormap	O
that	O
contains	O
color	O
intensities	O
.	O
</s>
<s>
Most	O
client	O
programs	O
communicate	O
with	O
the	O
server	O
via	O
the	O
Xlib	B-Language
client	O
library	O
.	O
</s>
<s>
Beside	O
Xlib	B-Language
,	O
the	O
XCB	B-Language
library	O
operates	O
more	O
closely	O
to	O
X	B-Device
protocol	I-Device
.	O
</s>
<s>
In	O
particular	O
,	O
most	O
clients	O
use	O
libraries	O
such	O
as	O
Xaw	B-Library
,	O
Motif	B-Application
,	O
GTK+	B-Application
,	O
or	O
Qt	B-Language
which	O
in	O
turn	O
use	O
Xlib	B-Language
for	O
interacting	O
with	O
the	O
server	O
.	O
</s>
<s>
Qt	B-Language
switched	O
from	O
Xlib	B-Language
to	O
XCB	B-Language
with	O
the	O
5.0	O
release	O
,	O
but	O
client	O
programs	O
were	O
almost	O
entirely	O
unaffected	O
by	O
this	O
change	O
.	O
</s>
<s>
The	O
X	B-Device
Window	I-Device
core	I-Device
protocol	I-Device
provides	O
mechanisms	O
for	O
communication	O
between	O
clients	O
:	O
window	B-Device
properties	I-Device
and	O
events	O
,	O
in	O
particular	O
the	O
client-to-client	O
message	O
events	O
.	O
</s>
<s>
The	O
Inter-Client	B-Operating_System
Communication	I-Operating_System
Conventions	I-Operating_System
Manual	I-Operating_System
specifies	O
the	O
protocol	O
for	O
the	O
exchange	O
of	O
data	O
via	O
selections	O
and	O
the	O
interaction	O
of	O
applications	O
with	O
the	O
window	O
manager	O
.	O
</s>
<s>
Some	O
have	O
considered	O
this	O
specification	O
difficult	O
and	O
confusing	O
;	O
consistency	O
of	O
application	O
look	B-Application
and	I-Application
feel	I-Application
and	O
communication	O
is	O
typically	O
addressed	O
by	O
programming	O
to	O
a	O
given	O
desktop	O
environment	O
.	O
</s>
<s>
In	O
particular	O
,	O
the	O
X	B-Operating_System
Session	B-Protocol
Management	I-Protocol
protocol	O
(	O
XSMP	O
)	O
is	O
a	O
protocol	O
based	O
on	O
ICE	O
that	O
governs	O
the	O
interaction	O
between	O
applications	O
with	O
the	O
session	B-Protocol
manager	I-Protocol
,	O
which	O
is	O
the	O
program	O
that	O
takes	O
care	O
of	O
storing	O
the	O
status	O
of	O
the	O
desktop	O
at	O
the	O
end	O
of	O
an	O
interactive	O
session	B-Protocol
and	O
recovering	O
it	O
when	O
another	O
session	B-Protocol
with	O
the	O
same	O
user	O
is	O
started	O
again	O
.	O
</s>
<s>
The	O
freedesktop	B-Application
specifications	O
include	O
newer	O
conventions	O
,	O
including	O
the	O
drag-and-drop	O
convention	O
Xdnd	O
(	O
used	O
for	O
transferring	O
data	O
by	O
selecting	O
it	O
and	O
dragging	O
in	O
another	O
window	O
)	O
and	O
the	O
embedded	O
application	O
convention	O
Xembed	O
(	O
which	O
details	O
how	O
an	O
application	O
can	O
run	O
in	O
a	O
subwindow	O
of	O
another	O
application	O
)	O
.	O
</s>
<s>
The	O
mechanisms	O
of	O
selections	O
,	O
cut	O
buffers	O
,	O
and	O
drag-and-drop	O
in	O
the	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
allow	O
a	O
user	O
to	O
transfer	O
data	O
from	O
one	O
window	O
to	O
another	O
.	O
</s>
<s>
Since	O
two	O
different	O
applications	O
may	O
handle	O
the	O
two	O
windows	O
,	O
data	O
transfer	O
requires	O
different	O
clients	O
connected	O
with	O
the	O
same	O
X	B-Operating_System
server	O
to	O
interact	O
.	O
</s>
<s>
The	O
X	B-Device
Window	I-Device
core	I-Device
protocol	I-Device
includes	O
some	O
types	O
of	O
requests	O
and	O
events	O
that	O
are	O
specific	O
to	O
selection	O
exchange	O
,	O
but	O
the	O
transfer	O
is	O
mainly	O
done	O
using	O
the	O
general	O
client-to-client	O
event	O
sending	O
and	O
window	B-Device
properties	I-Device
,	O
which	O
are	O
not	O
specific	O
to	O
selection	O
transfer	O
.	O
</s>
<s>
A	O
window	O
manager	O
is	O
a	O
program	O
that	O
controls	O
the	O
general	O
appearance	O
of	O
windows	O
and	O
other	O
graphical	O
elements	O
of	O
the	O
graphical	B-Application
user	I-Application
interface	I-Application
.	O
</s>
<s>
Differences	O
in	O
the	O
look	O
of	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
in	O
different	O
installations	O
stem	O
mainly	O
from	O
the	O
use	O
of	O
different	O
window	O
managers	O
or	O
from	O
different	O
configurations	O
of	O
the	O
window	O
manager	O
.	O
</s>
<s>
From	O
the	O
point	O
of	O
view	O
of	O
the	O
X	B-Operating_System
server	O
,	O
the	O
window	O
manager	O
operates	O
as	O
a	O
client	O
just	O
like	O
any	O
other	O
client	O
.	O
</s>
<s>
The	O
window	O
manager	O
uses	O
the	O
first	O
request	O
to	O
intercept	O
any	O
request	O
for	O
mapping	O
top-level	O
windows	O
(	O
children	O
of	O
the	O
root	B-Device
window	I-Device
)	O
.	O
</s>
<s>
Most	O
window	O
managers	O
reparent	B-Device
the	O
window	O
:	O
they	O
create	O
a	O
larger	O
top-level	O
window	O
(	O
called	O
the	O
frame	O
window	O
)	O
and	O
reparent	B-Device
the	O
original	O
window	O
as	O
a	O
child	O
of	O
it	O
.	O
</s>
<s>
The	O
window	O
manager	O
also	O
handles	O
icons	O
and	O
related	O
visual	O
elements	O
of	O
the	O
graphical	B-Application
user	I-Application
interface	I-Application
.	O
</s>
<s>
Icons	O
do	O
not	O
exist	O
at	O
the	O
level	O
of	O
the	O
X	B-Device
Window	I-Device
core	I-Device
protocol	I-Device
.	O
</s>
<s>
For	O
example	O
,	O
whenever	O
a	O
window	O
has	O
to	O
be	O
“	O
iconified	O
”	O
,	O
the	O
FVWM	B-Device
window	O
manager	O
unmaps	O
the	O
window	O
,	O
and	O
creates	O
a	O
window	O
for	O
the	O
icon	O
name	O
and	O
possibly	O
another	O
window	O
for	O
the	O
icon	O
image	O
.	O
</s>
<s>
The	O
meaning	O
and	O
handling	O
of	O
icons	O
is	O
therefore	O
completely	O
decided	O
by	O
the	O
window	O
manager	O
:	O
some	O
window	O
managers	O
such	O
as	O
wm2	B-Device
do	O
not	O
implement	O
icons	O
at	O
all	O
.	O
</s>
<s>
Roughly	O
,	O
the	O
state	O
of	O
a	O
session	B-Protocol
is	O
the	O
“	O
state	O
of	O
the	O
desktop	O
”	O
at	O
a	O
given	O
time	O
:	O
a	O
set	O
of	O
windows	O
with	O
their	O
current	O
content	O
.	O
</s>
<s>
A	O
program	O
known	O
as	O
the	O
X	B-Operating_System
session	B-Protocol
manager	I-Protocol
saves	O
and	O
restores	O
the	O
state	O
of	O
sessions	O
.	O
</s>
<s>
Most	O
recognizably	O
,	O
using	O
a	O
session	B-Protocol
manager	I-Protocol
permits	O
a	O
user	O
to	O
log	O
out	O
from	O
an	O
interactive	O
session	B-Protocol
but	O
to	O
find	O
exactly	O
the	O
same	O
windows	O
in	O
the	O
same	O
state	O
when	O
logging	O
in	O
again	O
.	O
</s>
<s>
For	O
this	O
to	O
work	O
,	O
the	O
session	B-Protocol
manager	I-Protocol
program	O
stores	O
the	O
names	O
of	O
the	O
running	O
applications	O
at	O
logout	O
and	O
starts	O
them	O
again	O
at	O
login	O
.	O
</s>
<s>
In	O
order	O
for	O
the	O
state	O
of	O
the	O
applications	O
to	O
be	O
restored	O
as	O
well	O
(	O
which	O
is	O
needed	O
to	O
restore	O
the	O
content	O
of	O
windows	O
)	O
,	O
the	O
applications	O
must	O
be	O
able	O
to	O
save	O
their	O
state	O
of	O
execution	O
upon	O
request	O
from	O
the	O
session	B-Protocol
manager	I-Protocol
and	O
load	O
it	O
back	O
when	O
they	O
start	O
again	O
.	O
</s>
<s>
The	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
includes	O
a	O
default	O
session	B-Protocol
manager	I-Protocol
called	O
xsm	O
.	O
</s>
<s>
Developers	O
have	O
written	O
other	O
session	B-Protocol
managers	O
for	O
specific	O
desktop	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
Major	O
examples	O
include	O
,	O
,	O
and	O
for	O
KDE	B-Application
,	O
Xfce	B-Language
,	O
and	O
GNOME	B-Application
respectively	O
.	O
</s>
<s>
The	O
program	O
known	O
as	O
the	O
X	B-Language
display	I-Language
manager	I-Language
shows	O
the	O
graphical	O
login	O
prompt	O
in	O
the	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
.	O
</s>
<s>
More	O
generally	O
,	O
a	O
display	B-Device
manager	I-Device
runs	O
one	O
or	O
more	O
X	B-Operating_System
servers	I-Operating_System
on	O
the	O
local	O
computer	O
or	O
accepts	O
incoming	O
connections	O
from	O
X	B-Operating_System
servers	I-Operating_System
running	O
on	O
remote	O
computers	O
.	O
</s>
<s>
The	O
local	O
servers	O
are	O
started	O
by	O
the	O
display	B-Device
manager	I-Device
,	O
which	O
then	O
connects	O
to	O
them	O
to	O
present	O
the	O
user	O
the	O
login	O
screen	O
.	O
</s>
<s>
The	O
remote	O
servers	O
are	O
started	O
independently	O
from	O
the	O
display	B-Device
manager	I-Device
and	O
connect	O
to	O
it	O
.	O
</s>
<s>
In	O
this	O
situation	O
,	O
the	O
display	B-Device
manager	I-Device
works	O
like	O
a	O
graphical	O
telnet	B-Protocol
server	O
:	O
an	O
X	B-Operating_System
server	O
can	O
connect	O
to	O
the	O
display	B-Device
manager	I-Device
,	O
which	O
starts	O
a	O
session	B-Protocol
;	O
the	O
applications	O
which	O
utilize	O
this	O
session	B-Protocol
run	O
on	O
the	O
same	O
computer	O
of	O
the	O
display	B-Device
manager	I-Device
but	O
have	O
input	O
and	O
output	O
on	O
the	O
computer	O
where	O
the	O
X	B-Operating_System
server	O
runs	O
(	O
which	O
may	O
be	O
the	O
computer	O
in	O
front	O
of	O
the	O
user	O
or	O
a	O
remote	O
one	O
)	O
.	O
</s>
<s>
The	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
ships	O
with	O
XDM	B-Language
as	O
the	O
basic	O
supplied	O
display	B-Device
manager	I-Device
.	O
</s>
<s>
Other	O
display	B-Device
managers	I-Device
include	O
GDM	B-Language
(	O
GNOME	B-Application
)	O
,	O
KDM/SDDM	O
(	O
KDE	B-Application
)	O
,	O
WDM	B-Device
(	O
using	O
the	O
WINGs	O
widget	B-Library
set	I-Library
used	O
in	O
Window	B-Application
Maker	I-Application
)	O
and	O
entrance	B-Device
(	O
using	O
the	O
architecture	O
used	O
in	O
Enlightenment	B-Application
v.17	O
)	O
.	O
</s>
<s>
Early	O
widget	B-Library
toolkits	I-Library
for	O
X	B-Operating_System
included	O
Xaw	B-Library
(	O
the	O
Athena	B-Library
Widget	I-Library
Set	I-Library
,	O
1983	O
)	O
,	O
OLIT	B-Library
(	O
OPEN	B-Operating_System
LOOK	I-Operating_System
Intrinsics	B-Language
Toolkit	O
,	O
1988	O
)	O
,	O
XView	B-Library
(	O
1988	O
)	O
,	O
Motif	B-Application
(	O
1980s	O
)	O
and	O
Tk	B-Application
.	O
</s>
<s>
OLIT	B-Library
and	O
XView	B-Library
function	O
as	O
the	O
base	O
toolkits	O
for	O
Sun	O
's	O
legacy	O
OpenWindows	O
desktop	O
environment	O
.	O
</s>
<s>
Motif	B-Application
provides	O
the	O
base	O
toolkit	O
for	O
the	O
Common	B-Application
Desktop	I-Application
Environment	I-Application
(	O
CDE	O
)	O
,	O
the	O
desktop	O
environment	O
used	O
on	O
commercial	O
Unix	B-Application
systems	I-Application
such	O
as	O
Solaris	B-Application
,	O
AIX	B-Application
and	O
HP-UX	B-Application
.	O
</s>
<s>
(	O
Solaris	B-Application
10	I-Application
includes	O
both	O
CDE	O
and	O
GNOME	B-Application
,	O
with	O
the	O
latter	O
the	O
preferred	O
desktop	O
environment	O
.	O
)	O
</s>
<s>
Toolkits	O
developed	O
more	O
recently	O
include	O
Qt	B-Language
(	O
1991	O
-	O
,	O
used	O
by	O
KDE	B-Application
)	O
,	O
GTK+	B-Application
(	O
1997	O
-	O
,	O
used	O
by	O
GNOME	B-Application
)	O
,	O
wxWidgets	B-Language
(	O
1992	O
-	O
)	O
,	O
FLTK	B-Language
(	O
1998	O
-	O
)	O
,	O
FOX	B-Language
(	O
1997	O
-	O
)	O
and	O
fpGUI	B-Language
(	O
2005-current	O
)	O
.	O
</s>
<s>
Scheifler	O
and	O
Gettys	O
designed	O
the	O
X	B-Operating_System
server	O
to	O
be	O
simple	O
but	O
extensible	O
.	O
</s>
<s>
Adding	O
extensions	O
to	O
current	O
X	B-Operating_System
server	O
implementations	O
is	O
reportedly	O
difficult	O
due	O
to	O
a	O
lack	O
of	O
modularity	O
in	O
the	O
server	O
design	O
.	O
</s>
<s>
It	O
is	O
a	O
long-term	O
goal	O
of	O
the	O
XCB	B-Language
project	O
to	O
automate	O
generating	O
both	O
the	O
client	O
and	O
server	O
sides	O
of	O
extensions	O
from	O
XML	O
protocol	O
descriptions	O
.	O
</s>
<s>
XFixes	B-Device
Several	O
protocol	O
changes	O
.	O
</s>
<s>
Extended-Visual-Information	O
(	O
EVIE	O
)	O
Allows	O
client	O
to	O
determine	O
information	O
about	O
core	O
X	B-Operating_System
visuals	O
beyond	O
what	O
the	O
core	O
protocol	O
provides	O
.	O
</s>
<s>
Distributed	O
Multihead	O
(	O
DMX	O
)	O
Communicates	O
with	O
DMX	O
X	B-Operating_System
server	O
.	O
</s>
<s>
X-Video	B-Protocol
Motion	I-Protocol
Compensation	I-Protocol
(	O
XvMC	B-Protocol
)	O
Offloading	O
video	O
motion	O
compensation	O
to	O
a	O
GPU	O
that	O
supports	O
it	O
.	O
</s>
<s>
GLX	B-Device
Support	O
for	O
rendering	O
OpenGL	B-Application
within	O
windows	O
.	O
</s>
<s>
XRender	B-Device
Hardware	O
accelerated	O
image	O
compositing	O
with	O
alpha	O
blending	O
.	O
</s>
<s>
Resize	O
and	O
Rotate	O
(	O
RANDR	O
)	O
Dynamically	O
change	O
the	O
size	O
,	O
reflection	O
,	O
rotation	O
and	O
refresh	O
rate	O
of	O
an	O
X	B-Operating_System
screen	O
.	O
</s>
<s>
Xinerama	B-Device
Splitting	O
the	O
desktop	O
across	O
multiple	O
monitors	O
.	O
</s>
<s>
Display	B-General_Concept
Power	I-General_Concept
Management	I-General_Concept
Signaling	I-General_Concept
(	O
DPMS	B-General_Concept
)	O
Allows	O
controlling	O
monitor	O
power	O
saving	O
modes	O
.	O
</s>
<s>
X	B-Application
keyboard	I-Application
extension	I-Application
Enhanced	O
keyboard	O
layout	O
handling	O
.	O
</s>
<s>
RECORD	O
Used	O
in	O
server	O
testing	O
MIT-SHM	B-Device
Use	O
of	O
shared	O
memory	O
to	O
improve	O
performance	O
.	O
</s>
<s>
SYNC	O
Provides	O
timers	O
and	O
synchronizes	O
clients	O
(	O
e.g.	O
</s>
<s>
running	O
on	O
different	O
hosts	O
and	O
operating	B-General_Concept
systems	I-General_Concept
)	O
from	O
within	O
the	O
X	B-Operating_System
server	O
.	O
</s>
<s>
Use	O
i.e.	O
</s>
<s>
XC-MISC	O
Fixes	O
resource	O
ID	O
range	O
overrun	O
X	B-Protocol
video	I-Protocol
extension	I-Protocol
Support	O
for	O
hardware	O
video	O
overlays	O
and	O
hardware-based	O
video	O
scaling	O
on	O
playback	O
.	O
</s>
<s>
Also	O
called	O
Xv	B-Application
(	O
not	O
to	O
be	O
confused	O
with	O
the	O
xv	B-Application
program	O
)	O
.	O
</s>
<s>
Shape	B-Device
Support	O
for	O
non-rectangular	O
and	O
partially	O
transparent	O
(	O
binary	O
,	O
no	O
alpha	O
opacity	O
)	O
windows	O
.	O
</s>
<s>
MIT-SCREEN-SAVER	O
Launches	O
a	O
program	O
when	O
the	O
X	B-Operating_System
server	O
turns	O
on	O
the	O
built-in	O
screen	O
saver	O
SECURITY	O
Provides	O
enhanced	O
server	O
security	O
X-Resource	O
Allows	O
querying	O
the	O
X	B-Operating_System
server	O
about	O
its	O
resource	O
usage	O
XFree86-Bigfont	O
XFree86-DGA	O
Provides	O
direct	O
linear	O
framebuffer	O
access	O
(	O
direct	O
graphics	O
access	O
)	O
.	O
</s>
<s>
To	O
be	O
mostly	O
removed	O
in	O
X.Org	O
7.6Disable	O
XFree86-DGA	O
requests	O
except	O
relative	O
mouse	O
motion	O
,	O
until	O
Xinput	O
2	O
allows	O
killing	O
it	O
all	O
.	O
</s>
<s>
X.Org	O
Wiki	O
-	O
Releases/7.6	O
XFree86-VidModeExtension	O
Dynamically	O
configures	O
modelines	O
and	O
gamma	O
.	O
</s>
<s>
Extension	O
Description	O
and	O
notes	O
Low	B-Device
Bandwidth	I-Device
X	I-Device
(	O
LBX	B-Device
)	O
Replaced	O
by	O
VNC	B-Protocol
tunneled	B-Protocol
over	O
a	O
secure	O
shell	O
connection	O
,	O
proved	O
faster	O
than	O
LBX	B-Device
.	O
</s>
<s>
PEX	B-Library
"	O
PHIGS	B-Library
Extension	O
to	O
X	B-Operating_System
"	O
;	O
support	O
for	O
PHIGS	B-Library
3D	O
scene	O
graph	O
API	O
.	O
</s>
<s>
GLX	B-Device
with	O
OpenGL	B-Application
is	O
frequently	O
used	O
instead	O
.	O
</s>
<s>
XImage	O
Extension	O
MIT-SHM	B-Device
is	O
used	O
instead	O
.	O
</s>
<s>
XEvIE	B-Protocol
X	B-Operating_System
Event	O
Interception	O
Extension	O
.	O
</s>
<s>
Removed	O
in	O
X.Org	O
7.5.7.5	O
release	O
announcement	O
XFree86-Misc	O
Superseded	O
by	O
input	O
properties	O
.	O
</s>
<s>
Removed	O
in	O
X.Org	O
7.5	O
.	O
</s>
<s>
DEC-XTRAP	O
XTrap	O
allows	O
a	O
controlling	O
X	B-Operating_System
client	O
to	O
emulate	O
a	O
real	O
user	O
's	O
interaction	O
with	O
an	O
X	B-Operating_System
workstation	O
.	O
</s>
<s>
Removed	O
in	O
X.Org	O
7.5	O
.	O
</s>
<s>
Removed	O
in	O
X.Org	O
7.5	O
.	O
</s>
<s>
MIT-SUNDRY-NONSTANDARD	O
Support	O
for	O
various	O
backwards	O
compatibility	O
features	O
for	O
clients	O
which	O
used	O
early	O
implementations	O
of	O
X11	B-Operating_System
.	O
</s>
<s>
For	O
compatibility	O
with	O
Pre-X11R4	O
clients	O
.	O
</s>
<s>
Removed	O
in	O
X.Org	O
7.5	O
.	O
</s>
<s>
XC-APPGROUP	O
Removed	O
in	O
X.Org	O
7.5	O
.	O
</s>
<s>
XPRINT	B-Language
Deprecated	O
.	O
</s>
