<s>
The	O
DASL	B-Language
Programming	I-Language
Language	I-Language
(	O
Distributed	B-Language
Application	I-Language
Specification	I-Language
Language	I-Language
)	O
is	O
a	O
high-level	O
,	O
strongly	O
typed	O
programming	O
language	O
originally	O
developed	O
at	O
Sun	O
Microsystems	O
Laboratories	O
between	O
1999	O
and	O
2003	O
as	O
part	O
of	O
the	O
.	O
</s>
<s>
The	O
goals	O
of	O
the	O
project	O
were	O
to	O
enable	O
rapid	O
development	O
of	O
web-based	B-Application
applications	I-Application
based	O
on	O
Sun	O
's	O
J2EE	O
architecture	O
,	O
and	O
to	O
eliminate	O
the	O
steep	O
learning	O
curve	O
of	O
platform-specific	O
details	O
.	O
</s>
<s>
DASL	O
defines	O
an	O
application	O
as	O
a	O
domain	B-Application
model	I-Application
with	O
one	O
or	O
more	O
logical	O
presentation	O
models	O
,	O
where	O
a	O
logical	O
presentation	O
model	O
consists	O
of	O
a	O
choreography	O
of	O
the	O
domain	B-Application
model	I-Application
objects	O
described	O
in	O
a	O
set	O
of	O
forms	O
with	O
attached	O
actions	O
.	O
</s>
<s>
DASL	O
generates	O
the	O
graphical	B-Application
user	I-Application
interface	I-Application
directly	O
from	O
the	O
logical	O
presentation	O
.	O
</s>
<s>
DASL	O
is	O
unique	O
among	O
modern	O
application	O
programming	O
languages	O
in	O
its	O
ability	O
to	O
generate	O
a	O
modern	O
graphic	B-Application
user	I-Application
interface	I-Application
for	O
an	O
application	O
without	O
requiring	O
the	O
programmer	O
to	O
define	O
the	O
user	O
interface	O
explicitly	O
,	O
while	O
allowing	O
the	O
programmer	O
to	O
control	O
the	O
look	O
and	O
feel	O
of	O
the	O
generated	O
graphic	B-Application
user	I-Application
interface	I-Application
.	O
</s>
<s>
The	O
language	O
and	O
development	O
environment	O
are	O
a	O
practical	O
realization	O
of	O
the	O
model-driven	B-Architecture
architecture	I-Architecture
(	O
MDA	B-Architecture
)	O
approach	O
.	O
</s>
<s>
Another	O
advantage	O
of	O
using	O
DASL	O
to	O
write	O
applications	O
,	O
rather	O
than	O
conventional	O
3rd	O
generation	O
languages	O
and	O
IDEs	O
is	O
that	O
the	O
DASL	O
code	O
is	O
independent	O
of	O
middleware	O
,	O
GUI	B-Application
presentation	O
frameworks	O
,	O
network	O
topology	O
,	O
and	O
other	O
implementation	O
technologies	O
.	O
</s>
<s>
Today	O
,	O
new	O
DASL	O
generators	O
being	O
written	O
that	O
produce	O
rich	B-Application
web	I-Application
applications	I-Application
.	O
</s>
<s>
Existing	O
DASL	O
applications	O
can	O
thus	O
be	O
converted	O
to	O
rich	B-Application
web	I-Application
applications	I-Application
by	O
recompiling	O
them	O
with	O
the	O
latest	O
code	O
generators	O
.	O
</s>
<s>
A	O
DASL	O
application	O
has	O
two	O
primary	O
components	O
:	O
A	O
business	O
object	O
specification	O
(	O
BOS	O
)	O
that	O
describes	O
the	O
object	O
domain	B-Application
model	I-Application
,	O
consisting	O
of	O
persistent	O
and	O
transient	O
objects	O
representing	O
the	O
domain	O
of	O
the	O
application	O
,	O
and	O
an	O
application	O
usage	O
specification	O
(	O
AUS	O
)	O
that	O
describes	O
the	O
actions	O
or	O
use	O
cases	O
that	O
may	O
be	O
performed	O
on	O
the	O
domain	B-Application
model	I-Application
.	O
</s>
<s>
The	O
DASL	O
programmer	O
models	O
the	O
graphical	B-Application
user	I-Application
interface	I-Application
of	O
the	O
application	O
by	O
annotating	O
the	O
logical	O
AUS	O
forms	O
and	O
actions	O
with	O
properties	O
that	O
describe	O
the	O
basic	O
layout	O
of	O
the	O
data	O
on	O
the	O
page	O
.	O
</s>
<s>
Rather	O
than	O
user	O
interface	O
considerations	O
dominating	O
the	O
application	O
specification	O
,	O
in	O
DASL	O
the	O
logical	O
interaction	O
between	O
the	O
user	O
and	O
domain	B-Application
model	I-Application
is	O
central	O
,	O
and	O
the	O
user	O
interface	O
is	O
derived	O
from	O
the	O
logical	O
interaction	O
.	O
</s>
<s>
Around	O
1999	O
,	O
two	O
Sun	O
researchers	O
,	O
Bruce	O
Daniels	O
and	O
Bob	O
Goldberg	O
,	O
started	O
a	O
research	O
project	O
in	O
Sun	O
Labs	O
called	O
the	O
,	O
with	O
the	O
goal	O
of	O
simplifying	O
the	O
creation	O
of	O
Java	O
web-based	B-Application
enterprise	O
applications	O
.	O
</s>
<s>
The	O
RD3	O
language	O
enhancements	O
and	O
code	O
generators	O
for	O
DASL	O
have	O
made	O
the	O
language	O
extensible	B-Architecture
and	O
have	O
broadened	O
the	O
scope	O
of	O
the	O
language	O
from	O
dynamic	O
HTTP-style	O
web	B-Application
applications	I-Application
to	O
rich	B-Application
web	I-Application
applications	I-Application
.	O
</s>
<s>
The	O
language	O
has	O
been	O
extended	O
so	O
it	O
can	O
define	O
dynamic	O
websites	O
and	O
domain-specific	O
web	O
portals	O
that	O
include	O
cloud	B-Architecture
applications	I-Architecture
.	O
</s>
<s>
The	O
DASL	O
language	O
has	O
been	O
made	O
extensible	B-Architecture
.	O
</s>
<s>
A	O
third	O
party	O
programmer	O
can	O
write	O
a	O
code	O
generator	O
plugin	B-Application
in	O
Java	O
targeted	O
to	O
a	O
specific	O
DASL	O
object	O
class	O
or	O
form	O
,	O
allowing	O
that	O
object	O
or	O
form	O
to	O
be	O
presented	O
using	O
a	O
custom	O
widget	O
.	O
</s>
<s>
DASL	O
is	O
unique	O
among	O
modern	O
application	O
programming	O
languages	O
in	O
its	O
ability	O
to	O
generate	O
a	O
modern	O
graphic	B-Application
user	I-Application
interface	I-Application
for	O
an	O
application	O
without	O
requiring	O
the	O
programmer	O
to	O
define	O
the	O
user	O
interface	O
explicitly	O
.	O
</s>
<s>
Using	O
code	O
generator	O
plugins	B-Application
,	O
the	O
programmer	O
can	O
extend	O
DASL	O
to	O
generate	O
a	O
specific	O
desired	O
user	O
interface	O
.	O
</s>
