<s>
sysjail	B-Device
is	O
a	O
defunct	O
user-land	O
virtualiser	O
for	O
systems	O
supporting	O
the	O
systrace	B-Application
library	O
-	O
as	O
of	O
version	O
1.0	O
limited	O
to	O
OpenBSD	B-Operating_System
,	O
NetBSD	B-Device
and	O
MirOS	B-Application
.	O
</s>
<s>
Its	O
original	O
design	O
was	O
inspired	O
by	O
FreeBSD	B-Language
jail	I-Language
,	O
a	O
similar	O
utility	O
(	O
although	O
part	O
of	O
the	O
kernel	O
)	O
for	O
FreeBSD	B-Operating_System
.	O
</s>
<s>
sysjail	B-Device
was	O
developed	O
and	O
released	O
in	O
2006	O
by	O
Kristaps	O
Dzonsons	O
(	O
aka	O
Johnson	O
)	O
,	O
a	O
research	O
assistant	O
in	O
Game	O
theory	O
at	O
the	O
Stockholm	O
School	O
of	O
Economics	O
,	O
and	O
Maikls	O
Deksters	O
.	O
</s>
<s>
sysjail	B-Device
was	O
re-written	O
from	O
scratch	O
in	O
2007	O
to	O
support	O
emulated	O
processes	O
in	O
jails	O
,	O
limited	O
(	O
initially	O
)	O
to	O
Linux	B-Application
emulation	O
.	O
</s>
<s>
The	O
restrictions	O
of	O
sysjail	B-Device
could	O
be	O
evaded	O
by	O
exploiting	O
race	B-Operating_System
conditions	I-Operating_System
between	O
the	O
wrapper	O
's	O
security	O
checks	O
and	O
kernel	O
's	O
execution	O
of	O
the	O
syscalls	O
.	O
</s>
