<s>
Shiny	B-Application
is	O
a	O
free	B-License
and	I-License
open	I-License
source	I-License
R	B-Language
package	I-Language
for	O
developing	O
web	B-Application
applications	I-Application
(	O
apps	O
)	O
.	O
</s>
<s>
It	O
was	O
announced	O
by	O
Joe	O
Cheng	O
,	O
CTO	O
of	O
RStudio	B-Application
,	O
in	O
2012	O
.	O
</s>
<s>
One	O
of	O
the	O
uses	O
of	O
Shiny	B-Application
has	O
been	O
in	O
fast	O
prototyping	O
.	O
</s>
<s>
A	O
separate	O
implementation	O
Shiny	B-Application
for	O
Python	O
,	O
is	O
already	O
available	O
as	O
alpha	O
software	O
,	O
and	O
while	O
the	O
goal	O
is	O
the	O
same	O
,	O
it	O
uses	O
Python	O
syntax	O
(	O
and	O
semantics	O
)	O
so	O
it	O
's	O
not	O
fully	O
compatible	O
.	O
</s>
<s>
There	O
is	O
also	O
Shinylive	O
,	O
for	O
the	O
Python	O
version	O
(	O
only	O
,	O
at	O
least	O
for	O
now	O
)	O
,	O
that	O
allows	O
running	O
shiny	B-Application
on	O
the	O
client	O
(	O
i.e.	O
</s>
<s>
Shiny	B-Application
creates	O
a	O
reactive	B-Architecture
context	O
wherein	O
the	O
user	O
specifies	O
,	O
through	O
input	O
variables	O
,	O
the	O
circumstances	O
under	O
which	O
computations	O
are	O
re-executed	O
,	O
or	O
graphs	O
(	O
often	O
visualizations	O
)	O
re-rendered	O
;	O
this	O
occurs	O
almost	O
instantaneously	O
.	O
</s>
<s>
The	O
input	O
variables	O
are	O
evaluated	O
via	O
a	O
user	B-Application
interface	I-Application
which	O
allows	O
the	O
simple	O
creation	O
of	O
widgets	O
such	O
as	O
text	O
boxes	O
,	O
radio	O
buttons	O
,	O
and	O
drop-down	O
lists	O
.	O
</s>
<s>
There	O
are	O
two	O
main	O
parts	O
to	O
a	O
Shiny	B-Application
file	O
,	O
which	O
may	O
alternatively	O
be	O
stored	O
in	O
two	O
separate	O
files	O
.	O
</s>
<s>
One	O
is	O
designed	O
to	O
accommodate	O
the	O
user	B-Application
interface	I-Application
,	O
the	O
appearance	O
of	O
which	O
is	O
restricted	O
by	O
the	O
default	O
choices	O
,	O
though	O
can	O
be	O
extended	O
through	O
various	O
other	O
R	B-Language
packages	I-Language
.	O
</s>
<s>
The	O
other	O
is	O
designed	O
to	O
accommodate	O
the	O
server	O
computations	O
and	O
plot	O
generating	O
code	O
,	O
for	O
which	O
all	O
the	O
built-in	O
facilities	O
of	O
R	B-Language
are	O
available	O
.	O
</s>
<s>
Hosting	O
a	O
Shiny	B-Application
app	O
on	O
an	O
RStudio	B-Application
server	O
is	O
free	O
up	O
to	O
certain	O
limits	O
.	O
</s>
