<s>
X.Org	O
Server	O
is	O
the	O
free	B-License
and	I-License
open-source	I-License
implementation	O
of	O
the	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
display	O
server	O
stewarded	O
by	O
the	O
X.Org	B-Application
Foundation	I-Application
.	O
</s>
<s>
Implementations	O
of	O
the	O
client-side	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
protocol	O
exist	O
in	O
the	O
form	O
of	O
X11	B-Operating_System
libraries	O
,	O
which	O
serve	O
as	O
helpful	O
APIs	O
for	O
communicating	O
with	O
the	O
X	B-Operating_System
server	O
.	O
</s>
<s>
Two	O
such	O
major	O
X	B-Language
libraries	I-Language
exist	O
for	O
X11	B-Operating_System
.	O
</s>
<s>
The	O
first	O
of	O
these	O
libraries	O
was	O
Xlib	B-Language
,	O
the	O
original	O
C	B-Language
language	I-Language
X11	B-Operating_System
API	O
,	O
but	O
another	O
C	B-Language
language	I-Language
X	B-Language
library	I-Language
,	O
XCB	B-Language
,	O
was	O
created	O
later	O
in	O
2001	O
.	O
</s>
<s>
Other	O
smaller	O
X	B-Language
libraries	I-Language
exist	O
,	O
both	O
as	O
interfaces	O
for	O
Xlib	B-Language
and	O
XCB	B-Language
in	O
other	O
languages	O
,	O
and	O
as	O
smaller	O
standalone	O
X	B-Language
libraries	I-Language
.	O
</s>
<s>
The	O
services	O
with	O
which	O
the	O
X.Org	B-Application
Foundation	I-Application
supports	O
X	B-Operating_System
Server	O
include	O
the	O
packaging	O
of	O
the	O
releases	O
;	O
certification	O
(	O
for	O
a	O
fee	O
)	O
;	O
evaluation	O
of	O
improvements	O
to	O
the	O
code	O
;	O
developing	O
the	O
web	O
site	O
,	O
and	O
handling	O
the	O
distribution	O
of	O
monetary	O
donations	O
.	O
</s>
<s>
The	O
releases	O
are	O
coded	O
,	O
documented	O
,	O
and	O
packaged	O
by	O
global	O
developers	B-Application
.	O
</s>
<s>
The	O
X.Org	O
Server	O
implements	O
the	O
server	O
side	O
of	O
the	O
X	B-Device
Window	I-Device
System	I-Device
core	I-Device
protocol	I-Device
version	O
11	O
(	O
X11	B-Operating_System
)	O
and	O
extensions	O
to	O
it	O
,	O
e.g.	O
</s>
<s>
Version	O
1.16.0	O
integrates	O
support	O
for	O
systemd-based	O
launching	O
and	O
management	O
which	O
improved	O
boot	O
performance	O
and	O
reliability	O
.	O
</s>
<s>
The	O
Device	B-Operating_System
Independent	I-Operating_System
X	B-Operating_System
(	O
DIX	O
)	O
is	O
the	O
part	O
of	O
the	O
X.Org	O
Server	O
that	O
interacts	O
with	O
clients	O
and	O
implements	O
software	O
rendering	O
.	O
</s>
<s>
An	O
X	B-Operating_System
server	O
has	O
a	O
tremendous	O
amount	O
of	O
functionality	O
that	O
must	O
be	O
implemented	O
to	O
support	O
the	O
X	B-Operating_System
core	O
protocol	O
.	O
</s>
<s>
This	O
includes	O
code	O
tables	O
,	O
glyph	O
rasterization	O
and	O
caching	O
,	O
XLFDs	B-Application
,	O
and	O
the	O
core	O
rendering	O
API	O
which	O
draws	O
graphics	O
primitives	O
.	O
</s>
<s>
The	O
Device	O
Dependent	O
X	B-Operating_System
(	O
DDX	O
)	O
is	O
the	O
part	O
of	O
the	O
x-server	B-Operating_System
that	O
interacts	O
with	O
the	O
hardware	O
.	O
</s>
<s>
In	O
the	O
X.Org	O
Server	O
source	O
code	O
,	O
each	O
directory	O
under	O
"	O
hw	O
"	O
corresponds	O
to	O
one	O
DDX	O
.	O
</s>
<s>
Hardware	O
comprises	O
graphics	B-Device
cards	I-Device
as	O
well	O
as	O
mouse	O
and	O
keyboards	O
.	O
</s>
<s>
For	O
historical	O
reasons	O
the	O
X.Org	O
Server	O
still	O
contains	O
graphics	O
device	O
drivers	O
supporting	O
some	O
form	O
of	O
2D	O
rendering	O
acceleration	O
.	O
</s>
<s>
In	O
the	O
past	O
,	O
mode-setting	B-Operating_System
was	O
done	O
by	O
an	O
X-server	B-Operating_System
graphics	O
device	O
driver	O
specific	O
to	O
some	O
video	B-Device
controller	I-Device
hardware	O
(	O
e.g.	O
,	O
a	O
GPU	B-Architecture
)	O
.	O
</s>
<s>
To	O
this	O
mode-setting	B-Operating_System
functionality	O
,	O
additional	O
support	O
for	O
2D	O
acceleration	O
was	O
added	O
when	O
such	O
became	O
available	O
with	O
various	O
GPUs	B-Architecture
.	O
</s>
<s>
The	O
mode-setting	B-Operating_System
functionality	O
was	O
moved	O
into	O
the	O
DRM	B-Application
and	O
is	O
being	O
exposed	O
through	O
a	O
DRM	B-Application
mode-setting	B-Operating_System
interface	O
,	O
the	O
new	O
approach	O
being	O
called	O
"	O
kernel	B-Operating_System
mode-setting	I-Operating_System
"	O
(	O
KMS	O
)	O
.	O
</s>
<s>
In	O
Debian	O
the	O
2D	O
graphics	O
drivers	O
for	O
the	O
X.Org	O
Server	O
are	O
packaged	O
individually	O
and	O
called	O
xserver-xorg-video-*	O
.	O
</s>
<s>
The	O
package	O
xserver-xorg-video-nouveau	O
installs	O
nouveau_drv.so	O
with	O
a	O
size	O
of	O
215	O
KiB	O
,	O
the	O
proprietary	O
Nvidia	B-Application
GeForce	I-Application
driver	I-Application
installs	O
an	O
8	O
MiB-sized	O
file	O
called	O
nvidia_drv.so	O
and	O
Radeon	B-Application
Software	I-Application
installs	O
fglrx_drv.so	O
with	O
a	O
size	O
of	O
about	O
25MiB	O
.	O
</s>
<s>
The	O
available	O
free	B-Application
and	I-Application
open-source	I-Application
graphics	I-Application
device	I-Application
drivers	I-Application
are	O
being	O
developed	O
inside	O
of	O
the	O
Mesa	O
3D-project	O
.	O
</s>
<s>
While	O
these	O
can	O
be	O
recompiled	O
as	O
required	O
,	O
the	O
development	O
of	O
the	O
proprietary	O
DDX	O
2D	O
graphics	O
drivers	O
is	O
greatly	O
eased	O
when	O
the	O
X.Org	O
Server	O
keeps	O
a	O
stable	O
API/ABI	O
across	O
multiple	O
of	O
its	O
versions	O
.	O
</s>
<s>
With	O
version	O
1.17	O
a	O
generic	O
method	O
for	O
mode-setting	B-Operating_System
was	O
mainlined	O
.	O
</s>
<s>
The	O
xf86-video-modesetting	O
package	O
,	O
the	O
Debian-package	O
being	O
called	O
xserver-xorg-video-modesetting	O
,	O
was	O
retired	O
,	O
and	O
the	O
generic	O
modesetting	B-Operating_System
DDX	O
it	O
contained	O
was	O
moved	O
into	O
the	O
server	O
package	O
to	O
become	O
the	O
KMS-enabled	O
default	O
DDX	O
,	O
supporting	O
the	O
vast	O
majority	O
of	O
AMD	O
,	O
Intel	O
and	O
NVidia	O
GPUs	B-Architecture
.	O
</s>
<s>
On	O
April	O
7	O
,	O
2016	O
AMD	O
employee	O
Michel	O
Dänzer	O
released	O
xf86-video-ati	O
version	O
7.7.0	O
and	O
xf86-video-amdgpu	O
version	O
1.1.0	O
,	O
the	O
latter	O
including	O
support	O
for	O
their	O
Polaris	O
microarchitecture	O
.	O
</s>
<s>
There	O
are	O
(	O
at	O
least	O
)	O
XAA	B-Library
(	O
XFree86	B-Library
Acceleration	I-Library
Architecture	I-Library
)	O
,	O
EXA	B-Library
,	O
UXA	B-Library
and	O
SNA	B-Library
.	O
</s>
<s>
In	O
the	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
,	O
XFree86	B-Library
Acceleration	I-Library
Architecture	I-Library
(	O
XAA	B-Library
)	O
is	O
a	O
driver	O
architecture	O
to	O
make	O
a	O
video	B-Device
card	I-Device
's	O
2D	O
hardware	B-General_Concept
acceleration	I-General_Concept
available	O
to	O
the	O
X	B-Operating_System
server	O
.	O
</s>
<s>
It	O
was	O
written	O
by	O
Harm	O
Hanemaayer	O
in	O
1996	O
and	O
first	O
released	O
in	O
XFree86	B-Device
version	O
3.3	O
.	O
</s>
<s>
It	O
was	O
completely	O
rewritten	O
for	O
XFree86	B-Device
4.0	O
.	O
</s>
<s>
It	O
was	O
removed	O
again	O
from	O
X.Org	O
Server	O
1.13	O
.	O
</s>
<s>
Most	O
drivers	O
implement	O
acceleration	O
using	O
the	O
XAA	B-Library
module	O
.	O
</s>
<s>
XAA	B-Library
is	O
on	O
by	O
default	O
,	O
though	O
acceleration	O
of	O
individual	O
functions	O
can	O
be	O
switched	O
off	O
as	O
needed	O
in	O
the	O
server	O
configuration	O
file	O
(	O
XF86Config	O
or	O
xorg.conf	B-Protocol
)	O
.	O
</s>
<s>
The	O
driver	O
for	O
the	O
ARK	O
chipset	O
was	O
the	O
original	O
development	O
platform	O
for	O
XAA	B-Library
.	O
</s>
<s>
In	O
X.Org	O
Server	O
release	O
6.9/7.0	O
,	O
EXA	B-Library
was	O
released	O
as	O
a	O
replacement	O
for	O
XAA	B-Library
,	O
as	O
XAA	B-Library
supplies	O
almost	O
no	O
speed	O
advantage	O
for	O
current	O
video	B-Device
cards	I-Device
.	O
</s>
<s>
EXA	B-Library
is	O
regarded	O
as	O
an	O
intermediate	O
step	O
to	O
converting	O
the	O
entire	O
X	B-Operating_System
server	O
to	O
using	O
OpenGL	B-Application
.	O
</s>
<s>
Glamor	O
is	O
a	O
generic	O
,	O
hardware	O
independent	O
,	O
2D	O
acceleration	O
driver	O
for	O
the	O
X	B-Operating_System
server	O
that	O
translates	O
the	O
X	B-Operating_System
render	O
primitives	O
into	O
OpenGL	B-Application
operations	O
,	O
taking	O
advantage	O
of	O
any	O
existing	O
3D	O
OpenGL	B-Application
drivers	O
.	O
</s>
<s>
The	O
ultimate	O
goal	O
of	O
GLAMOR	O
is	O
to	O
obsolete	O
and	O
replace	O
all	O
the	O
DDX	O
2D	O
graphics	O
device	O
drivers	O
and	O
acceleration	O
architectures	O
,	O
thereby	O
avoiding	O
the	O
need	O
to	O
write	O
X	B-Operating_System
2D	O
specific	O
drivers	O
for	O
every	O
supported	O
graphic	O
chipset	O
.	O
</s>
<s>
Glamor	O
performance	O
tuning	O
was	O
accepted	O
for	O
Google	B-Application
Summer	I-Application
of	I-Application
Code	I-Application
2014	O
.	O
</s>
<s>
Glamor	O
supports	O
Xephyr	B-Device
and	O
DRI3	O
,	O
and	O
can	O
boost	O
some	O
operations	O
by	O
700	O
–	O
800%	O
.	O
</s>
<s>
Since	O
its	O
mainlining	O
into	O
version	O
1.16	O
of	O
the	O
X.Org	O
Server	O
,	O
development	O
on	O
Glamor	O
was	O
continued	O
and	O
patches	O
for	O
the	O
1.17	O
release	O
were	O
published	O
.	O
</s>
<s>
There	O
is	O
a	O
distinct	O
and	O
special	O
DDX	O
for	O
instances	O
of	O
the	O
X.Org	O
Server	O
which	O
run	O
on	O
a	O
guest	O
system	O
inside	O
of	O
a	O
virtualized	B-General_Concept
environment	I-General_Concept
:	O
xf86-video-qxl	O
,	O
a	O
driver	O
for	O
the	O
"	O
QXL	O
video	O
device	O
"	O
.	O
</s>
<s>
SPICE	B-Protocol
makes	O
use	O
of	O
this	O
driver	O
though	O
it	O
works	O
without	O
it	O
as	O
well	O
.	O
</s>
<s>
With	O
version	O
1.16	O
,	O
the	O
X.Org	O
Server	O
obtained	O
support	O
for	O
the	O
libinput	B-Language
library	O
in	O
form	O
of	O
a	O
wrapper	O
called	O
xf86-input-libinput	O
.	O
</s>
<s>
xserver-xorg-input-joystick	O
is	O
the	O
input	O
module	O
for	O
the	O
X.Org	O
server	O
to	O
handle	O
classic	O
joysticks	O
and	O
gamepads	O
,	O
which	O
is	O
not	O
meant	O
for	O
playing	O
games	O
under	O
X	B-Operating_System
,	O
but	O
to	O
control	O
the	O
cursor	O
with	O
a	O
joystick	O
or	O
gamepad	O
.	O
</s>
<s>
XWayland	B-Application
is	O
a	O
series	O
of	O
patches	O
over	O
the	O
X.Org	O
server	O
codebase	O
that	O
implement	O
an	O
X	B-Operating_System
server	O
running	O
upon	O
the	O
Wayland	B-Language
protocol	O
.	O
</s>
<s>
The	O
patches	O
are	O
developed	O
and	O
maintained	O
by	O
the	O
Wayland	B-Language
developers	B-Application
for	O
compatibility	O
with	O
X11	B-Operating_System
applications	O
during	O
the	O
transition	O
to	O
Wayland	B-Language
,	O
and	O
was	O
mainlined	O
in	O
version	O
1.16	O
of	O
the	O
X.Org	O
Server	O
in	O
2014	O
.	O
</s>
<s>
When	O
a	O
user	O
runs	O
an	O
X	B-Operating_System
application	O
from	O
within	O
Weston	B-Language
,	O
it	O
calls	O
upon	O
XWayland	B-Application
to	O
service	O
the	O
request	O
.	O
</s>
<s>
XQuartz	B-Operating_System
is	O
a	O
series	O
of	O
patches	O
from	O
Apple	O
Inc	O
.	O
to	O
integrate	O
support	O
for	O
the	O
X11	B-Operating_System
protocol	O
into	O
their	O
Quartz	O
Compositor	O
,	O
in	O
a	O
similar	O
way	O
to	O
how	O
XWayland	B-Application
integrates	O
X11	B-Operating_System
into	O
Wayland	B-Language
compositors	O
.	O
</s>
<s>
Xspice	O
is	O
a	O
device	O
driver	O
for	O
the	O
X.Org	O
Server	O
.	O
</s>
<s>
It	O
supports	O
the	O
QXL	O
framebuffer	O
device	O
and	O
includes	O
a	O
wrapper	O
script	O
which	O
makes	O
it	O
possible	O
to	O
launch	O
an	O
X.Org	O
Server	O
whose	O
display	O
is	O
exported	O
via	O
the	O
SPICE	B-Protocol
protocol	I-Protocol
.	O
</s>
<s>
This	O
enables	O
use	O
of	O
SPICE	B-Protocol
in	O
a	O
remote	O
desktop	O
environment	O
,	O
without	O
requiring	O
KVM	B-Application
virtualization	B-General_Concept
.	O
</s>
<s>
Xephyr	B-Device
is	O
an	O
X-on-X	O
implementation	O
.	O
</s>
<s>
Since	O
version	O
1.16.0	O
,	O
Xephyr	B-Device
serves	O
as	O
the	O
primary	O
development	O
environment	O
for	O
the	O
new	O
2D	O
acceleration	O
subsystem	O
(	O
Glamor	O
)	O
,	O
permitting	O
rapid	O
development	O
and	O
testing	O
on	O
a	O
single	O
machine	O
.	O
</s>
<s>
RandR	O
(	O
resize	O
and	O
rotate	O
)	O
is	O
a	O
communications	O
protocol	O
written	O
as	O
an	O
extension	O
to	O
the	O
X11	B-Operating_System
protocol	O
.	O
</s>
<s>
XRandR	O
provides	O
the	O
ability	O
to	O
resize	O
,	O
rotate	O
and	O
reflect	O
the	O
root	B-Device
window	I-Device
of	O
a	O
screen	O
.	O
</s>
<s>
The	O
X.Org	O
Server	O
,	O
and	O
any	O
x-client	O
,	O
each	O
run	O
as	O
distinct	O
processes	O
.	O
</s>
<s>
On	O
Unix/Linux	O
,	O
a	O
process	O
knows	O
nothing	O
about	O
any	O
other	O
processes	O
.	O
</s>
<s>
For	O
it	O
to	O
communicate	O
with	O
another	O
process	O
,	O
it	O
is	O
completely	O
and	O
utterly	O
reliant	O
on	O
the	O
kernel	B-Operating_System
to	O
moderate	O
the	O
communication	O
via	O
available	O
inter-process	B-Operating_System
communication	I-Operating_System
(	O
IPC	O
)	O
mechanisms	O
.	O
</s>
<s>
Unix	B-Protocol
domain	I-Protocol
sockets	I-Protocol
are	O
used	O
to	O
communicate	O
with	O
processes	O
running	O
on	O
the	O
same	O
machine	O
.	O
</s>
<s>
Although	O
Internet	B-Protocol
domain	I-Protocol
sockets	I-Protocol
can	O
be	O
used	O
locally	O
,	O
Unix	B-Protocol
domain	I-Protocol
sockets	I-Protocol
are	O
more	O
efficient	O
,	O
since	O
they	O
do	O
not	O
have	O
the	O
protocol	O
overhead	O
(	O
checksums	B-Algorithm
,	O
byte	O
orders	O
,	O
etc	O
.	O
</s>
<s>
X.Org	O
Server	O
does	O
not	O
use	O
D-Bus	B-Language
.	O
</s>
<s>
Sockets	O
are	O
the	O
most	O
common	O
interprocess	B-Operating_System
communication	I-Operating_System
(	O
IPC	O
)	O
method	O
between	O
the	O
processes	O
of	O
the	O
X	B-Operating_System
server	O
and	O
its	O
various	O
X	B-Operating_System
clients	O
.	O
</s>
<s>
It	O
provides	O
the	O
Application	O
Programming	O
Interface	O
(	O
API	O
)	O
for	O
communication	O
in	O
the	O
TCP/IP	O
domain	O
and	O
also	O
locally	O
only	O
in	O
the	O
UNIX	B-Application
domain	O
.	O
</s>
<s>
There	O
are	O
several	O
other	O
APIs	O
described	O
in	O
the	O
X	B-Operating_System
Transport	O
Interface	O
,	O
for	O
instance	O
TLI	O
(	O
Transport	O
Layer	O
Interface	O
)	O
.	O
</s>
<s>
Other	O
options	O
for	O
IPC	O
between	O
for	O
the	O
X	B-Operating_System
client-server	O
,	O
require	O
X	B-Operating_System
Window	I-Operating_System
system	I-Operating_System
extensions	O
,	O
for	O
instance	O
the	O
MIT	B-Device
Shared	I-Device
Memory	I-Device
Extension	I-Device
(	O
MIT-SHM	B-Device
)	O
.	O
</s>
<s>
It	O
consists	O
of	O
at	O
least	O
one	O
graphics	O
device	O
(	O
graphics	B-Device
card	I-Device
or	O
just	O
an	O
output	O
and	O
the	O
attached	O
monitor	O
)	O
and	O
a	O
keyboard	O
and	O
a	O
mouse	O
.	O
</s>
<s>
Due	O
to	O
limitation	O
of	O
the	O
VT	O
system	O
in	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
and	O
of	O
the	O
X	B-Operating_System
core	O
protocol	O
(	O
in	O
particular	O
,	O
how	O
X	B-Operating_System
defines	O
the	O
relation	O
between	O
the	O
root	B-Device
window	I-Device
and	O
an	O
output	O
of	O
the	O
graphics	B-Device
card	I-Device
)	O
,	O
multi-seat	O
does	O
not	O
work	O
out-of-the-box	O
for	O
the	O
usual	O
Linux	B-Application
distribution	I-Application
but	O
necessitates	O
a	O
special	O
configuration	O
.	O
</s>
<s>
The	O
bus-id	O
string	O
has	O
the	O
form	O
bustype:bus:device:function	O
(	O
e.g.	O
,	O
‘	O
PCI:1:0:0	O
’	O
)	O
.	O
</s>
<s>
At	O
present	O
,	O
only	O
isolation	O
of	O
PCI	B-Protocol
devices	O
is	O
supported	O
;	O
i.e.	O
,	O
this	O
option	O
is	O
ignored	O
if	O
bustype	O
is	O
anything	O
other	O
than	O
‘	O
PCI’	O
.	O
</s>
<s>
Only	O
the	O
user	O
on	O
the	O
first	O
monitor	O
has	O
the	O
use	O
of	O
vt	O
consoles	O
and	O
can	O
use	O
++x	O
to	O
select	O
them	O
.	O
</s>
<s>
The	O
other	O
users	O
have	O
a	O
GDM	B-Language
login	O
screen	O
and	O
can	O
use	O
xorg-server	O
normally	O
,	O
but	O
have	O
no	O
vt	O
's	O
.	O
</s>
<s>
Even	O
though	O
a	O
single	O
user	O
can	O
utilize	O
multiple	O
monitors	O
connected	O
to	O
the	O
different	O
ports	O
of	O
a	O
single	O
graphics	B-Device
card	I-Device
(	O
cf	O
.	O
</s>
<s>
RandR	O
)	O
,	O
the	O
method	O
which	O
is	O
based	O
on	O
multiple	O
instances	O
of	O
the	O
xorg-server	O
seems	O
to	O
require	O
multiple	O
PCI	B-Protocol
graphics	B-Device
cards	I-Device
.	O
</s>
<s>
It	O
is	O
possible	O
to	O
configure	O
multi-seat	O
employing	O
only	O
one	O
graphics	B-Device
card	I-Device
,	O
but	O
due	O
to	O
limitations	O
of	O
the	O
X	B-Device
protocol	I-Device
this	O
necessitates	O
the	O
usage	O
of	O
X	B-Operating_System
Display	O
Manager	O
Control	O
Protocol	O
XDMCP	O
.	O
</s>
<s>
There	O
is	O
also	O
Xdmx	O
(	O
Distributed	O
Multihead	O
X	B-Operating_System
)	O
.	O
</s>
<s>
The	O
X.Org	O
Server	O
runs	O
on	O
many	O
free-software	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
,	O
including	O
being	O
adopted	O
for	O
use	O
by	O
most	O
Linux	B-Application
distributions	I-Application
and	O
BSD	B-Operating_System
variants	O
.	O
</s>
<s>
It	O
is	O
also	O
the	O
X	B-Operating_System
server	O
for	O
the	O
Solaris	B-Application
operating	I-Application
system	I-Application
.	O
</s>
<s>
X.Org	O
is	O
also	O
available	O
in	O
the	O
repositories	O
of	O
Minix	B-Operating_System
3	I-Operating_System
.	O
</s>
<s>
Cygwin/X	B-Application
,	O
Cygwin	B-Language
's	O
implementation	O
of	O
the	O
X	B-Operating_System
server	O
for	O
Microsoft	B-Application
Windows	I-Application
,	O
uses	O
the	O
X.Org	O
Server	O
,	O
as	O
do	O
VcXsrv	O
(	O
Visual	B-Application
C++	I-Application
X-server	B-Operating_System
)	O
and	O
Xming	B-Application
.	O
</s>
<s>
SSH	O
clients	O
such	O
as	O
PuTTY	B-Operating_System
allow	O
launching	O
of	O
X	B-Operating_System
applications	O
through	O
X11	B-Operating_System
forwarding	O
on	O
the	O
condition	O
that	O
it	O
is	O
enabled	O
on	O
both	O
the	O
server	O
and	O
client	O
.	O
</s>
<s>
OS	B-Operating_System
X	I-Operating_System
versions	O
prior	O
to	O
Mac	B-Application
OS	I-Application
X	I-Application
Leopard	I-Application
(	O
10.5	O
)	O
shipped	O
with	O
an	O
XFree86-based	O
server	O
,	O
but	O
10.5	O
'	O
s	O
X	B-Operating_System
server	O
adopted	O
the	O
X.Org	O
codebase	O
.	O
</s>
<s>
Starting	O
with	O
OS	B-Operating_System
X	I-Operating_System
Mountain	I-Operating_System
Lion	I-Operating_System
,	O
(	O
10.8	B-Operating_System
)	O
X11	B-Operating_System
is	O
not	O
bundled	O
in	O
OS	B-Operating_System
X	I-Operating_System
;	O
instead	O
,	O
it	O
has	O
to	O
be	O
installed	O
from	O
,	O
for	O
example	O
,	O
the	O
open	O
source	O
XQuartz	B-Operating_System
project	O
.	O
</s>
<s>
As	O
of	O
version	O
2.7.4	O
,	O
X11.app/XQuartz	O
does	O
not	O
expose	O
support	O
for	O
high-resolution	O
Retina	B-Operating_System
displays	I-Operating_System
to	O
X11	B-Operating_System
apps	O
,	O
which	O
run	O
in	O
pixel-doubled	O
mode	O
on	O
high-resolution	O
displays	O
.	O
</s>
<s>
Current	O
versions	O
of	O
the	O
DECwindows	O
X11	B-Operating_System
server	I-Operating_System
for	O
OpenVMS	B-Operating_System
are	O
based	O
on	O
X.org	O
Server	O
.	O
</s>
<s>
The	O
modern	O
X.Org	B-Application
Foundation	I-Application
came	O
into	O
being	O
in	O
2004	O
when	O
the	O
body	O
that	O
oversaw	O
X	B-Operating_System
standards	O
and	O
published	O
the	O
official	O
reference	O
implementation	O
joined	O
forces	O
with	O
former	O
XFree86	B-Device
developers	B-Application
.	O
</s>
<s>
X11R6.7.0	O
,	O
the	O
first	O
version	O
of	O
the	O
X.Org	O
Server	O
,	O
was	O
forked	O
from	O
XFree86	B-Device
4.4	O
RC2	O
.	O
</s>
<s>
The	O
immediate	O
reason	O
for	O
the	O
fork	B-Application
was	O
a	O
disagreement	O
with	O
the	O
new	O
license	O
for	O
the	O
final	O
release	O
version	O
of	O
XFree86	B-Device
4.4	O
,	O
but	O
several	O
disagreements	O
among	O
the	O
contributors	O
surfaced	O
prior	O
to	O
the	O
split	O
.	O
</s>
<s>
Many	O
of	O
the	O
previous	O
XFree86	B-Device
developers	B-Application
have	O
joined	O
the	O
X.Org	O
Server	O
project	O
.	O
</s>
<s>
In	O
2005	O
,	O
a	O
great	O
effort	O
was	O
put	O
in	O
the	O
modularization	O
of	O
the	O
X.Org	O
server	O
source	O
code	O
,	O
resulting	O
in	O
a	O
dual	O
release	O
by	O
the	O
end	O
of	O
the	O
year	O
.	O
</s>
<s>
The	O
X11R7.0.0	O
release	O
added	O
a	O
new	O
modular	O
build	O
system	O
based	O
on	O
the	O
GNU	B-Application
Autotools	I-Application
,	O
while	O
X11R6.9.0	O
kept	O
the	O
old	O
imake	B-Application
build	O
system	O
,	O
both	O
releases	O
sharing	O
the	O
same	O
codebase	O
.	O
</s>
<s>
Since	O
then	O
the	O
X11R6.9	O
branch	O
is	O
maintained	O
frozen	O
and	O
all	O
the	O
ongoing	O
development	O
is	O
done	O
to	O
the	O
modular	O
branch	O
.	O
</s>
<s>
The	O
new	O
build	O
system	O
also	O
brought	O
the	O
use	O
of	O
dlloader	O
standard	O
dynamic	B-Application
linker	I-Application
to	O
load	O
plugins	O
and	O
drivers	O
,	O
deprecating	O
the	O
old	O
own	O
method	O
.	O
</s>
<s>
As	O
a	O
consequence	O
of	O
the	O
modularization	O
,	O
the	O
X11	B-Operating_System
binaries	O
were	O
moving	O
out	O
of	O
their	O
own	O
/usr/X11R6	O
subdirectory	O
tree	O
and	O
into	O
the	O
global	O
/usr	O
tree	O
on	O
many	O
Unix	B-Application
systems	I-Application
.	O
</s>
<s>
In	O
June	O
2006	O
,	O
another	O
effort	O
was	O
done	O
to	O
move	O
the	O
X.Org	O
server	O
source	O
codebase	O
from	O
CVS	B-Application
to	O
git	B-Application
.	O
</s>
<s>
Both	O
efforts	O
had	O
the	O
long-term	O
goal	O
of	O
bringing	O
new	O
developers	B-Application
to	O
the	O
project	O
.	O
</s>
<s>
In	O
the	O
7.1	O
release	O
,	O
the	O
KDrive	O
framework	O
(	O
a	O
small	O
implementation	O
of	O
X	B-Operating_System
written	O
by	O
Keith	O
Packard	O
,	O
which	O
was	O
not	O
based	O
on	O
XFree86	B-Device
that	O
X.Org	O
developers	B-Application
used	O
as	O
a	O
testing	O
ground	O
for	O
new	O
ideas	O
,	O
such	O
as	O
EXA	B-Library
)	O
was	O
integrated	O
into	O
the	O
main	O
codebase	O
of	O
X.Org	O
server	O
.	O
</s>
<s>
In	O
2008	O
,	O
the	O
new	O
DRI2	B-Application
,	O
based	O
on	O
the	O
kernel	B-Operating_System
mode-setting	I-Operating_System
(	O
KMS	O
)	O
driver	O
,	O
replaced	O
DRI	O
.	O
</s>
<s>
This	O
change	O
also	O
set	O
a	O
major	O
milestone	O
in	O
the	O
X.Org	O
server	O
architecture	O
,	O
as	O
the	O
drivers	O
were	O
moved	O
out	O
from	O
the	O
server	O
and	O
user	B-Operating_System
space	I-Operating_System
(	O
UMS	O
)	O
to	O
the	O
kernel	B-Operating_System
space	I-Operating_System
.	O
</s>
<s>
By	O
the	O
end	O
of	O
the	O
year	O
the	O
implementation	O
of	O
GLX	B-Device
was	O
rewritten	O
by	O
Adam	O
Jackson	O
at	O
Red	O
Hat	O
.	O
</s>
