<s>
NuKernel	B-Operating_System
is	O
a	O
microkernel	B-Operating_System
which	O
was	O
developed	O
at	O
Apple	O
Computer	O
during	O
the	O
early	O
1990s	O
.	O
</s>
<s>
Written	O
from	O
scratch	O
and	O
designed	O
using	O
concepts	O
from	O
the	O
Mach	B-Operating_System
3.0	I-Operating_System
microkernel	B-Operating_System
,	O
with	O
extensive	O
additions	O
for	O
soft	O
real-time	B-General_Concept
scheduling	O
to	O
improve	O
multimedia	O
performance	O
,	O
it	O
was	O
the	O
basis	O
for	O
the	O
Copland	B-Application
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Only	O
one	O
NuKernel	B-Operating_System
version	O
was	O
released	O
,	O
with	O
a	O
Copland	B-Application
alpha	O
release	O
.	O
</s>
<s>
Development	O
ended	O
in	O
1996	O
with	O
the	O
cancellation	O
of	O
Copland	B-Application
.	O
</s>
<s>
The	O
External	O
Reference	O
Specification	O
(	O
ERS	O
)	O
for	O
NuKernel	B-Operating_System
is	O
contained	O
in	O
its	O
entirety	O
in	O
its	O
patent	O
.	O
</s>
<s>
The	O
one-time	O
technical	O
lead	O
for	O
NuKernel	B-Operating_System
,	O
Jeff	O
Robbin	O
,	O
was	O
one	O
of	O
the	O
leaders	O
of	O
iTunes	B-Operating_System
and	O
the	B-Device
iPod	I-Device
.	O
</s>
<s>
Apple	O
's	O
NuKernel	B-Operating_System
is	O
not	O
the	O
microkernel	B-Operating_System
in	O
BeOS	B-Application
,	O
nukernel	B-Operating_System
.	O
</s>
