<s>
HEC-1	B-Application
is	O
software	O
that	O
was	O
developed	O
by	O
the	O
US	O
Army	O
Corps	O
of	O
Engineers	O
to	O
estimate	O
river	O
flows	O
as	O
a	O
result	O
of	O
rainfall	O
.	O
</s>
<s>
It	O
was	O
written	O
in	O
the	O
FORTRAN	B-Application
language	I-Application
and	O
until	O
1984	O
could	O
only	O
be	O
run	O
on	O
a	O
mainframe	B-Architecture
computer	I-Architecture
.	O
</s>
<s>
When	O
desktop	B-Device
computers	I-Device
became	O
popular	O
the	O
program	O
was	O
ported	O
to	O
the	O
PC	B-Device
.	O
</s>
