<s>
Geant4	B-Application
(	O
for	O
GEometry	O
ANd	O
Tracking	O
)	O
is	O
a	O
platform	B-Device
for	O
"	O
the	O
simulation	O
of	O
the	O
passage	O
of	O
particles	O
through	O
matter	O
"	O
using	O
Monte	B-Algorithm
Carlo	I-Algorithm
methods	I-Algorithm
.	O
</s>
<s>
It	O
is	O
the	O
successor	O
of	O
the	O
GEANT	B-Application
series	O
of	O
software	O
toolkits	O
developed	O
by	O
,	O
and	O
the	O
first	O
to	O
use	O
object	B-Language
oriented	I-Language
programming	I-Language
(	O
in	O
C++	B-Language
)	O
.	O
</s>
<s>
Its	O
development	O
,	O
maintenance	O
and	O
user	O
support	O
are	O
taken	O
care	O
by	O
the	O
international	O
Geant4	B-Application
Collaboration	O
.	O
</s>
<s>
The	O
Geant4	B-Application
software	O
and	O
source	O
code	O
is	O
freely	O
available	O
from	O
the	O
project	O
web	O
site	O
;	O
until	O
version	O
8.1	O
(	O
released	O
June	O
28	O
,	O
2006	O
)	O
,	O
no	O
specific	O
software	O
license	O
for	O
its	O
use	O
existed	O
;	O
Geant4	B-Application
is	O
now	O
provided	O
under	O
the	O
.	O
</s>
<s>
Geant4	B-Application
includes	O
facilities	O
for	O
handling	O
geometry	O
,	O
tracking	O
,	O
detector	B-Algorithm
response	O
,	O
run	O
management	O
,	O
visualization	O
and	O
user	B-Application
interface	I-Application
.	O
</s>
<s>
Detector	B-Algorithm
response	O
is	O
recording	O
when	O
a	O
particle	O
passes	O
through	O
the	O
volume	O
of	O
a	O
detector	B-Algorithm
,	O
and	O
approximating	O
how	O
a	O
real	O
detector	B-Algorithm
would	O
respond	O
.	O
</s>
<s>
Geant4	B-Application
offers	O
a	O
number	O
of	O
options	O
for	O
visualization	O
,	O
including	O
OpenGL	B-Application
,	O
Open_Inventor	O
,	O
VRML	B-Application
or	O
VTK	B-Language
and	O
a	O
familiar	O
user	B-Application
interface	I-Application
,	O
based	O
on	O
Tcsh	B-Language
or	O
Qt_(software )	O
.	O
</s>
<s>
Geant4	B-Application
can	O
also	O
perform	O
basic	O
histogramming	O
;	O
it	O
requires	O
external	O
analysis	O
tools	O
for	O
exploiting	O
advanced	O
histogramming	O
features	O
.	O
</s>
<s>
Since	O
release	O
10.0	O
,	O
Geant4	B-Application
implements	O
multithreading	B-Operating_System
,	O
making	O
use	O
of	O
thread-local	O
storage	O
to	O
allow	O
for	O
efficient	O
generation	O
of	O
simulated	O
events	O
in	O
parallel	O
.	O
</s>
<s>
Geant4	B-Application
can	O
be	O
installed	O
under	O
a	O
Unix-based	O
operating	O
system	O
such	O
as	O
MacOS	B-Application
,	O
Linux	B-Application
or	O
under	O
Microsoft_Windows	O
.	O
</s>
<s>
Because	O
of	O
its	O
general	O
purpose	O
nature	O
,	O
Geant4	B-Application
is	O
well	O
suited	O
for	O
development	O
of	O
computational	O
tools	O
for	O
analysing	O
interactions	O
of	O
particle	O
with	O
matter	O
in	O
many	O
areas	O
.	O
</s>
