<s>
A	O
KDL	B-Operating_System
(	O
short	O
for	O
Kernel	B-Operating_System
Debug(ger )	O
Land	O
)	O
is	O
a	O
term	O
used	O
on	O
BeOS/Haiku	O
and	O
possibly	O
other	O
operating	B-General_Concept
systems	I-General_Concept
for	O
a	O
serious	O
kernel	B-Operating_System
error	O
which	O
causes	O
the	O
computer	O
to	O
drop	O
into	O
the	O
kernel	B-Operating_System
debugger	I-Operating_System
.	O
</s>
<s>
While	O
a	O
KDL	B-Operating_System
brought	O
about	O
by	O
a	O
buggy	O
driver	O
which	O
is	O
not	O
crucial	O
,	O
such	O
as	O
a	O
filesystem	B-Application
driver	O
,	O
can	O
be	O
escaped	O
from	O
(	O
with	O
the	O
command	O
'	O
es	O
 '	O
)	O
,	O
it	O
usually	O
leaves	O
the	O
user	O
needing	O
to	O
reboot	O
.	O
</s>
<s>
The	O
Kernel	B-Operating_System
Debug(ger )	O
Land	O
can	O
also	O
be	O
entered	O
on	O
BeOS/Haiku	O
at	O
any	O
time	O
by	O
pressing	O
Alt-SysReq-D	O
on	O
the	O
keyboard	O
while	O
the	O
system	O
is	O
running	O
.	O
</s>
