<s>
In	O
computer	O
software	O
,	O
Orac	B-Application
is	O
a	O
classical	O
molecular	O
dynamics	O
program	O
,	O
to	O
simulate	O
complex	O
molecular	O
systems	O
at	O
the	O
atomistic	O
level	O
.	O
</s>
<s>
It	O
is	O
written	O
in	O
the	O
programming	O
language	O
Fortran	B-Application
.	O
</s>
<s>
In	O
1997	O
,	O
it	O
was	O
released	O
under	O
a	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
(	O
GPL	B-License
)	O
.	O
</s>
<s>
The	O
latest	O
release	O
of	O
Orac	B-Application
may	O
be	O
run	O
in	O
parallel	O
using	O
the	O
standard	O
Message	B-Application
Passing	I-Application
Interface	I-Application
(	O
MPI	O
)	O
libraries	O
,	O
allowing	O
replica	B-Algorithm
exchange	I-Algorithm
simulations	O
,	O
multiple	O
walkers	O
metadynamics	O
simulations	O
and	O
multiple	O
steered	O
molecular	O
dynamics	O
nonequilibrium	O
trajectories	O
.	O
</s>
