<s>
Linda-like	B-Operating_System
systems	I-Operating_System
are	O
parallel	B-Application
and	O
distributed	B-Architecture
programming	I-Architecture
models	O
that	O
use	O
unstructured	B-Application
collections	O
of	O
tuples	B-Application
as	O
a	O
communication	O
mechanism	O
between	O
different	O
processes	O
.	O
</s>
<s>
In	O
addition	O
to	O
proper	O
Linda	B-Language
implementations	O
,	O
these	O
include	O
other	O
systems	O
such	O
as	O
the	O
following	O
:	O
</s>
<s>
Intel	B-Operating_System
Concurrent	I-Operating_System
Collections	I-Operating_System
(	O
CnC	O
)	O
is	O
a	O
programming	O
model	O
based	O
on	O
"	O
item	O
collections	O
"	O
which	O
resemble	O
tuple	B-Application
spaces	O
,	O
but	O
are	O
single	O
assignment	O
(	O
tuples	B-Application
may	O
not	O
be	O
removed	O
or	O
replaced	O
)	O
.	O
</s>
<s>
Because	O
of	O
this	O
restriction	O
Concurrent	B-Operating_System
Collections	I-Operating_System
has	O
a	O
deterministic	O
execution	O
semantics	O
,	O
but	O
has	O
difficulties	O
with	O
storage	O
deallocation	O
.	O
</s>
