<s>
Chaff	O
is	O
an	O
algorithm	O
for	O
solving	O
instances	O
of	O
the	O
Boolean	B-Algorithm
satisfiability	I-Algorithm
problem	I-Algorithm
in	O
programming	O
.	O
</s>
<s>
The	O
algorithm	O
is	O
an	O
instance	O
of	O
the	O
DPLL	B-Application
algorithm	I-Application
with	O
a	O
number	O
of	O
enhancements	O
for	O
efficient	O
implementation	O
.	O
</s>
<s>
Some	O
available	O
implementations	O
of	O
the	O
algorithm	O
in	O
software	O
are	O
mChaff	O
and	O
zChaff	B-Application
,	O
the	O
latter	O
one	O
being	O
the	O
most	O
widely	O
known	O
and	O
used	O
.	O
</s>
<s>
zChaff	B-Application
was	O
originally	O
written	O
by	O
Dr.	O
Lintao	O
Zhang	O
,	O
at	O
Microsoft	O
Research	O
,	O
hence	O
the	O
“	O
z	O
”	O
.	O
</s>
<s>
It	O
is	O
now	O
maintained	O
by	O
researchers	O
at	O
Princeton	O
University	O
and	O
available	O
for	O
download	B-Application
as	O
both	O
source	O
code	O
and	O
binaries	O
on	O
Linux	B-Application
.	O
</s>
<s>
zChaff	B-Application
is	O
free	O
for	O
non-commercial	O
use	O
.	O
</s>
