<s>
Futhark	B-Language
is	O
a	O
functional	B-Language
data	B-Operating_System
parallel	I-Operating_System
array	B-Application
programming	I-Application
language	I-Application
originally	O
developed	O
at	O
DIKU	O
as	O
part	O
of	O
the	O
HIPERFIT	O
project	O
.	O
</s>
<s>
It	O
focuses	O
on	O
enabling	O
data	B-Operating_System
parallel	I-Operating_System
programs	O
written	O
in	O
a	O
functional	B-Language
style	O
to	O
be	O
executed	O
with	O
high	O
performance	O
on	O
massively	O
parallel	O
hardware	O
,	O
in	O
particular	O
on	O
GPUs	O
.	O
</s>
<s>
Futhark	B-Language
is	O
strongly	O
inspired	O
by	O
NESL	B-Language
,	O
and	O
its	O
implementation	O
uses	O
a	O
variant	O
of	O
the	O
flattening	O
transformation	O
,	O
but	O
imposes	O
constraints	O
on	O
how	O
parallelism	O
can	O
be	O
expressed	O
in	O
order	O
to	O
enable	O
more	O
aggressive	O
compiler	O
optimisations	O
.	O
</s>
<s>
In	O
particular	O
,	O
irregular	O
nested	O
data	B-Operating_System
parallelism	I-Operating_System
is	O
not	O
supported	O
.	O
</s>
<s>
Futhark	B-Language
is	O
a	O
language	O
in	O
the	O
ML	B-Algorithm
family	O
,	O
with	O
an	O
indentation-insensitive	O
syntax	O
derived	O
from	O
OCaml	B-Language
,	O
Standard	B-Language
ML	I-Language
,	O
and	O
Haskell	B-Language
.	O
</s>
<s>
The	O
type	O
system	O
is	O
based	O
on	O
Hindley-Milner	B-Algorithm
with	O
a	O
variety	O
of	O
extensions	O
,	O
such	O
as	O
uniqueness	O
types	O
and	O
size-dependent	O
types	O
.	O
</s>
<s>
Futhark	B-Language
is	O
not	O
intended	O
as	O
a	O
general-purpose	B-Language
programming	I-Language
language	I-Language
for	O
writing	O
full	O
applications	O
,	O
but	O
is	O
instead	O
focused	O
on	O
writing	O
computational	O
"	O
kernels	B-Operating_System
"	O
(	O
not	O
necessarily	O
the	O
same	O
as	O
a	O
GPU	B-Operating_System
kernel	I-Operating_System
)	O
which	O
are	O
then	O
invoked	O
from	O
applications	O
written	O
in	O
conventional	O
languages	O
.	O
</s>
<s>
Further	O
,	O
this	O
is	O
an	O
example	O
of	O
nested	O
data	B-Operating_System
parallelism	I-Operating_System
.	O
</s>
