<s>
GNU	B-Application
Fortran	I-Application
(	O
GFortran	B-Application
)	O
is	O
an	O
implementation	O
of	O
the	O
Fortran	B-Application
programming	I-Application
language	I-Application
in	O
the	O
GNU	B-Application
Compiler	I-Application
Collection	I-Application
(	O
GCC	B-Application
)	O
,	O
an	O
open-source	B-Application
and	O
free	B-Application
software	I-Application
project	O
maintained	O
in	O
the	O
open-source	B-Application
programmer	O
community	O
under	O
the	O
umbrella	O
of	O
the	B-Application
GNU	I-Application
Project	I-Application
.	O
</s>
<s>
It	O
is	O
the	O
successor	O
to	O
previous	O
compiler	B-Language
versions	O
in	O
the	O
suite	O
,	O
such	O
as	O
g77	O
.	O
</s>
<s>
As	O
of	O
July	O
2020	O
,	O
GFortran	B-Application
had	O
almost	O
fully	O
implemented	O
Fortran	B-Application
2008	O
,	O
and	O
about	O
20%	O
of	O
Fortran	B-Application
2018	O
.	O
</s>
<s>
It	O
supports	O
the	O
OpenMP	B-Application
multi-platform	B-Operating_System
shared	B-Operating_System
memory	I-Operating_System
multiprocessing	B-Operating_System
,	O
up	O
to	O
its	O
latest	O
version	O
(	O
4.5	O
)	O
.	O
</s>
<s>
GFortran	B-Application
is	O
also	O
compatible	O
with	O
most	O
language	O
extensions	O
and	O
compilation	B-Language
options	O
supported	O
by	O
g77	O
,	O
and	O
many	O
other	O
popular	O
extensions	O
of	O
the	O
Fortran	B-Application
language	I-Application
.	O
</s>
<s>
Since	O
GCC	B-Application
version	O
4.0.0	O
,	O
released	O
in	O
April	O
2005	O
,	O
GFortran	B-Application
has	O
replaced	O
the	O
older	O
g77	O
compiler	B-Language
.	O
</s>
<s>
The	O
new	O
Fortran	B-Application
front-end	B-Architecture
for	O
GCC	B-Application
was	O
rewritten	O
from	O
scratch	O
,	O
after	O
the	O
principal	O
author	O
and	O
maintainer	O
of	O
g77	O
,	O
Craig	O
Burley	O
,	O
decided	O
in	O
2001	O
to	O
stop	O
working	O
on	O
the	O
g77	O
front	B-Architecture
end	I-Architecture
.	O
</s>
<s>
GFortran	B-Application
forked	B-Application
off	O
from	O
g95	B-Application
in	O
January	O
2003	O
,	O
which	O
itself	O
started	O
in	O
early	O
2000	O
.	O
</s>
<s>
The	O
two	O
codebases	B-General_Concept
have	O
"	O
significantly	O
diverged	O
"	O
according	O
to	O
GCC	B-Application
developers	O
,	O
and	O
g95	B-Application
is	O
not	O
maintained	O
anymore	O
since	O
2013	O
.	O
</s>
<s>
Since	O
2010	O
the	O
front-end	B-Architecture
,	O
like	O
the	O
rest	O
of	O
the	O
GCC	B-Application
project	O
,	O
has	O
been	O
migrated	O
to	O
C++	B-Language
,	O
where	O
it	O
was	O
previously	O
written	O
in	O
C	B-Language
.	O
Development	O
of	O
the	O
compiler	B-Language
by	O
volunteer	O
users	O
continues	O
and	O
each	O
new	O
version	O
of	O
GCC	B-Application
incorporates	O
better	O
support	O
for	O
the	O
latest	O
language	O
standards	O
and	O
bug	O
fixes	O
.	O
</s>
