<s>
Urbi	B-Application
is	O
an	O
open-source	B-Application
cross-platform	B-Operating_System
software	I-Operating_System
computing	B-Device
platform	I-Device
written	O
in	O
C++	B-Language
used	O
to	O
develop	O
applications	O
for	O
robotics	O
and	O
complex	O
systems	O
.	O
</s>
<s>
Urbi	B-Application
is	O
based	O
on	O
the	O
UObject	O
distributed	O
C++	B-Language
component	O
architecture	O
.	O
</s>
<s>
It	O
also	O
includes	O
the	O
urbiscript	B-Language
orchestration	B-Application
language	O
which	O
is	O
a	O
parallel	O
and	O
event-driven	O
script	O
language	O
.	O
</s>
<s>
UObject	O
components	O
can	O
be	O
plugged	O
into	O
urbiscript	B-Language
and	O
appear	O
as	O
native	O
objects	O
that	O
can	O
be	O
scripted	O
to	O
specify	O
their	O
interactions	O
and	O
data	O
exchanges	O
.	O
</s>
<s>
UObjects	O
can	O
be	O
linked	O
to	O
the	O
urbiscript	B-Language
interpreter	O
,	O
or	O
executed	O
as	O
autonomous	O
processes	O
in	O
"	O
remote	O
"	O
mode	O
.	O
</s>
<s>
The	O
urbiscript	B-Language
language	O
was	O
created	O
in	O
2003	O
by	O
Jean-Christophe	O
Baillie	O
in	O
the	O
Cognitive	O
Robotics	O
Lab	O
of	O
ENSTA	O
,	O
Paris	O
.	O
</s>
<s>
It	O
is	O
now	O
an	O
open	O
source	O
project	O
,	O
with	O
a	O
BSD	B-Operating_System
license	I-Operating_System
,	O
available	O
on	O
GitHub	B-Application
.	O
</s>
<s>
The	O
urbiscript	B-Language
language	O
can	O
be	O
best	O
described	O
as	O
an	O
orchestration	B-Application
script	O
language	O
:	O
like	O
Lua	B-Language
in	O
video	O
games	O
,	O
urbiscript	B-Language
can	O
be	O
used	O
to	O
glue	O
together	O
C++	B-Language
components	O
into	O
a	O
functional	O
behavior	O
,	O
the	O
CPU-intensive	O
algorithmic	O
part	O
being	O
left	O
to	O
C++	B-Language
and	O
the	O
behavior	O
scripting	O
part	O
being	O
left	O
to	O
the	O
script	O
language	O
which	O
is	O
more	O
flexible	O
,	O
easy	O
to	O
maintain	O
and	O
allows	O
dynamic	O
interaction	O
during	O
program	O
execution	O
.	O
</s>
<s>
As	O
an	O
orchestration	B-Application
language	O
,	O
urbiscript	B-Language
also	O
brings	O
some	O
useful	O
abstractions	O
to	O
a	O
program	O
by	O
having	O
parallelism	B-Operating_System
and	O
event-based	B-Application
programming	I-Application
as	O
part	O
of	O
the	O
language	O
semantics	O
.	O
</s>
<s>
The	O
scripting	O
of	O
parallel	O
behaviors	O
and	O
reactions	O
to	O
events	O
are	O
core	O
requirements	O
of	O
most	O
robotic	O
and	O
complex	O
AI	O
applications	O
,	O
therefore	O
urbiscript	B-Language
(	O
and	O
the	O
whole	O
Urbi	B-Application
platform	O
)	O
is	O
well	O
suited	O
to	O
such	O
applications	O
.	O
</s>
<s>
Cross	B-Operating_System
platform	I-Operating_System
:	O
Linux	B-Application
,	O
Macintosh	O
,	O
Windows	O
,	O
others	O
.	O
</s>
<s>
Embeddable	O
,	O
Urbi	B-Application
can	O
run	O
on	O
various	O
processors	O
:	O
x86	B-Operating_System
,	O
ARM	B-Architecture
,	O
MIPS	B-Device
,	O
powerPC	B-Architecture
,	O
etc	O
.	O
</s>
<s>
The	O
example	O
below	O
shows	O
how	O
to	O
write	O
a	O
ball	O
tracking	O
action/perception	O
loop	O
in	O
urbiscript	B-Language
:	O
are	O
two	O
motor	O
objects	O
,	O
and	O
ball	O
is	O
the	O
ball	O
detection	O
object	O
(	O
x	O
and	O
y	O
range	O
from	O
-1/2	O
to	O
1/2	O
)	O
:	O
</s>
<s>
The	O
UObject	O
component	O
architecture	O
allows	O
developers	O
to	O
interface	O
any	O
Java/C	O
++	O
object	O
within	O
Urbi	B-Application
,	O
making	O
selected	O
methods	O
and	O
attributes	O
visible	O
in	O
urbiscript	B-Language
,	O
while	O
in	O
fact	O
being	O
compiled	O
code	O
.	O
</s>
<s>
Special	O
notifiers	O
can	O
be	O
set	O
on	O
any	O
of	O
the	O
object	O
's	O
attributes	O
to	O
notify	O
the	O
C++	B-Language
side	O
of	O
any	O
change	O
on	O
these	O
attributes	O
on	O
the	O
urbiscript/Urbi	O
side	O
.	O
</s>
<s>
UObject	O
uses	O
C++	B-Language
templates	O
to	O
transparently	O
map	O
any	O
requested	O
method	O
to	O
an	O
interface	O
machinery	O
that	O
takes	O
care	O
of	O
the	O
type	O
checking	O
.	O
</s>
<s>
A	O
UObject	O
can	O
be	O
used	O
in	O
plugged	O
mode	O
if	O
it	O
is	O
directly	O
linked	O
to	O
Urbi	B-Application
at	O
compile	O
time	O
or	O
with	O
dynamic	O
loading	O
.	O
</s>
<s>
In	O
that	O
case	O
,	O
the	O
C++	B-Language
object	O
shares	O
the	O
Urbi	B-Application
memory	O
directly	O
,	O
resulting	O
in	O
efficient	O
integration	O
.	O
</s>
<s>
In	O
that	O
case	O
,	O
it	O
will	O
become	O
an	O
autonomous	O
program	O
to	O
be	O
executed	O
with	O
the	O
IP	O
address	O
of	O
the	O
Urbi	B-Application
server	O
as	O
a	O
parameter	O
.	O
</s>
<s>
In	O
both	O
cases	O
,	O
the	O
object	O
will	O
transparently	O
appear	O
in	O
urbiscript	B-Language
as	O
a	O
native	O
urbiscript	B-Language
object	O
.	O
</s>
<s>
Webots	B-Application
is	O
the	O
official	O
robot	O
simulator	O
compatible	O
with	O
Urbi	B-Application
.	O
</s>
<s>
Player/Stage	B-Application
integration	O
has	O
been	O
reported	O
,	O
although	O
it	O
is	O
not	O
currently	O
released	O
.	O
</s>
