<s>
CaRMetal	B-Language
is	O
an	O
interactive	B-Application
geometry	I-Application
program	O
which	O
inherited	O
the	O
C.a.R.	B-Language
</s>
<s>
The	O
software	O
has	O
been	O
created	O
by	O
Eric	O
Hakenholz	O
,	O
in	O
Java	B-Language
.	O
</s>
<s>
CaRMetal	B-Language
is	O
free	O
,	O
under	O
GNU	B-License
GPL	I-License
license	I-License
.	O
</s>
<s>
It	O
keeps	O
an	O
amount	O
of	O
functionality	O
of	O
C.a.R.	B-Language
</s>
<s>
CaRMetal	B-Language
also	O
supports	O
a	O
configurable	O
restricted	O
construction	O
palette	O
and	O
has	O
assignment	O
capabilities	O
,	O
which	O
use	O
an	O
apparently	O
unique	O
feature	O
called	O
Monkey	O
.	O
</s>
<s>
CaRMetal	B-Language
has	O
a	O
scripting	O
language	O
(	O
JavaScript	B-Language
)	O
which	O
allows	O
the	O
user	O
to	O
build	O
rather	O
complex	O
figures	O
like	O
fractals	B-Application
.	O
</s>
<s>
CaRMetal	B-Language
has	O
several	O
locales	O
including	O
French	O
,	O
English	O
,	O
Spanish	O
,	O
German	O
,	O
Italian	O
,	O
Dutch	O
,	O
Portuguese	O
and	O
Arabic	O
.	O
</s>
<s>
This	O
constant	O
interaction	O
between	O
the	O
pupil	O
and	O
the	O
object	O
of	O
experimentation	O
is	O
in	O
phase	O
with	O
modern	O
theories	O
about	O
didactics	O
and	O
,	O
in	O
this	O
view	O
,	O
CaRMetal	B-Language
is	O
intended	O
to	O
be	O
used	O
by	O
students	O
.	O
</s>
<s>
The	O
workbooks	O
(	O
see	O
below	O
)	O
can	O
be	O
exported	O
as	O
HTML	B-Language
files	I-Language
,	O
with	O
a	O
restricted	O
tools	O
palette	O
(	O
for	O
example	O
,	O
leaving	O
only	O
the	O
intersection	O
and	O
circle	O
tools	O
lets	O
the	O
pupil	O
make	O
compass-only	O
construction	O
)	O
.	O
</s>
<s>
The	O
macros	O
can	O
be	O
organized	O
in	O
a	O
hierarchy	O
of	O
folders	O
,	O
which	O
make	O
it	O
easy	O
to	O
transform	O
CaRMetal	B-Language
into	O
a	O
tool	O
allowing	O
to	O
explore	O
non-euclidean	O
geometries	O
.	O
</s>
<s>
Since	O
2010	O
,	O
CaRMetal	B-Language
uses	O
a	O
folder	O
system	O
allowing	O
one	O
to	O
put	O
several	O
figures	O
in	O
one	O
folder	O
,	O
called	O
"	O
workbook	O
"	O
.	O
</s>
<s>
CaRMetal	B-Language
allows	O
one	O
to	O
include	O
picture	O
files	O
and	O
JavaScript	B-Language
files	O
into	O
a	O
figure	O
.	O
</s>
<s>
The	O
file	O
extension	O
of	O
a	O
figure	O
is	O
zir	O
like	O
in	O
C.a.R.	B-Language
</s>
<s>
(	O
by	O
the	O
way	O
,	O
there	O
is	O
much	O
compatibility	O
between	O
both	O
software	O
)	O
and	O
the	O
file	O
structure	O
is	O
a	O
meta-description	O
of	O
the	O
figure	O
in	O
the	O
XML	B-Protocol
language	O
.	O
</s>
<s>
Of	O
course	O
when	O
one	O
of	O
the	O
extremities	O
of	O
the	O
segment	O
is	O
moved	O
with	O
the	O
mouse	O
,	O
the	O
text	O
is	O
edited	O
in	O
real	B-General_Concept
time	I-General_Concept
.	O
</s>
<s>
CaRMetal	B-Language
uses	O
HotEqn	O
and	O
JLatexMath	O
which	O
are	O
LaTeX	B-Application
parsers	O
,	O
and	O
it	O
is	O
possible	O
to	O
write	O
LaTeX	B-Application
formulae	O
inside	O
text	O
objects	O
.	O
</s>
<s>
The	O
strength	O
of	O
this	O
feature	O
comes	O
from	O
the	O
fact	O
that	O
it	O
is	O
possible	O
to	O
mix	O
up	O
dynamic	O
texts	O
with	O
LaTeX	B-Application
formulae	O
,	O
getting	O
dynamic	O
LaTeX(when the size of the square changes, the display changes too )	O
!	O
</s>
<s>
CaRMetal	B-Language
allows	O
the	O
user	O
to	O
set	O
some	O
properties	O
of	O
the	O
objects	O
,	O
like	O
their	O
color	O
or	O
the	O
fact	O
that	O
they	O
are	O
visible	O
or	O
not	O
,	O
as	O
conditional	B-Language
.	O
</s>
<s>
An	O
important	O
application	O
of	O
these	O
features	O
was	O
the	O
2.5D	O
mode	O
of	O
CaRMetal	B-Language
,	O
emulating	O
3D	O
geometry	O
.	O
</s>
<s>
Since	O
the	O
version	O
4.0	O
CaRMetal	B-Language
has	O
a	O
real	O
3D	O
mode	O
which	O
comes	O
up	O
with	O
a	O
regular	O
tetrahedron	O
,	O
a	O
cube	B-Application
,	O
a	O
diamond	O
and	O
a	O
regular	O
dodecahedron	O
.	O
</s>
<s>
This	O
feature	O
,	O
inherited	O
from	O
C.a.R.	B-Language
,	O
is	O
based	O
on	O
barycentric	O
coordinates	O
.	O
</s>
<s>
Since	O
the	O
4.1	O
version	O
CaRMetal	B-Language
permits	O
some	O
turtle	O
graphics	O
(	O
programmed	O
in	O
JavaScript	B-Language
)	O
either	O
in	O
2D	O
or	O
in	O
3D	O
.	O
</s>
<s>
A	O
point	O
can	O
be	O
made	O
magnetic	O
with	O
a	O
distance	O
and	O
a	O
list	O
of	O
objects	O
it	O
is	O
attracted	O
to	O
whenever	O
the	O
point	O
is	O
sufficiently	O
near	O
one	O
or	O
several	O
of	O
these	O
objects	O
(	O
sufficiently	O
near	O
means	O
that	O
the	O
distance	O
between	O
them	O
is	O
less	O
than	O
the	O
minimal	O
distance	O
which	O
is	O
a	O
property	O
of	O
the	O
point	O
,	O
and	O
is	O
measured	O
in	O
pixel	B-Algorithm
units	O
)	O
.	O
</s>
<s>
Since	O
2013	O
there	O
is	O
the	O
possibility	O
to	O
run	O
one	O
CaRMetal	B-Language
figure	O
as	O
server	O
(	O
typically	O
,	O
the	O
teacher	O
's	O
one	O
)	O
and	O
several	O
as	O
clients	O
.	O
</s>
<s>
Such	O
scripting	O
tools	O
exist	O
also	O
in	O
DrGeo	B-Application
,	O
Kig	B-Language
and	O
Cinderella	B-Application
(	O
software	O
)	O
.	O
</s>
<s>
This	O
allows	O
some	O
kind	O
of	O
inverse	B-General_Concept
kinematics	I-General_Concept
much	O
like	O
with	O
GeoLicia	O
.	O
</s>
<s>
To	O
create	O
a	O
geometric	O
object	O
in	O
JavaScript	B-Language
it	O
suffices	O
to	O
click	O
on	O
an	O
icon	O
representing	O
the	O
object	O
.	O
</s>
<s>
The	O
JavaScript	B-Language
instruction	O
appears	O
in	O
the	O
editor	O
,	O
with	O
predefined	O
parameters	O
.	O
</s>
<s>
This	O
is	O
a	O
common	O
feature	O
with	O
Kig	B-Language
(	O
but	O
in	O
this	O
case	O
,	O
the	O
language	O
is	O
Python	B-Language
(	O
language	O
)	O
)	O
and	O
DrGeo	B-Application
(	O
in	O
this	O
case	O
,	O
with	O
Scheme	O
(	O
language	O
)	O
)	O
.	O
</s>
<s>
It	O
is	O
also	O
possible	O
to	O
set	O
the	O
coordinates	O
of	O
a	O
point	O
as	O
character	O
strings	O
written	O
in	O
the	O
language	O
of	O
CaRMetal	B-Language
.	O
</s>
<s>
As	O
an	O
example	O
,	O
the	O
Sierpinski	O
triangle	O
can	O
be	O
built	O
up	O
as	O
an	O
iterated	B-Algorithm
function	I-Algorithm
system	I-Algorithm
with	O
this	O
recursive	O
script	O
,	O
which	O
is	O
rather	O
short	O
because	O
of	O
the	O
already	O
available	O
graphic	O
instructions	O
such	O
as	O
MidPoint	O
:	O
</s>
<s>
String	O
and	O
RegExp	B-Language
objects	O
,	O
which	O
make	O
it	O
easy	O
to	O
implement	O
L-systems	B-Language
;	O
</s>
<s>
General	O
JavaScript	B-Language
objects	O
can	O
be	O
used	O
to	O
create	O
new	O
geometric	O
objects	O
like	O
complex	O
numbers	O
,	O
matrices	B-Architecture
etc	O
.	O
</s>
<s>
This	O
object-oriented	B-Language
programming	I-Language
works	O
much	O
like	O
Kig	B-Language
's	O
Python	B-Language
scripts	I-Language
,	O
but	O
as	O
of	O
today	O
no	O
one	O
seems	O
to	O
have	O
publish	O
anything	O
using	O
that	O
.	O
</s>
