<s>
PostCSS	B-Language
is	O
a	O
software	B-Application
development	I-Application
tool	I-Application
that	O
uses	O
JavaScript-based	O
plugins	B-Application
to	O
automate	O
routine	O
CSS	B-Language
operations	O
.	O
</s>
<s>
PostCSS	B-Language
is	O
a	O
framework	B-Architecture
to	O
develop	O
CSS	B-Language
tools	O
.	O
</s>
<s>
It	O
can	O
be	O
used	O
to	O
develop	O
a	O
template	O
language	O
such	O
as	O
Sass	B-Language
and	O
LESS	B-Language
.	O
</s>
<s>
The	O
PostCSS	B-Language
core	O
consists	O
of	O
:	O
</s>
<s>
Features	O
are	O
made	O
available	O
through	O
plugins	B-Application
.	O
</s>
<s>
The	O
plugins	B-Application
are	O
small	O
programs	O
working	O
with	O
the	B-Data_Structure
object	I-Data_Structure
tree	I-Data_Structure
.	O
</s>
<s>
After	O
the	O
core	O
has	O
transformed	O
a	O
CSS	B-Language
string	O
into	O
an	O
object	O
tree	O
,	O
the	O
plugins	B-Application
analyze	O
and	O
change	O
the	O
tree	O
.	O
</s>
<s>
Then	O
PostCSS	B-Language
generates	O
a	O
new	O
CSS	B-Language
string	O
for	O
the	O
plugin-changed	O
tree	O
.	O
</s>
<s>
PostCSS	B-Language
and	O
its	O
plugins	B-Application
are	O
written	O
in	O
JavaScript	B-Language
and	O
distributed	O
through	O
npm	B-Language
,	O
which	O
offer	O
APIs	B-Application
for	O
low-level	O
JavaScript	B-Language
operations	O
.	O
</s>
<s>
There	O
are	O
official	O
tools	O
making	O
it	O
possible	O
to	O
use	O
PostCSS	B-Language
with	O
build	O
systems	O
such	O
as	O
Webpack	B-Language
,	O
Gulp	B-Language
,	O
and	O
Grunt	B-Language
.	O
</s>
<s>
Browserify	B-Language
or	O
Webpack	B-Language
can	O
be	O
used	O
to	O
open	O
PostCSS	B-Language
in	O
a	O
browser	O
.	O
</s>
<s>
PostCSS	B-Language
allows	O
changing	O
the	O
parser	B-Language
and	O
generator	O
.	O
</s>
<s>
In	O
this	O
case	O
,	O
PostCSS	B-Language
could	O
be	O
used	O
to	O
work	O
with	O
the	O
Less	B-Language
and	O
SCSS	B-Language
sources	O
.	O
</s>
<s>
However	O
,	O
PostCSS	B-Language
on	O
its	O
own	O
cannot	O
compile	O
Sass	B-Language
or	O
Less	B-Language
to	O
CSS	B-Language
.	O
</s>
<s>
What	O
it	O
does	O
is	O
change	O
the	O
original	O
files	O
—	O
for	O
instance	O
,	O
by	O
sorting	O
the	O
CSS	B-Language
properties	O
or	O
checking	O
the	O
code	O
for	O
mistakes	O
.	O
</s>
<s>
PostCSS	B-Language
supports	O
SugarSS	O
.	O
</s>
<s>
PostCSS	B-Language
plugins	B-Application
perform	O
different	O
CSS	B-Language
processing	O
tasks	O
ranging	O
from	O
analysis	O
and	O
properties	O
sorting	O
to	O
minification	B-Language
.	O
</s>
<s>
The	O
complete	O
plugin	B-Application
list	O
can	O
be	O
found	O
on	O
postcss.parts	O
,	O
with	O
some	O
examples	O
listed	O
below	O
.	O
</s>
<s>
CSS	B-Language
Modules	O
to	O
get	O
CSS	B-Language
selectors	O
isolated	O
and	O
code	O
organized	O
.	O
</s>
<s>
It	O
is	O
supplied	O
as	O
part	O
of	O
Webpack	B-Language
.	O
</s>
<s>
stylelint	O
to	O
analyze	O
CSS	B-Language
code	O
for	O
mistakes	O
and	O
check	O
style	O
consistency	O
.	O
</s>
<s>
stylefmt	O
fixes	O
the	O
CSS	B-Language
code	O
according	O
to	O
the	O
stylelint	O
settings	O
.	O
</s>
<s>
PreCSS	O
to	O
perform	O
some	O
Sass/Less	O
preprocessing	O
functions	O
.	O
</s>
<s>
postcss-preset-env	O
to	O
emulate	O
features	O
from	O
unfinished	O
CSS	B-Language
specification	O
drafts	O
.	O
</s>
<s>
cssnano	O
to	O
make	O
CSS	B-Language
smaller	O
in	O
size	O
by	O
getting	O
rid	O
of	O
the	O
spaces	O
and	O
rewriting	O
the	O
code	O
.	O
</s>
<s>
RTLCSS	O
to	O
change	O
CSS	B-Language
code	O
so	O
that	O
the	O
design	O
should	O
be	O
suitable	O
for	O
right-to-left	O
writing	O
(	O
such	O
is	O
applied	O
in	O
Arabic	O
and	O
Hebrew	O
)	O
.	O
</s>
<s>
postcss-assets	O
,	O
postcss-inline-svg	O
and	O
postcss-sprites	O
to	O
work	O
with	O
graphics	O
.	O
</s>
<s>
During	O
the	O
course	O
of	O
the	O
Rework	O
project	O
,	O
the	O
idea	O
of	O
modular	O
CSS	B-Language
processing	O
was	O
suggested	O
by	O
TJ	O
Holowaychuk	O
September	O
1	O
,	O
2012	O
.	O
</s>
<s>
March	O
14	O
,	O
2013	O
,	O
Andrey	O
Sitnik	O
's	O
front-end	O
work	O
for	O
Evil	O
Martians	O
resulted	O
in	O
Autoprefixer	O
,	O
a	O
Rework-based	O
plugin	B-Application
.	O
</s>
<s>
Initially	O
,	O
the	O
plugin	B-Application
name	O
was	O
rework-vendors	O
.	O
</s>
<s>
September	O
7	O
,	O
2013	O
,	O
Andrey	O
Sitnik	O
started	O
to	O
develop	O
PostCSS	B-Language
based	O
on	O
the	O
Rework	O
ideas	O
.	O
</s>
<s>
In	O
3	O
months	O
,	O
the	O
first	O
PostCSS	B-Language
plugin	B-Application
,	O
grunt-pixrem	O
was	O
released	O
.	O
</s>
<s>
December	O
22	O
,	O
2013	O
,	O
Autoprefixer	O
version	O
1.0	O
migrated	O
to	O
PostCSS	B-Language
.	O
</s>
<s>
For	O
PostCSS	B-Language
,	O
the	O
primary	O
style	O
focus	O
is	O
alchemy	B-Language
.	O
</s>
<s>
Major	O
and	O
minor	O
PostCSS	B-Language
versions	O
get	O
their	O
names	O
after	O
the	O
Ars	B-Application
Goetia	I-Application
demons	O
.	O
</s>
<s>
The	O
PostCSS	B-Language
team	O
used	O
the	O
term	O
to	O
show	O
that	O
PostCSS	B-Language
was	O
not	O
a	O
template	O
language	O
(	O
preprocessor	O
)	O
but	O
a	O
CSS	B-Language
tool	O
.	O
</s>
<s>
Now	O
,	O
instead	O
of	O
postprocessor	O
,	O
the	O
PostCSS	B-Language
team	O
use	O
the	O
term	O
processor	O
.	O
</s>
