<s>
A	O
language-based	B-Operating_System
system	I-Operating_System
is	O
a	O
type	O
of	O
operating	B-General_Concept
system	I-General_Concept
that	O
uses	O
language	O
features	O
to	O
provide	O
security	O
,	O
instead	O
of	O
or	O
in	O
addition	O
to	O
hardware	O
mechanisms	O
.	O
</s>
<s>
In	O
such	O
systems	O
,	O
code	O
referred	O
to	O
as	O
the	O
trusted	O
base	O
is	O
responsible	O
for	O
approving	O
programs	O
for	O
execution	B-General_Concept
,	O
assuring	O
they	O
cannot	O
perform	O
operations	O
detrimental	O
to	O
the	O
system	O
's	O
stability	O
without	O
first	O
being	O
detected	O
and	O
dealt	O
with	O
.	O
</s>
<s>
A	O
very	O
common	O
strategy	O
of	O
guaranteeing	O
that	O
such	O
operations	O
are	O
impossible	O
is	O
to	O
base	O
the	O
system	O
around	O
a	O
high-level	B-Language
language	I-Language
,	O
such	O
as	O
Java	B-Language
,	O
whose	O
design	O
precludes	O
dangerous	O
constructs	O
;	O
many	O
are	O
entirely	O
written	O
in	O
such	O
a	O
language	O
,	O
with	O
only	O
the	O
minimum	O
amount	O
of	O
low-level	B-Language
code	I-Language
being	O
used	O
.	O
</s>
<s>
Since	O
language-based	B-Operating_System
systems	I-Operating_System
can	O
assure	O
ahead	O
of	O
time	O
that	O
they	O
cannot	O
do	O
things	O
that	O
can	O
damage	O
the	O
system	O
(	O
such	O
as	O
corrupting	O
memory	O
by	O
dereferencing	O
dangling	B-Error_Name
pointers	I-Error_Name
)	O
,	O
it	O
is	O
possible	O
for	O
them	O
to	O
avoid	O
expensive	O
address	O
space	O
switches	O
needed	O
by	O
traditional	O
OSes	O
;	O
because	O
of	O
this	O
,	O
microkernels	B-Operating_System
are	O
more	O
popular	O
than	O
traditional	O
systems	O
.	O
</s>
<s>
A	O
more	O
extreme	O
form	O
of	O
this	O
is	O
a	O
high-level	B-Architecture
language	I-Architecture
computer	I-Architecture
architecture	I-Architecture
,	O
where	O
the	O
trusted	O
base	O
is	O
pushed	O
into	O
hardware	O
,	O
and	O
the	O
entire	O
system	O
is	O
written	O
in	O
a	O
high-level	B-Language
language	I-Language
.	O
</s>
