<s>
A	O
UML	B-Application
tool	I-Application
is	O
a	O
software	B-Application
application	I-Application
that	O
supports	O
some	O
or	O
all	O
of	O
the	O
notation	O
and	O
semantics	O
associated	O
with	O
the	O
Unified	B-Language
Modeling	I-Language
Language	I-Language
(	O
UML	B-Language
)	O
,	O
which	O
is	O
the	O
industry	O
standard	O
general-purpose	B-General_Concept
modeling	I-General_Concept
language	I-General_Concept
for	O
software	B-General_Concept
engineering	I-General_Concept
.	O
</s>
<s>
UML	B-Application
tool	I-Application
is	O
used	O
broadly	O
here	O
to	O
include	O
application	B-Application
programs	I-Application
which	O
are	O
not	O
exclusively	O
focused	O
on	O
UML	B-Language
,	O
but	O
which	O
support	O
some	O
functions	O
of	O
the	O
Unified	B-Language
Modeling	I-Language
Language	I-Language
,	O
either	O
as	O
an	O
add-on	O
,	O
as	O
a	O
component	O
or	O
as	O
a	O
part	O
of	O
their	O
overall	O
functionality	O
.	O
</s>
<s>
UML	B-Protocol
tools	I-Protocol
support	O
the	O
following	O
kinds	O
of	O
functionality	O
:	O
</s>
<s>
Diagramming	O
in	O
this	O
context	O
means	O
creating	O
and	O
editing	O
UML	B-Language
diagrams	I-Language
;	O
that	O
is	O
diagrams	O
that	O
follow	O
the	O
graphical	O
notation	O
of	O
the	O
Unified	B-Language
Modeling	I-Language
Language	I-Language
.	O
</s>
<s>
The	O
use	O
of	O
UML	B-Language
diagrams	I-Language
as	O
a	O
means	O
to	O
draw	O
diagrams	O
of	O
–	O
mostly	O
–	O
object-oriented	B-Language
software	O
is	O
generally	O
agreed	O
upon	O
by	O
software	O
developers	O
.	O
</s>
<s>
When	O
developers	O
draw	O
diagrams	O
of	O
object-oriented	B-Language
software	O
,	O
they	O
usually	O
follow	O
the	O
UML	B-Language
notation	O
.	O
</s>
<s>
Round-trip	B-Application
engineering	I-Application
refers	O
to	O
the	O
ability	O
of	O
a	O
UML	B-Application
tool	I-Application
to	O
perform	O
code	B-Application
generation	I-Application
from	O
models	O
,	O
and	O
model	O
generation	O
from	O
code	O
(	O
a.k.a.	O
,	O
reverse	O
engineering	O
)	O
,	O
while	O
keeping	O
both	O
the	O
model	O
and	O
the	O
code	O
semantically	O
consistent	O
with	O
each	O
other	O
.	O
</s>
<s>
Code	B-Application
generation	I-Application
and	O
reverse	O
engineering	O
are	O
explained	O
in	O
more	O
detail	O
below	O
.	O
</s>
<s>
Code	B-Application
generation	I-Application
in	O
this	O
context	O
means	O
that	O
the	O
user	O
creates	O
UML	B-Language
diagrams	I-Language
,	O
which	O
have	O
some	O
connected	O
model	O
data	O
,	O
and	O
the	O
UML	B-Application
tool	I-Application
derives	O
from	O
the	O
diagrams	O
part	O
or	O
all	O
of	O
the	O
source	O
code	O
for	O
the	O
software	O
system	O
.	O
</s>
<s>
In	O
some	O
tools	O
the	O
user	O
can	O
provide	O
a	O
skeleton	O
of	O
the	O
program	O
source	O
code	O
,	O
in	O
the	O
form	O
of	O
a	O
source	O
code	O
template	B-Application
,	O
where	O
predefined	O
tokens	O
are	O
then	O
replaced	O
with	O
program	O
source	O
code	O
parts	O
during	O
the	O
code	B-Application
generation	I-Application
process	O
.	O
</s>
<s>
An	O
often	O
cited	O
criticism	O
is	O
that	O
the	O
UML	B-Language
diagrams	I-Language
lack	O
the	O
detail	O
that	O
is	O
needed	O
to	O
contain	O
the	O
same	O
information	O
as	O
is	O
covered	O
with	O
the	O
program	O
source	O
:	O
Jack	O
W	O
.	O
Reeves	O
states	O
that	O
the	O
final	O
embodiment	O
of	O
the	O
design	O
lies	O
in	O
the	O
source	O
code	O
.	O
</s>
<s>
(	O
His	O
often	O
quoted	O
statement	O
that	O
"	O
the	O
Code	O
is	O
the	O
design	O
"	O
has	O
been	O
misinterpreted	O
to	O
mean	O
that	O
there	O
is	O
no	O
need	O
for	O
intermediate	O
-	O
and	O
high-level	O
software-design	O
artifacts	O
,	O
such	O
as	O
UML	B-Language
diagrams	I-Language
or	O
software-requirements	O
documents	O
)	O
.	O
</s>
<s>
Reverse	O
engineering	O
in	O
this	O
context	O
means	O
,	O
that	O
the	O
UML	B-Application
tool	I-Application
reads	O
program	O
source	O
code	O
as	O
input	O
and	O
derives	O
model	O
data	O
and	O
corresponding	O
graphical	O
UML	B-Language
diagrams	I-Language
from	O
it	O
(	O
as	O
opposed	O
to	O
the	O
somewhat	O
broader	O
meaning	O
described	O
in	O
the	O
article	O
"	O
Reverse	O
engineering	O
"	O
)	O
.	O
</s>
<s>
Diagram	O
data	O
is	O
normally	O
not	O
contained	O
with	O
the	O
program	O
source	O
,	O
such	O
that	O
the	O
UML	B-Application
tool	I-Application
,	O
at	O
least	O
in	O
the	O
initial	O
step	O
,	O
has	O
to	O
create	O
some	O
random	O
layout	O
of	O
the	O
graphical	O
symbols	O
of	O
the	O
UML	B-Language
notation	O
or	O
use	O
some	O
automatic	O
layout	B-Algorithm
algorithm	I-Algorithm
to	O
place	O
the	O
symbols	O
in	O
a	O
way	O
that	O
the	O
user	O
can	O
understand	O
the	O
diagram	O
.	O
</s>
<s>
Usually	O
,	O
the	O
user	O
of	O
such	O
a	O
functionality	O
of	O
a	O
UML	B-Application
tool	I-Application
has	O
to	O
manually	O
edit	O
those	O
automatically	O
generated	O
diagrams	O
to	O
attain	O
some	O
meaningfulness	O
.	O
</s>
<s>
It	O
also	O
often	O
does	O
n't	O
make	O
sense	O
to	O
draw	O
diagrams	O
of	O
the	O
whole	O
program	O
source	O
,	O
as	O
that	O
represents	O
just	O
too	O
much	O
detail	O
to	O
be	O
of	O
interest	O
at	O
the	O
level	O
of	O
the	O
UML	B-Language
diagrams	I-Language
.	O
</s>
<s>
There	O
are	O
language	O
features	O
of	O
some	O
programming	O
languages	O
,	O
like	O
class	O
-	O
or	O
function	O
templates	B-Application
of	O
the	O
C++	B-Language
programming	I-Language
language	I-Language
,	O
which	O
are	O
notoriously	O
hard	O
to	O
convert	O
automatically	O
to	O
UML	B-Language
diagrams	I-Language
in	O
their	O
full	O
complexity	O
.	O
</s>
<s>
XML	B-Language
Metadata	I-Language
Interchange	I-Language
(	O
XMI	O
)	O
is	O
the	O
format	O
for	O
UML	B-Language
model	O
interchange	O
.	O
</s>
<s>
XMI	O
does	O
not	O
support	O
UML	B-Language
Diagram	I-Language
Interchange	O
,	O
which	O
allows	O
the	O
importation	O
of	O
UML	B-Language
diagrams	I-Language
from	O
one	O
model	O
to	O
another	O
.	O
</s>
<s>
A	O
key	O
concept	O
associated	O
with	O
the	O
model-driven	B-Architecture
architecture	I-Architecture
initiative	O
is	O
the	O
capacity	O
to	O
transform	O
a	O
model	O
into	O
another	O
model	O
.	O
</s>
<s>
It	O
is	O
also	O
possible	O
to	O
refactor	O
UML	B-Language
models	O
to	O
produce	O
more	O
concise	O
and	O
well-formed	O
UML	B-Language
models	O
.	O
</s>
<s>
It	O
is	O
possible	O
to	O
generate	O
UML	B-Language
models	O
from	O
other	O
modeling	O
notations	O
,	O
such	O
as	O
BPMN	B-Architecture
,	O
which	O
is	O
itself	O
a	O
UML	B-Language
profile	I-Language
.	O
</s>
<s>
The	O
standard	O
that	O
supports	O
this	O
is	O
called	O
QVT	B-Language
for	O
Queries/Views/Transformations	O
.	O
</s>
<s>
One	O
example	O
of	O
an	O
open-source	O
QVT-solution	O
is	O
the	O
ATL	B-Language
language	O
built	O
by	O
INRIA	O
.	O
</s>
