<s>
In	O
computing	O
,	O
EXA	B-Library
is	O
a	O
graphics	O
acceleration	O
architecture	O
of	O
the	O
X.Org	B-Operating_System
Server	I-Operating_System
(	O
see	O
also	O
X	B-Operating_System
Window	I-Operating_System
System	I-Operating_System
)	O
designed	O
to	O
replace	O
XAA	O
(	O
the	O
XFree86	B-Library
Acceleration	I-Library
Architecture	I-Library
)	O
and	O
to	O
make	O
the	O
XRender	B-Device
extension	O
more	O
usable	O
,	O
with	O
only	O
minor	O
changes	O
needed	O
to	O
adapt	O
obsolete	O
XFree86	B-Device
video	O
drivers	O
written	O
to	O
use	O
XAA	O
;	O
it	O
was	O
designed	O
by	O
Zack	O
Rusin	O
and	O
announced	O
at	O
LinuxTag	O
2005	O
and	O
first	O
released	O
with	O
X.Org	B-Operating_System
Server	I-Operating_System
version	O
6.9/7.0	O
.	O
</s>
<s>
2D	O
acceleration	O
was	O
provided	O
by	O
the	O
venerable	O
XFree86	B-Library
Acceleration	I-Library
Architecture	I-Library
,	O
XAA	O
,	O
which	O
made	O
the	O
video	O
card	O
's	O
2D	O
hardware	O
acceleration	O
available	O
to	O
the	O
X	B-Operating_System
server	O
.	O
</s>
<s>
The	O
3D	O
acceleration	O
set	O
was	O
provided	O
via	O
the	O
Direct	B-Application
Rendering	I-Application
Manager	I-Application
,	O
which	O
worked	O
by	O
mapping	O
3D	O
rendered	O
pictures	O
on	O
top	O
of	O
the	O
2D	O
picture	O
.	O
</s>
<s>
This	O
had	O
some	O
buggy	O
corner	O
cases	O
,	O
but	O
more	O
or	O
less	O
worked	O
,	O
until	O
compositing	B-Operating_System
entered	O
into	O
the	O
desktop	O
.	O
</s>
<s>
EXA	B-Library
was	O
introduced	O
as	O
a	O
stopgap	O
measure	O
,	O
to	O
provide	O
better	O
integration	O
with	O
XRender	B-Device
than	O
XAA	O
did	O
,	O
improving	O
the	O
X.Org	B-Operating_System
Server	I-Operating_System
2D	O
performance	O
.	O
</s>
<s>
The	O
solution	O
was	O
to	O
move	O
to	O
hardware	O
acceleration	O
with	O
OpenGL	B-Application
for	O
both	O
2D	O
and	O
3D	O
graphics	O
with	O
2D	O
graphics	O
becoming	O
just	O
a	O
subset	O
of	O
3D	O
rendering	O
.	O
</s>
<s>
EXA	B-Library
was	O
adapted	O
from	O
KAA	O
,	O
the	O
KDrive	B-Operating_System
Acceleration	O
Architecture	O
,	O
from	O
the	O
experimental	O
Freedesktop.org	B-Operating_System
Xserver	I-Operating_System
.	O
</s>
<s>
Many	O
XAA	O
drivers	O
had	O
EXA	B-Library
support	O
added	O
for	O
X11R6.9/7.0	O
and	O
support	O
continues	O
to	O
be	O
added	O
to	O
more	O
drivers	O
.	O
</s>
<s>
UXA	B-Library
is	O
a	O
reimplementation	O
of	O
the	O
EXA	B-Library
API	O
developed	O
by	O
Intel	O
,	O
using	O
the	O
Graphics	O
Execution	O
Manager	O
.	O
</s>
<s>
The	O
Radeon	O
free	O
and	O
open-source	O
device	O
driver	O
supports	O
2D	O
acceleration	O
through	O
EXA	B-Library
and	O
Glamor	B-Application
.	O
</s>
<s>
Glamor	B-Application
is	O
supposed	O
to	O
obsolete	O
all	O
previous	O
attempts	O
.	O
</s>
<s>
According	O
to	O
the	O
X.Org	O
web	O
site	O
EXA	B-Library
is	O
an	O
"	O
acceleration	O
architecture	O
with	O
no	O
well-defined	O
acronym.	O
"	O
</s>
<s>
Dot.kde.org	O
called	O
it	O
"	O
Eyecandy	B-Library
Acceleration	I-Library
Architecture	I-Library
"	O
.	O
</s>
<s>
The	O
driver	O
modification	O
guide	O
calls	O
it	O
"	O
EXcellent	B-Library
Architecture	I-Library
or	O
Ex-kaa	B-Library
aXeleration	I-Library
Architecture	I-Library
or	O
whatever.	O
"	O
</s>
