<s>
In	O
the	O
field	O
of	O
digital	O
and	O
interactive	O
television	O
,	O
Nested	B-Device
Context	I-Device
Language	I-Device
(	O
NCL	O
)	O
is	O
a	O
declarative	B-Language
authoring	I-Language
language	I-Language
for	O
hypermedia	O
documents	O
.	O
</s>
<s>
NCL	O
is	O
an	O
XML	B-Protocol
application	O
language	O
that	O
is	O
an	O
extension	O
of	O
XHTML	B-Language
,	O
with	O
XML	B-Protocol
elements	O
and	O
attributes	O
specified	O
by	O
a	O
modular	O
approach	O
.	O
</s>
<s>
NCL	O
modules	O
can	O
be	O
added	O
to	O
standard	O
web	O
languages	O
,	O
such	O
as	O
XLink	O
and	O
SMIL	B-Language
.	O
</s>
<s>
NCL	O
was	O
initially	O
designed	O
for	O
the	O
Web	O
environment	O
,	O
but	O
a	O
major	O
application	O
of	O
NCL	O
is	O
use	O
as	O
the	O
declarative	B-Language
language	I-Language
of	O
the	O
Japanese-Brazilian	O
ISDB-Tb	B-Application
(	O
International	O
Standard	O
for	O
Digital	O
Broadcasting	O
)	O
terrestrial	O
DTV	O
digital	B-Application
television	I-Application
middleware	B-General_Concept
(	O
named	O
Ginga	B-Application
)	O
.	O
</s>
<s>
In	O
both	O
cases	O
it	O
is	O
used	O
to	O
develop	O
interactive	O
applications	O
to	O
digital	B-Application
television	I-Application
.	O
</s>
<s>
Each	O
module	O
in	O
turn	O
defines	O
one	O
or	O
more	O
XML	B-Protocol
elements	O
.	O
</s>
