<s>
A	O
supervisory	B-Operating_System
program	I-Operating_System
or	O
supervisor	O
is	O
a	O
computer	B-Application
program	I-Application
,	O
usually	O
part	O
of	O
an	O
operating	B-General_Concept
system	I-General_Concept
,	O
that	O
controls	O
the	O
execution	O
of	O
other	O
routines	O
and	O
regulates	O
work	O
scheduling	O
,	O
input/output	B-General_Concept
operations	O
,	O
error	B-General_Concept
actions	I-General_Concept
,	O
and	O
similar	O
functions	O
and	O
regulates	O
the	O
flow	O
of	O
work	O
in	O
a	O
data	B-General_Concept
processing	I-General_Concept
system	O
.	O
</s>
<s>
It	O
can	O
also	O
refer	O
to	O
a	O
program	O
that	O
allocates	O
computer	O
component	O
space	O
and	O
schedules	O
computer	O
events	O
by	O
task	B-Application
queuing	I-Application
and	O
system	O
interrupts	B-Application
.	O
</s>
<s>
Control	O
of	O
the	O
system	O
is	O
returned	O
to	O
the	O
supervisory	B-Operating_System
program	I-Operating_System
frequently	O
enough	O
to	O
ensure	O
that	O
demands	O
on	O
the	O
system	O
are	O
met	O
.	O
</s>
<s>
Historically	O
,	O
this	O
term	O
was	O
essentially	O
associated	O
with	O
IBM	O
's	O
line	O
of	O
mainframe	B-Architecture
operating	B-General_Concept
systems	I-General_Concept
starting	O
with	O
OS/360	B-Application
.	O
</s>
<s>
In	O
other	O
operating	B-General_Concept
systems	I-General_Concept
,	O
the	O
supervisor	O
is	O
generally	O
called	O
the	O
kernel	B-Operating_System
.	O
</s>
<s>
In	O
the	O
1970s	O
,	O
IBM	O
further	O
abstracted	O
the	O
supervisor	O
state	B-Application
from	O
the	O
hardware	O
,	O
resulting	O
in	O
a	O
hypervisor	B-Operating_System
that	O
enabled	O
full	B-Architecture
virtualization	I-Architecture
,	O
i.e.	O
</s>
<s>
the	O
capacity	O
to	O
run	O
multiple	O
operating	B-General_Concept
systems	I-General_Concept
on	O
the	O
same	O
machine	O
totally	O
independently	O
from	O
each	O
other	O
.	O
</s>
<s>
Hence	O
the	O
first	O
such	O
system	O
was	O
called	O
Virtual	O
Machine	O
or	O
VM	B-Application
.	O
</s>
