<s>
f2c	B-Language
is	O
a	O
program	O
to	O
convert	B-Language
Fortran	O
77	O
to	O
C	B-Language
code	O
,	O
developed	O
at	O
Bell	O
Laboratories	O
.	O
</s>
<s>
The	O
standalone	O
f2c	B-Language
program	O
was	O
based	O
on	O
the	O
core	O
of	O
the	O
first	O
complete	O
Fortran	O
77	O
compiler	B-Language
to	O
be	O
implemented	O
,	O
the	O
"	O
f77	O
"	O
program	O
by	O
Feldman	O
and	O
Weinberger	O
.	O
</s>
<s>
Because	O
the	O
f77	O
compiler	B-Language
was	O
itself	O
written	O
in	O
C	B-Language
and	O
relied	O
on	O
a	O
C	B-Language
compiler	B-Language
back	O
end	O
to	O
complete	O
its	O
final	O
compilation	B-Language
step	O
,	O
it	O
and	O
its	O
derivatives	O
like	O
f2c	B-Language
were	O
much	O
more	O
portable	O
than	O
compilers	B-Language
generating	O
machine	B-Language
code	I-Language
directly	O
.	O
</s>
<s>
The	O
f2c	B-Language
program	O
was	O
released	O
as	O
free	B-Application
software	I-Application
and	O
subsequently	O
became	O
one	O
of	O
the	O
most	O
common	O
means	O
to	O
compile	B-Language
Fortran	O
code	O
on	O
many	O
systems	O
where	O
native	O
Fortran	O
compilers	B-Language
were	O
unavailable	O
or	O
expensive	O
.	O
</s>
<s>
Several	O
large	O
Fortran	O
libraries	O
,	O
such	O
as	O
LAPACK	B-Application
,	O
were	O
made	O
available	O
as	O
C	B-Language
libraries	O
via	O
conversion	O
with	O
f2c	B-Language
.	O
</s>
<s>
The	O
f2c	B-Language
program	O
also	O
influenced	O
the	O
development	O
of	O
the	O
GNU	B-Application
g77	I-Application
compiler	I-Application
,	O
which	O
uses	O
a	O
modified	O
version	O
of	O
the	O
f2c	B-Language
runtime	B-Library
libraries	I-Library
.	O
</s>
