<s>
Less	O
(	O
Leaner	O
Style	O
Sheets	O
;	O
sometimes	O
stylized	O
as	O
LESS	O
)	O
is	O
a	O
dynamic	O
preprocessor	B-General_Concept
style	B-Language
sheet	I-Language
language	I-Language
that	O
can	O
be	O
compiled	O
into	O
Cascading	B-Language
Style	I-Language
Sheets	I-Language
(	O
CSS	B-Language
)	O
and	O
run	O
on	O
the	O
client	O
side	O
or	O
server	O
side	O
.	O
</s>
<s>
Designed	O
by	O
Alexis	O
Sellier	O
,	O
Less	O
is	O
influenced	O
by	O
Sass	B-Language
and	O
has	O
influenced	O
the	O
newer	O
"	O
SCSS	B-Language
"	O
syntax	O
of	O
Sass	B-Language
,	O
which	O
adapted	O
its	O
CSS-like	O
block	O
formatting	O
syntax	O
.	O
</s>
<s>
Less	O
is	O
an	O
open	B-Application
source	I-Application
project	O
.	O
</s>
<s>
Its	O
first	O
version	O
was	O
written	O
in	O
Ruby	B-Language
;	O
however	O
,	O
in	O
the	O
later	O
versions	O
,	O
use	O
of	O
Ruby	B-Language
has	O
been	O
deprecated	B-General_Concept
and	O
replaced	O
by	O
JavaScript	B-Language
.	O
</s>
<s>
The	O
indented	O
syntax	O
of	O
Less	O
is	O
a	O
nested	O
metalanguage	O
,	O
as	O
valid	O
CSS	B-Language
is	O
valid	O
Less	O
code	O
with	O
the	O
same	O
semantics	B-Application
.	O
</s>
<s>
Less	O
provides	O
the	O
following	O
mechanisms	O
:	O
variables	O
,	O
nesting	O
,	O
mixins	B-Language
,	O
operators	O
and	O
functions	O
;	O
the	O
main	O
difference	O
between	O
Less	O
and	O
other	O
CSS	B-Language
precompilers	O
is	O
that	O
Less	O
allows	O
real-time	O
compilation	O
via	O
less.js	B-Language
by	O
the	O
browser	O
.	O
</s>
<s>
During	O
translation	O
,	O
the	O
values	O
of	O
the	O
variables	O
are	O
inserted	O
into	O
the	O
output	O
CSS	B-Language
document	O
.	O
</s>
<s>
The	O
code	O
above	O
in	O
Less	O
would	O
compile	O
to	O
the	O
following	O
CSS	B-Language
code	O
.	O
</s>
<s>
Mixins	B-Language
allows	O
embedding	O
all	O
the	O
properties	O
of	O
a	O
class	O
into	O
another	O
class	O
by	O
including	O
the	O
class	O
name	O
as	O
one	O
of	O
its	O
property	O
,	O
thus	O
behaving	O
as	O
a	O
sort	O
of	O
constant	O
or	O
variable	O
.	O
</s>
<s>
CSS	B-Language
does	O
not	O
support	O
Mixins	B-Language
:	O
Any	O
repeated	O
code	O
must	O
be	O
repeated	O
in	O
each	O
location	O
.	O
</s>
<s>
Mixins	B-Language
allows	O
for	O
more	O
efficient	O
and	O
clean	O
code	O
repetitions	O
,	O
as	O
well	O
as	O
easier	O
alteration	O
of	O
code	O
.	O
</s>
<s>
The	O
above	O
code	O
in	O
Less	O
would	O
compile	O
to	O
the	O
following	O
CSS	B-Language
code	O
:	O
</s>
<s>
Less	O
has	O
a	O
special	O
type	O
of	O
ruleset	O
called	O
parametric	O
mixins	B-Language
which	O
can	O
be	O
mixed	O
in	O
like	O
classes	O
,	O
but	O
accepts	O
parameters	O
.	O
</s>
<s>
The	O
above	O
code	O
in	O
Less	O
would	O
compile	O
to	O
the	O
following	O
CSS	B-Language
code	O
:	O
</s>
<s>
Functions	O
map	O
one-to-one	O
with	O
JavaScript	B-Language
code	O
,	O
allowing	O
manipulation	O
of	O
values	O
.	O
</s>
<s>
The	O
above	O
code	O
in	O
Less	O
would	O
compile	O
to	O
the	O
following	O
CSS	B-Language
code	O
:	O
</s>
<s>
Both	O
Sass	B-Language
and	O
Less	O
are	O
CSS	B-Language
preprocessors	B-General_Concept
,	O
which	O
allow	O
writing	O
clean	O
CSS	B-Language
in	O
a	O
programming	O
construct	O
instead	O
of	O
static	O
rules	O
.	O
</s>
<s>
Less	O
is	O
inspired	O
by	O
Sass	B-Language
.	O
</s>
<s>
Sass	B-Language
was	O
designed	O
to	O
both	O
simplify	O
and	O
extend	O
CSS	B-Language
,	O
so	O
things	O
like	O
curly	O
braces	O
were	O
removed	O
from	O
the	O
syntax	O
.	O
</s>
<s>
Less	O
was	O
designed	O
to	O
be	O
as	O
close	O
to	O
CSS	B-Language
as	O
possible	O
,	O
and	O
as	O
a	O
result	O
existing	O
CSS	B-Language
can	O
be	O
used	O
as	O
valid	O
Less	O
code	O
.	O
</s>
<s>
The	O
newer	O
versions	O
of	O
Sass	B-Language
also	O
introduced	O
a	O
CSS-like	O
syntax	O
called	O
SCSS	B-Language
(	O
Sassy	O
CSS	B-Language
)	O
.	O
</s>
<s>
One	O
option	O
is	O
to	O
include	O
the	O
less.js	B-Language
JavaScript	B-Language
file	O
to	O
convert	O
the	O
code	O
on-the-fly	O
.	O
</s>
<s>
The	O
browser	O
then	O
renders	O
the	O
output	O
CSS	B-Language
.	O
</s>
<s>
Another	O
option	O
is	O
to	O
render	O
the	O
Less	O
code	O
into	O
pure	O
CSS	B-Language
and	O
upload	O
the	O
CSS	B-Language
to	O
a	O
site	O
.	O
</s>
<s>
With	O
this	O
option	O
no	O
.less	B-Language
files	O
are	O
uploaded	O
and	O
the	O
site	O
does	O
not	O
need	O
the	O
less.js	B-Language
JavaScript	B-Language
converter	O
.	O
</s>
<s>
Name	O
Description	O
Software	O
License	O
Platform	O
Functionality	O
WinLess	O
-	O
Windows	O
GUI	O
for	O
less.js	B-Language
GUI	O
Less	O
Compiler	O
Apache	B-Application
2.0	I-Application
Windows	O
Compiler	O
Crunch	O
Less	O
editor	O
and	O
compiler	O
(	O
requires	O
Adobe	O
AIR	O
)	O
GPL	B-License
Windows	O
,	O
Mac	O
OS	O
X	O
CompilerEditor	O
less.js-windows	O
Simple	O
command-line	O
utility	O
for	O
Windows	O
that	O
will	O
compile	O
*	O
.less	B-Language
files	O
to	O
CSS	B-Language
using	O
less.js	B-Language
.	O
</s>
