<s>
UMFPACK	B-Language
(	O
)	O
is	O
a	O
set	O
of	O
routines	O
for	O
solving	O
unsymmetric	O
sparse	B-Algorithm
linear	O
systems	O
of	O
the	O
form	O
Ax	O
=	O
b	O
,	O
using	O
the	O
Unsymmetric	O
MultiFrontal	O
method	O
(	O
Matrix	O
A	O
is	O
not	O
required	O
to	O
be	O
symmetric	B-Algorithm
)	O
.	O
</s>
<s>
It	O
appears	O
as	O
a	O
built-in	O
routine	O
(	O
for	O
lu	O
,	O
backslash	O
,	O
and	O
forward	O
slash	O
)	O
in	O
MATLAB	B-Language
,	O
and	O
includes	O
a	O
MATLAB	B-Language
interface	O
,	O
a	O
C-callable	O
interface	O
,	O
and	O
a	O
Fortran-callable	O
interface	O
.	O
</s>
<s>
Note	O
that	O
"	O
UMFPACK	B-Language
"	O
is	O
pronounced	O
in	O
two	O
syllables	O
,	O
"	O
Umph	O
Pack	O
"	O
.	O
</s>
<s>
UMFPACK	B-Language
has	O
installation	O
options	O
to	O
use	O
the	O
many	O
versions	O
of	O
the	O
BLAS	O
,	O
or	O
no	O
BLAS	O
at	O
all	O
.	O
</s>
<s>
BLAS	O
is	O
what	O
UMFPACK	B-Language
relies	O
on	O
,	O
to	O
get	O
high	O
performance	O
on	O
a	O
wide	O
range	O
of	O
computers	O
.	O
</s>
<s>
Versions	O
1	O
and	O
1.1	O
were	O
in	O
Fortran	B-Application
77	O
(	O
Jan	O
.	O
1995	O
)	O
and	O
are	O
licensed	O
for	O
non-commercial	O
only	O
.	O
</s>
<s>
Version	O
2.2	O
appears	O
as	O
the	O
Fortran	B-Application
package	O
MA38	O
in	O
the	O
Harwell	O
Subroutine	O
Library	O
.	O
</s>
<s>
Versions	O
3	O
(	O
March	O
2001	O
)	O
to	O
5.1	O
(	O
May	O
2007	O
)	O
are	O
licensed	O
under	O
the	O
LGPL	B-Application
license	I-Application
.	O
</s>
<s>
Versions	O
5.2	O
(	O
Nov	O
2007	O
)	O
to	O
date	O
are	O
licensed	O
under	O
the	O
GPL	B-License
license	I-License
,	O
with	O
alternative	O
commercial	O
licenses	O
available	O
as	O
well	O
.	O
</s>
