<s>
Macintosh	B-Language
Common	I-Language
Lisp	I-Language
(	O
MCL	O
)	O
is	O
an	O
implementation	O
and	O
IDE	B-Application
for	O
the	O
Common	B-Language
Lisp	I-Language
programming	I-Language
language	I-Language
.	O
</s>
<s>
Various	O
versions	O
of	O
MCL	O
run	O
under	O
the	O
classic	B-Application
Mac	I-Application
OS	I-Application
(	O
m68k	O
and	O
PPC	O
)	O
and	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
.	O
</s>
<s>
RMCL	O
is	O
based	O
on	O
MCL	O
5.1	O
and	O
does	O
run	O
under	O
Rosetta	B-Operating_System
on	O
Intel-based	O
Macs	O
.	O
</s>
<s>
MCL	O
was	O
famous	O
for	O
its	O
integration	O
with	O
the	O
Macintosh	O
toolbox	O
(	O
later	O
:	O
Apple	B-Operating_System
Carbon	I-Operating_System
)	O
,	O
which	O
allowed	O
direct	O
access	O
to	O
most	O
of	O
the	O
Mac	B-Application
OS	I-Application
functionality	O
directly	O
from	O
Lisp	O
.	O
</s>
<s>
This	O
was	O
achieved	O
with	O
a	O
low-level	O
interface	O
that	O
allowed	O
direct	O
manipulation	O
of	O
native	O
Mac	B-Application
OS	I-Application
data	O
structures	O
from	O
Lisp	O
,	O
together	O
with	O
a	O
high-level	O
interface	O
that	O
was	O
more	O
convenient	O
to	O
use	O
.	O
</s>
<s>
In	O
a	O
2001	O
article	O
in	O
Dr.	O
Dobb	O
's	O
Journal	O
,	O
Peter	O
Norvig	O
wrote	O
that	O
"	O
MCL	O
is	O
my	O
favorite	O
IDE	B-Application
on	O
the	O
Macintosh	O
platform	O
for	O
any	O
language	O
and	O
is	O
a	O
serious	O
rival	O
to	O
those	O
on	O
other	O
platforms	O
"	O
.	O
</s>
<s>
In	O
2009	O
RMCL	O
(	O
MCL	O
running	O
under	O
Rosetta	B-Operating_System
)	O
was	O
published	O
as	O
open	O
source	O
.	O
</s>
<s>
This	O
version	O
runs	O
under	O
Rosetta	B-Operating_System
(	O
Apple	O
's	O
PPC	O
to	O
Intel	O
code	O
translator	O
that	O
is	O
an	O
optional	O
install	O
under	O
Mac	O
OS	O
X	O
10.6	O
)	O
.	O
</s>
