<s>
The	O
iOS	B-Operating_System
SDK	I-Operating_System
(	O
iOS	B-Operating_System
Software	I-Operating_System
Development	I-Operating_System
Kit	I-Operating_System
)	O
,	O
formerly	O
the	O
iPhone	B-Operating_System
SDK	I-Operating_System
,	O
is	O
a	O
software	B-Application
development	I-Application
kit	I-Application
(	O
SDK	O
)	O
developed	O
by	O
Apple	O
Inc	O
.	O
</s>
<s>
The	O
kit	O
allows	O
for	O
the	O
development	O
of	O
mobile	B-Application
apps	I-Application
on	O
Apple	O
's	O
iOS	B-Application
and	O
iPadOS	B-Operating_System
operating	O
systems	O
.	O
</s>
<s>
The	O
iOS	B-Operating_System
SDK	I-Operating_System
is	O
a	O
free	O
download	O
for	O
users	O
of	O
Macintosh	B-Device
(	O
or	O
Mac	B-Device
)	O
personal	O
computers	O
.	O
</s>
<s>
It	O
is	O
not	O
available	O
for	O
Microsoft	B-Application
Windows	I-Application
PCs	O
.	O
</s>
<s>
The	O
SDK	O
contains	O
sets	O
giving	O
developers	O
access	O
to	O
various	O
functions	O
and	O
services	O
of	O
iOS	B-Application
devices	O
,	O
such	O
as	O
hardware	B-Architecture
and	O
software	O
attributes	O
.	O
</s>
<s>
It	O
also	O
contains	O
an	O
iPhone	B-Operating_System
simulator	I-Operating_System
to	O
mimic	O
the	O
look	O
and	O
feel	O
of	O
the	O
device	O
on	O
the	O
computer	O
while	O
developing	O
.	O
</s>
<s>
New	O
versions	O
of	O
the	O
SDK	O
accompany	O
new	O
versions	O
of	O
iOS	B-Application
.	O
</s>
<s>
In	O
order	O
to	O
test	O
applications	O
,	O
get	O
technical	O
support	O
,	O
and	O
distribute	O
apps	O
through	O
App	B-Application
Store	I-Application
,	O
developers	O
are	O
required	O
to	O
subscribe	O
to	O
the	O
Apple	B-Operating_System
Developer	I-Operating_System
Program	I-Operating_System
.	O
</s>
<s>
Combined	O
with	O
Xcode	B-Operating_System
,	O
the	O
iOS	B-Operating_System
SDK	I-Operating_System
helps	O
developers	O
write	O
iOS	B-Application
apps	I-Application
using	O
officially	O
supported	O
programming	O
languages	O
,	O
including	O
Swift	B-Application
and	O
Objective-C	B-Language
.	O
Other	O
companies	O
have	O
also	O
created	O
tools	O
that	O
allow	O
for	O
the	O
development	O
of	O
native	O
iOS	B-Application
apps	I-Application
using	O
their	O
respective	O
programming	O
languages	O
.	O
</s>
<s>
While	O
originally	O
developing	O
iPhone	B-Device
prior	O
to	O
its	O
unveiling	O
in	O
2007	O
,	O
Apple	O
's	O
then-CEO	O
Steve	O
Jobs	O
did	O
not	O
intend	O
to	O
let	O
third-party	O
developers	O
build	O
native	O
apps	O
for	O
the	O
iOS	B-Application
operating	O
system	O
,	O
instead	O
directing	O
them	O
to	O
make	O
web	B-Application
applications	I-Application
for	O
the	O
Safari	B-Application
web	I-Application
browser	I-Application
.	O
</s>
<s>
However	O
,	O
backlash	O
from	O
developers	O
prompted	O
the	O
company	O
to	O
reconsider	O
,	O
with	O
Jobs	O
announcing	O
on	O
October	O
17	O
,	O
2007	O
,	O
that	O
Apple	O
would	O
have	O
a	O
software	B-Application
development	I-Application
kit	I-Application
(	O
SDK	O
)	O
available	O
for	O
developers	O
by	O
February	O
2008	O
.	O
</s>
<s>
The	O
iOS	B-Operating_System
SDK	I-Operating_System
is	O
a	O
free	O
download	O
for	O
Mac	B-Device
users	O
.	O
</s>
<s>
It	O
is	O
not	O
available	O
for	O
Microsoft	B-Application
Windows	I-Application
personal	O
computers	O
.	O
</s>
<s>
To	O
test	O
the	O
application	O
,	O
get	O
technical	O
support	O
,	O
and	O
distribute	O
applications	O
through	O
App	B-Application
Store	I-Application
,	O
developers	O
are	O
required	O
to	O
subscribe	O
to	O
the	O
Apple	B-Operating_System
Developer	I-Operating_System
Program	I-Operating_System
.	O
</s>
<s>
The	O
SDK	O
also	O
contains	O
an	O
iPhone	B-Operating_System
simulator	I-Operating_System
,	O
a	O
program	O
used	O
to	O
simulate	O
the	O
look	O
and	O
feel	O
of	O
iPhone	B-Device
on	O
the	O
developer	O
's	O
computer	O
.	O
</s>
<s>
New	O
SDK	O
versions	O
accompany	O
new	O
iOS	B-Application
versions	O
.	O
</s>
<s>
The	O
iOS	B-Operating_System
SDK	I-Operating_System
,	O
combined	O
with	O
Xcode	B-Operating_System
,	O
helps	O
developers	O
write	O
iOS	B-Application
applications	I-Application
using	O
officially	O
supported	O
programming	O
languages	O
,	O
including	O
Swift	B-Application
and	O
Objective-C	B-Language
.	O
</s>
<s>
An	O
.ipa	O
(	O
iOS	B-Application
App	I-Application
Store	I-Application
Package	O
)	O
file	O
is	O
an	O
iOS	B-Application
application	I-Application
archive	O
file	O
which	O
stores	O
an	O
iOS	B-Application
app	I-Application
.	O
</s>
<s>
In	O
2008	O
,	O
Sun	O
Microsystems	O
announced	O
plans	O
to	O
release	O
a	O
Java	B-Language
Virtual	I-Language
Machine	I-Language
(	O
JVM	B-Language
)	O
for	O
iOS	B-Application
,	O
based	O
on	O
the	O
Java	B-Language
Platform	I-Language
,	I-Language
Micro	I-Language
Edition	I-Language
version	O
of	O
Java	O
.	O
</s>
<s>
This	O
would	O
enable	O
Java	O
applications	O
to	O
run	O
on	O
iPhone	B-Device
and	O
iPod	O
Touch	O
.	O
</s>
<s>
Sun	O
also	O
worked	O
with	O
a	O
third-party	O
company	O
called	O
Innaworks	O
in	O
attempts	O
to	O
get	O
Java	O
on	O
iPhone	B-Device
.	O
</s>
<s>
Despite	O
the	O
apparent	O
lack	O
of	O
interest	O
from	O
Apple	O
,	O
a	O
firmware	B-Application
leak	O
of	O
the	O
2007	O
iPhone	B-Device
release	O
revealed	O
an	O
ARM	B-Architecture
chip	I-Architecture
with	O
a	O
processor	O
with	O
Jazelle	B-Language
support	O
for	O
embedded	O
Java	O
execution	O
.	O
</s>
<s>
Novell	O
announced	O
in	O
September	O
2009	O
that	O
they	O
had	O
successfully	O
developed	O
MonoTouch	B-Application
,	O
a	O
software	B-Architecture
framework	I-Architecture
that	O
let	O
developers	O
write	O
native	O
iPhone	B-Application
applications	I-Application
in	O
the	O
C#	B-Application
and	O
.NET	B-Application
programming	O
languages	O
,	O
while	O
still	O
maintaining	O
compatibility	O
with	O
Apple	O
's	O
requirements	O
.	O
</s>
<s>
iOS	B-Application
does	O
not	O
support	O
Adobe	B-Operating_System
Flash	I-Operating_System
,	O
and	O
although	O
Adobe	O
has	O
two	O
versions	O
of	O
its	O
software	O
:	O
Flash	O
and	O
Flash	O
Lite	O
,	O
Apple	O
views	O
neither	O
as	O
suitable	O
for	O
the	O
iPhone	B-Device
,	O
claiming	O
that	O
full	O
Flash	O
is	O
"	O
too	O
slow	O
to	O
be	O
useful	O
"	O
,	O
and	O
Flash	O
Lite	O
to	O
be	O
"	O
not	O
capable	O
of	O
being	O
used	O
with	O
the	O
Web	O
"	O
.	O
</s>
<s>
In	O
October	O
2009	O
,	O
Adobe	O
announced	O
that	O
an	O
upcoming	O
update	O
to	O
its	O
Creative	B-Operating_System
Suite	I-Operating_System
would	O
feature	O
a	O
component	O
to	O
let	O
developers	O
build	O
native	O
iPhone	B-Application
apps	I-Application
using	O
the	O
company	O
's	O
Flash	O
development	O
tools	O
.	O
</s>
<s>
The	O
software	O
was	O
officially	O
released	O
as	O
part	O
of	O
the	O
company	O
's	O
Creative	B-Operating_System
Suite	I-Operating_System
5	O
collection	O
of	O
professional	O
applications	O
.	O
</s>
<s>
In	O
April	O
2010	O
,	O
Apple	O
made	O
controversial	O
changes	O
to	O
its	O
iPhone	B-Device
Developer	O
Agreement	O
,	O
requiring	O
developers	O
to	O
use	O
only	O
"	O
approved	O
"	O
programming	O
languages	O
in	O
order	O
to	O
publish	O
apps	O
on	O
App	B-Application
Store	I-Application
,	O
and	O
banning	O
applications	O
that	O
used	O
third-party	O
development	O
tools	O
.	O
</s>
<s>
Originally	O
called	O
"	O
Project	O
Marzipan	O
"	O
,	O
Mac	B-Device
Catalyst	O
helps	O
developers	O
bring	O
iPadOS	B-Operating_System
app	O
experiences	O
to	O
macOS	B-Application
,	O
and	O
make	O
it	O
easier	O
to	O
take	O
apps	O
developed	O
for	O
iPadOS	B-Operating_System
devices	O
to	O
Macs	O
by	O
avoiding	O
the	O
need	O
to	O
write	O
the	O
underlying	O
software	O
code	O
twice	O
.	O
</s>
