<s>
Java	B-Language
Application	I-Language
Descriptor	I-Language
(	O
JAD	B-Language
)	O
files	O
describe	O
the	O
MIDlets	B-Language
(	O
Java	B-Language
ME	I-Language
applications	O
)	O
that	O
are	O
distributed	O
as	O
JAR	B-Language
files	I-Language
.	O
</s>
<s>
JAD	B-Language
files	O
are	O
commonly	O
used	O
to	O
package	O
Java	B-Language
applications	O
or	O
games	O
that	O
can	O
be	O
downloaded	O
to	O
mobile	O
phones	O
.	O
</s>
<s>
Java	B-Language
applications	O
enable	O
mobile	O
phones	O
to	O
interact	O
functionally	O
with	O
online	O
web	O
services	O
,	O
such	O
as	O
the	O
ability	O
to	O
send	O
SMS	B-Device
messages	O
via	O
GSM	O
mobile	O
Internet	O
or	O
interact	O
in	O
multiplayer	O
games	O
.	O
</s>
<s>
Some	O
BlackBerry	B-Operating_System
devices	O
use	O
JAD	B-Language
files	O
for	O
themes	O
,	O
while	O
on	O
some	O
mobile	O
phones	O
without	O
memory	O
cards	O
it	O
is	O
not	O
possible	O
to	O
download	O
any	O
apps	O
.	O
</s>
<s>
Recent	O
midlets	B-Language
contain	O
a	O
manifest	O
file	O
in	O
the	O
JAR	B-Language
archive	I-Language
.	O
</s>
<s>
This	O
file	O
contains	O
much	O
of	O
the	O
information	O
stored	O
in	O
the	O
JAD	B-Language
file	O
,	O
rendering	O
it	O
unnecessary	O
in	O
most	O
cases	O
.	O
</s>
<s>
The	O
MIDP2	B-Language
specification	O
instructs	O
that	O
web	O
servers	O
should	O
serve	O
JAD	B-Language
files	O
with	O
a	O
MIME	B-Application
type	I-Application
of	O
""	O
.	O
</s>
<s>
If	O
this	O
MIME	B-Application
type	I-Application
is	O
not	O
correctly	O
configured	O
,	O
many	O
phones	O
will	O
fail	O
to	O
install	O
the	O
MIDlet	B-Language
.	O
</s>
