<s>
SAIL	B-Language
,	O
the	O
Stanford	B-Language
Artificial	I-Language
Intelligence	I-Language
Language	I-Language
,	O
was	O
developed	O
by	O
Dan	O
Swinehart	O
and	O
Bob	O
Sproull	O
of	O
the	O
Stanford	O
AI	O
Lab	O
in	O
1970	O
.	O
</s>
<s>
It	O
was	O
originally	O
a	O
large	O
ALGOL	O
60-like	O
language	O
for	O
the	O
PDP-10	B-Device
and	O
DECSYSTEM-20	B-Device
.	O
</s>
<s>
SAIL	B-Language
's	O
main	O
feature	O
is	O
a	O
symbolic	O
data	O
system	O
based	O
upon	O
an	O
associative	O
store	O
(	O
based	O
on	O
the	O
LEAP	B-Language
system	I-Language
of	O
Jerry	O
Feldman	O
and	O
Paul	O
Rovner	O
)	O
.	O
</s>
<s>
Other	O
features	O
include	O
processes	O
,	O
events	O
and	O
interrupts	O
,	O
contexts	O
,	O
backtracking	B-Algorithm
and	O
record	O
garbage	O
collection	O
.	O
</s>
<s>
A	O
number	O
of	O
interesting	O
software	O
systems	O
were	O
coded	O
in	O
SAIL	B-Language
,	O
including	O
some	O
early	O
versions	O
of	O
FTP	B-Protocol
and	O
TeX	B-Application
,	O
a	O
document	O
formatting	O
system	O
called	O
PUB	O
,	O
and	O
BRIGHT	O
,	O
a	O
clinical	O
database	O
project	O
sponsored	O
by	O
the	O
National	O
Institutes	O
of	O
Health	O
.	O
</s>
<s>
In	O
1978	O
,	O
there	O
were	O
half	O
a	O
dozen	O
different	O
operating	O
systems	O
for	O
the	O
PDP-10	B-Device
:	O
ITS	B-Application
(	O
MIT	O
)	O
,	O
WAITS	B-Application
(	O
Stanford	O
)	O
,	O
TOPS-10	B-Operating_System
(	O
DEC	O
)	O
,	O
CMU	O
TOPS-10	B-Operating_System
(	O
Carnegie	O
Mellon	O
)	O
,	O
TENEX	B-Operating_System
(	O
BBN	O
)	O
,	O
Tymcom-X	O
(	O
Tymshare	O
)	O
,	O
and	O
TOPS-20	B-Operating_System
(	O
DEC	O
,	O
based	O
on	O
TENEX	B-Operating_System
)	O
.	O
</s>
<s>
SAIL	B-Language
was	O
ported	O
from	O
WAITS	B-Application
to	O
ITS	B-Application
so	O
that	O
MIT	O
researchers	O
could	O
make	O
use	O
of	O
software	O
developed	O
at	O
Stanford	O
University	O
.	O
</s>
<s>
A	O
machine-independent	O
version	O
of	O
SAIL	B-Language
called	O
MAINSAIL	O
was	O
developed	O
in	O
the	O
late	O
1970s	O
and	O
was	O
used	O
to	O
develop	O
many	O
eCAD	O
design	O
tools	O
during	O
the	O
1980s	O
.	O
</s>
