<s>
Actor-Based	B-Language
Concurrent	I-Language
Language	I-Language
(	O
ABCL	O
)	O
is	O
a	O
family	O
of	O
programming	O
languages	O
,	O
developed	O
in	O
Japan	O
in	O
the	O
1980s	O
and	O
1990s	O
.	O
</s>
<s>
ABCL/1	B-Language
(	O
Actor-Based	B-Language
Concurrent	I-Language
Language	I-Language
)	O
is	O
a	O
prototype-based	B-Application
concurrent	O
programming	O
language	O
for	O
the	O
ABCL	O
MIMD	O
system	O
,	O
created	O
in	O
1986	O
by	O
Akinori	O
Yonezawa	O
,	O
of	O
the	O
Department	O
of	O
Information	O
Science	O
at	O
the	O
University	O
of	O
Tokyo	O
.	O
</s>
<s>
ABCL/1	B-Language
uses	O
asynchronous	O
message	B-Architecture
passing	I-Architecture
among	O
objects	O
to	O
achieve	O
concurrency	O
.	O
</s>
<s>
It	O
requires	O
Common	B-Language
Lisp	I-Language
.	O
</s>
<s>
Implementations	O
in	O
Kyoto	B-Language
Common	I-Language
Lisp	I-Language
(	O
KCL	O
)	O
and	O
Symbolics	O
Lisp	O
are	O
available	O
from	O
the	O
author	O
.	O
</s>
<s>
An	O
implementation	O
of	O
ABCL/c	B-Language
+	I-Language
is	O
available	O
from	O
the	O
ACM	O
.	O
</s>
<s>
ABCL/R	B-Language
is	O
an	O
object-oriented	B-Language
reflective	B-Language
subset	O
of	O
ABCL/1	B-Language
,	O
written	O
by	O
Professor	O
Akinori	O
Yonezawa	O
of	O
Tokyo	O
Institute	O
of	O
Technology	O
in	O
1988	O
.	O
</s>
<s>
ABCL/R2	B-Language
is	O
a	O
second	O
generation	O
version	O
of	O
ABCL/R	B-Language
,	O
designed	O
for	O
the	O
Hybrid	O
Group	O
Architecture	O
.	O
</s>
<s>
It	O
was	O
produced	O
at	O
the	O
Tokyo	O
Institute	O
of	O
Technology	O
in	O
1992	O
,	O
and	O
has	O
almost	O
all	O
the	O
functionality	O
of	O
ABCL/1	B-Language
.	O
</s>
<s>
It	O
is	O
written	O
in	O
Common	B-Language
Lisp	I-Language
.	O
</s>
<s>
As	O
a	O
reflective	B-Language
language	O
,	O
its	O
programs	O
can	O
dynamically	O
control	O
their	O
behavior	O
,	O
including	O
scheduling	O
policy	O
,	O
from	O
within	O
a	O
user-process	O
context	O
.	O
</s>
