<s>
In	O
computer	B-General_Concept
science	I-General_Concept
,	O
Linda	B-Language
is	O
a	O
coordination	O
model	O
that	O
aids	O
communication	O
in	O
parallel	B-Operating_System
computing	I-Operating_System
environments	O
.	O
</s>
<s>
Developed	O
by	O
David	O
Gelernter	O
,	O
it	O
is	O
meant	O
to	O
be	O
used	O
alongside	O
a	O
full-fledged	O
computation	O
language	O
like	O
Fortran	B-Application
or	O
C	B-Language
where	O
Linda	B-Language
's	O
role	O
is	O
to	O
"	O
create	O
computational	O
activities	O
and	O
to	O
support	O
communication	O
among	O
them	O
"	O
.	O
</s>
<s>
David	O
Gelernter	O
wrote	O
the	O
first	O
version	O
of	O
Linda	B-Language
as	O
a	O
Ph.D.	O
candidate	O
in	O
1979	O
,	O
naming	O
it	O
after	O
Linda	B-Language
Lovelace	O
,	O
who	O
appeared	O
in	O
the	O
pornographic	O
film	O
Deep	O
Throat	O
.	O
</s>
<s>
At	O
the	O
time	O
,	O
the	O
main	O
language	O
for	O
parallel	B-Operating_System
processing	I-Operating_System
was	O
Ada	B-Language
,	O
developed	O
by	O
the	O
U.S.	O
Department	O
of	O
Defense	O
and	O
a	O
tribute	O
to	O
Ada	B-General_Concept
Lovelace	I-General_Concept
,	O
which	O
Gelernter	O
considered	O
an	O
"	O
inelegant	O
and	O
bulky	O
"	O
language	O
.	O
</s>
<s>
It	O
was	O
widely	O
released	O
in	O
1986	O
,	O
when	O
Gelernter	O
,	O
along	O
with	O
his	O
Yale	O
colleague	O
Nicholas	O
Carriero	O
and	O
Sudhir	O
Ahuja	O
at	O
AT&T	O
Bell	O
Laboratories	O
,	O
published	O
"	O
Linda	B-Language
and	O
Friends	O
"	O
in	O
an	O
IEEE	O
journal	O
.	O
</s>
<s>
By	O
the	O
early	O
1990s	O
,	O
Linda	B-Language
was	O
widely	O
used	O
by	O
corporations	O
to	O
more	O
efficiently	O
conduct	O
big	B-Application
data	I-Application
analyses	O
,	O
including	O
Wall	B-Application
Street	I-Application
brokerages	O
as	O
well	O
as	O
AT&T	O
,	O
Boeing	O
,	O
and	O
United	O
Technologies	O
.	O
</s>
<s>
There	O
were	O
even	O
companies	O
that	O
specialized	O
in	O
creating	O
specialized	O
parallel	B-Operating_System
computing	I-Operating_System
applications	O
based	O
on	O
Linda	B-Language
,	O
the	O
largest	O
of	O
which	O
was	O
Scientific	O
Computing	O
Associates	O
,	O
a	O
New	O
Haven-based	O
company	O
founded	O
by	O
several	O
Yale	O
computer	B-General_Concept
scientists	I-General_Concept
(	O
Gelernter	O
occasionally	O
consulted	O
for	O
them	O
but	O
did	O
not	O
work	O
there	O
)	O
.	O
</s>
<s>
Interest	O
in	O
Linda	B-Language
dropped	O
in	O
the	O
mid-1990s	O
,	O
only	O
to	O
make	O
a	O
comeback	O
in	O
the	O
late	O
1990s	O
with	O
several	O
corporations	O
implementing	O
Linda	B-Language
in	O
Java	B-Language
,	O
including	O
Sun	O
Microsystems	O
and	O
IBM	O
.	O
</s>
<s>
The	O
Linda	B-Language
model	O
provides	O
a	O
distributed	B-Operating_System
shared	I-Operating_System
memory	I-Operating_System
,	O
known	O
as	O
a	O
tuple	B-Operating_System
space	I-Operating_System
because	O
its	O
basic	O
addressable	B-General_Concept
unit	I-General_Concept
is	O
a	O
tuple	B-Application
,	O
an	O
ordered	O
sequence	O
of	O
typed	O
data	O
objects	O
;	O
specifically	O
in	O
Linda	B-Language
,	O
a	O
tuple	B-Application
is	O
a	O
sequence	O
of	O
up	O
to	O
16	O
typed	O
fields	O
enclosed	O
in	O
parentheses	O
"	O
.	O
</s>
<s>
The	O
tuple	B-Operating_System
space	I-Operating_System
is	O
"	O
logically	O
shared	O
by	O
processes	O
"	O
which	O
are	O
referred	O
to	O
as	O
workers	O
that	O
store	O
and	O
retrieve	O
tuples	B-Application
.	O
</s>
<s>
One	O
of	O
Linda	B-Language
's	O
main	O
advantages	O
is	O
that	O
it	O
's	O
simple	O
,	O
with	O
only	O
six	O
operations	O
that	O
workers	O
perform	O
on	O
the	O
tuples	B-Application
to	O
access	O
tuplespace	B-Operating_System
:	O
</s>
<s>
Compared	O
to	O
other	O
parallel-processing	O
models	O
,	O
Linda	B-Language
is	O
more	O
orthogonal	O
in	O
treating	O
process	O
coordination	O
as	O
a	O
separate	O
activity	O
from	O
computation	O
,	O
and	O
it	O
is	O
more	O
general	O
in	O
being	O
able	O
to	O
subsume	O
various	O
levels	O
of	O
concurrencyuniprocessor	O
,	O
multi-threaded	O
multiprocessor	O
,	O
or	O
networkedunder	O
a	O
single	O
model	O
.	O
</s>
<s>
Its	O
generality	O
allows	O
a	O
multi-threaded	O
Linda	B-Language
system	O
to	O
be	O
distributed	O
across	O
multiple	O
computers	O
without	O
change	O
.	O
</s>
<s>
Whereas	O
message-passing	O
models	O
require	O
tightly	O
coupled	O
processes	O
sending	O
messages	O
to	O
each	O
other	O
in	O
some	O
sequence	O
or	O
protocol	O
,	O
Linda	B-Language
processes	O
are	O
decoupled	O
from	O
other	O
processes	O
,	O
communicating	O
only	O
through	O
the	O
tuplespace	B-Operating_System
;	O
a	O
process	O
need	O
have	O
no	O
notion	O
of	O
other	O
processes	O
except	O
for	O
the	O
kinds	O
of	O
tuples	B-Application
consumed	O
or	O
produced	O
.	O
</s>
<s>
Criticisms	O
of	O
Linda	B-Language
from	O
the	O
multiprocessing	O
community	O
tend	O
to	O
focus	O
on	O
the	O
decreased	O
speed	O
of	O
operations	O
in	O
Linda	B-Language
systems	O
as	O
compared	O
to	O
Message	B-Application
Passing	I-Application
Interface	I-Application
(	O
MPI	O
)	O
systems	O
.	O
</s>
<s>
Detailed	O
criticisms	O
of	O
the	O
Linda	B-Language
model	O
can	O
also	O
be	O
found	O
in	O
Steven	O
Ericsson-Zenith	O
'	O
s	O
book	O
Process	O
Interaction	O
Models	O
.	O
</s>
<s>
Many	O
of	O
these	O
researchers	O
proposed	O
larger	O
modifications	O
to	O
the	O
original	O
Linda	B-Language
model	O
,	O
developing	O
a	O
family	O
of	O
systems	O
known	O
as	O
Linda-like	B-Operating_System
systems	I-Operating_System
and	O
implemented	O
as	O
orthogonal	O
technology	O
(	O
unlike	O
original	O
version	O
)	O
.	O
</s>
<s>
An	O
example	O
of	O
this	O
is	O
the	O
language	O
Ease	B-Operating_System
designed	O
by	O
Steven	O
Ericsson-Zenith	O
.	O
</s>
<s>
Linda	B-Language
's	O
approach	O
has	O
also	O
been	O
compared	O
to	O
that	O
of	O
flow-based	B-Application
programming	I-Application
.	O
</s>
<s>
The	O
Linda-calculus	O
is	O
a	O
formalisation	O
of	O
the	O
above	O
model	O
with	O
the	O
difference	O
that	O
in	O
the	O
following	O
subsumes	O
both	O
out	O
and	O
eval	O
operations	O
.	O
</s>
<s>
We	O
abstract	O
the	O
concrete	O
representation	O
of	O
tuples	B-Application
.	O
</s>
<s>
we	O
are	O
allowed	O
to	O
form	O
and	O
apply	O
a	O
substitution	O
function	O
on	O
tuples	B-Application
substituting	O
variables	O
for	O
terms	O
that	O
yields	O
a	O
tuple	B-Application
.	O
</s>
<s>
The	O
Linda-calculus	O
processes	O
are	O
defined	O
by	O
the	O
following	O
grammar	O
.	O
</s>
<s>
The	O
syntax	O
includes	O
the	O
aftermentioned	O
Linda	B-Language
operations	O
,	O
non-deterministic	O
choice	O
,	O
and	O
recursion	O
.	O
</s>
<s>
A	O
tuple	B-Operating_System
space	I-Operating_System
is	O
represented	O
as	O
a	O
multiset	B-Language
of	O
the	O
processes	O
.	O
</s>
<s>
We	O
write	O
for	O
where	O
is	O
a	O
multiset	B-Language
,	O
a	O
singleton	O
multiset	B-Language
,	O
and	O
is	O
the	O
multiset	B-Language
union	O
operation	O
.	O
</s>
<s>
The	O
semantics	O
is	O
then	O
defined	O
as	O
a	O
reduction	O
relation	O
on	O
a	O
multiset	B-Language
as	O
follows	O
.	O
</s>
<s>
Note	O
that	O
(	O
input	O
)	O
consumes	O
the	O
tuple	B-Application
from	O
the	O
tuple	B-Operating_System
space	I-Operating_System
whereas	O
(	O
read	O
)	O
only	O
reads	O
it	O
.	O
</s>
<s>
Linda	B-Language
was	O
originally	O
implemented	O
in	O
C	B-Language
and	O
Fortran	B-Application
,	O
but	O
has	O
since	O
been	O
implemented	O
in	O
many	O
programming	O
languages	O
,	O
including	O
:	O
</s>
<s>
C	B-Language
:	O
C-Linda	O
,	O
,	O
</s>
<s>
C++	B-Language
:	O
,	O
</s>
<s>
C#	B-Application
:	O
</s>
<s>
Erlang	B-Operating_System
:	O
</s>
<s>
Go	B-Application
:	O
</s>
<s>
Java	B-Language
:	O
JavaSpaces	B-Operating_System
,	O
,	O
,	O
,	O
,	O
</s>
<s>
JavaScript	B-Language
:	O
</s>
<s>
Lua	B-Language
:	O
</s>
<s>
Prolog	B-Language
:	O
</s>
<s>
Swift	B-Application
:	O
</s>
<s>
Some	O
of	O
the	O
more	O
notable	O
Linda	B-Language
implementations	O
include	O
:	O
</s>
<s>
C-Linda	O
or	O
TCP-Linda	O
-	O
the	O
earliest	O
commercial	O
and	O
a	O
widespread	O
implementation	O
of	O
virtual	O
shared	O
memory	O
for	O
supercomputers	O
and	O
clustered	O
systems	O
from	O
Scientific	O
Computing	O
Associates	O
,	O
founded	O
by	O
Martin	O
Schultz	O
.	O
</s>
<s>
JavaSpaces	B-Operating_System
-	O
a	O
Java-based	O
tuplespace	B-Operating_System
implementation	O
that	O
helped	O
popularize	O
distributed	O
computing	O
.	O
</s>
<s>
-	O
a	O
Java-based	O
tuplespace	B-Operating_System
platform	O
from	O
IBM	O
.	O
</s>
