<s>
An	O
Xlet	B-Language
is	O
very	O
similar	O
to	O
a	O
Java	B-Application
applet	I-Application
and	O
is	O
originally	O
introduced	O
in	O
Sun	O
Microsystems	O
's	O
Java	B-Language
TV	I-Language
specification	O
to	O
support	O
applications	O
for	O
Digital	B-Application
TV	I-Application
.	O
</s>
<s>
Though	O
Xlet	B-Language
looks	O
superficially	O
different	O
from	O
other	O
application	O
models	O
in	O
Java	O
such	O
as	O
applet	O
and	O
MIDlet	B-Language
,	O
it	O
is	O
actually	O
meant	O
to	O
be	O
a	O
generalization	O
of	O
such	O
models	O
.	O
</s>
<s>
The	O
X	O
in	O
Xlet	B-Language
means	O
an	O
unknown	O
,	O
meaning	O
that	O
the	O
Xlet	B-Language
framework	O
may	O
be	O
used	O
in	O
any	O
context	O
rather	O
than	O
specific	O
to	O
Digital	B-Application
TV	I-Application
.	O
</s>
<s>
Accordingly	O
,	O
Xlet	B-Language
was	O
later	O
re-introduced	O
as	O
a	O
part	O
of	O
the	O
Personal	O
Basis	O
Profile	O
in	O
the	O
package	O
,	O
which	O
is	O
slightly	O
different	O
from	O
the	O
original	O
design	O
in	O
the	O
Java	B-Language
TV	I-Language
specification	O
.	O
</s>
<s>
The	O
Xlet	B-Language
provision	O
of	O
a	O
pause/resume	O
feature	O
is	O
essential	O
for	O
a	O
set-top	O
box	O
(	O
STB	O
)	O
environment	O
,	O
which	O
has	O
limited	O
memory	O
resources	O
and	O
restrictions	O
on	O
bandwidth	O
from	O
the	O
head-end	O
provider	O
.	O
</s>
<s>
The	O
current	O
practice	O
and	O
intent	O
of	O
the	O
Xlet	B-Language
framework	O
is	O
to	O
provide	O
downloadable	O
applications	O
for	O
Personal	O
Basis	O
Profile	O
(	O
PBP	O
)	O
platforms	O
.	O
</s>
<s>
In	O
particular	O
,	O
the	O
BD-J	B-Language
platform	O
uses	O
Xlets	B-Language
as	O
its	O
programming	O
framework	O
.	O
</s>
<s>
While	O
Sun	O
has	O
provided	O
a	O
Java	B-Language
TV	I-Language
reference	O
implementation	O
within	O
which	O
they	O
provide	O
a	O
simple	O
Xlet	B-Language
runner	O
called	O
RunXlet	O
,	O
at	O
least	O
one	O
other	O
open-source	O
effort	O
to	O
implement	O
an	O
Xlet	B-Language
run	O
has	O
been	O
made	O
.	O
</s>
<s>
The	O
interface	O
for	O
an	O
Xlet	B-Language
is	O
defined	O
in	O
the	O
javax.tv.xlet	O
package	O
:	O
</s>
