<s>
Concerto	O
is	O
a	O
web-based	O
digital	O
signage	O
application	O
licensed	O
under	O
the	O
Apache	B-Application
License	I-Application
and	O
written	O
using	O
the	O
Ruby	B-Application
on	I-Application
Rails	I-Application
programming	O
framework	O
.	O
</s>
<s>
Originally	O
developed	O
by	O
students	O
at	O
Rensselaer	O
Polytechnic	O
Institute	O
in	O
2008	O
,	O
Concerto	O
was	O
originally	O
written	O
in	O
the	O
PHP	B-Application
programming	I-Application
language	I-Application
and	O
used	O
widely	O
at	O
Rensselaer	O
Polytechnic	O
Institute	O
and	O
other	O
universities	O
.	O
</s>
<s>
The	O
software	O
was	O
rewritten	O
in	O
2012	O
using	O
the	O
Ruby	B-Application
on	I-Application
Rails	I-Application
programming	O
framework	O
.	O
</s>
<s>
Packages	O
for	O
Linux	B-Application
distributions	O
(	O
such	O
as	O
Debian	O
)	O
and	O
virtual	O
machine	O
images	O
were	O
released	O
to	O
lessen	O
user	O
difficult	O
in	O
deploying	O
Ruby	B-Application
on	I-Application
Rails	I-Application
applications	O
,	O
compared	O
with	O
the	O
version	O
1	O
PHP	B-Application
application	O
.	O
</s>
<s>
Templates	B-Application
Each	O
screen	O
in	O
Concerto	O
has	O
a	O
graphical	O
template	O
associated	O
with	O
it	O
,	O
that	O
dictates	O
the	O
look	O
and	O
feel	O
of	O
the	O
screen	O
as	O
well	O
as	O
the	O
layout	O
of	O
the	O
content	O
displayed	O
on	O
it	O
.	O
</s>
<s>
Internationalization	O
Concerto	O
supports	O
UTF-8	O
languages	O
through	O
the	O
translation	O
of	O
YAML	B-Protocol
files	O
.	O
</s>
<s>
Its	O
frontend	O
,	O
which	O
displays	O
the	O
content	O
inside	O
of	O
templates	B-Application
,	O
can	O
run	O
in	O
any	O
web	O
browser	O
that	O
has	O
Web	B-Language
Components	I-Language
support	O
under	O
the	O
Polymer	O
JavaScript	B-Language
framework	O
.	O
</s>
<s>
Owing	O
to	O
its	O
use	O
in	O
low-cost	O
deployment	O
situations	O
,	O
considerable	O
discussion	O
has	O
taken	O
place	O
regarding	O
the	O
use	O
of	O
the	O
Raspberry	B-Operating_System
Pi	I-Operating_System
Single-board	B-Device
computer	I-Device
running	O
a	O
web	O
browser	O
for	O
displaying	O
Concerto	O
content	O
.	O
</s>
<s>
Despite	O
some	O
performance	O
issues	O
,	O
Concerto	O
and	O
a	O
number	O
of	O
other	O
digital	O
signage	O
systems	O
can	O
be	O
used	O
with	O
some	O
minor	O
modifications	O
on	O
the	O
Raspberry	B-Operating_System
Pi	I-Operating_System
.	O
</s>
