<s>
Yarn	B-Language
is	O
one	O
of	O
the	O
main	O
JavaScript	B-Language
package	B-Application
managers	I-Application
,	O
developed	O
in	O
2016	O
by	O
Meta	O
(	O
formerly	O
Facebook	O
)	O
for	O
the	O
Node.js	B-Language
JavaScript	B-Language
runtime	O
environment	O
.	O
</s>
<s>
An	O
alternative	O
to	O
the	O
npm	B-Language
package	B-Application
manager	I-Application
,	O
Yarn	B-Language
was	O
created	O
as	O
a	O
collaboration	O
of	O
Facebook	O
,	O
Exponent	O
(	O
now	O
Expo.dev	O
)	O
,	O
Google	B-Application
,	O
and	O
Tilde	O
(	O
the	O
company	O
behind	O
Ember.js	B-Language
)	O
to	O
solve	O
consistency	O
,	O
security	O
,	O
and	O
performance	O
problems	O
with	O
large	O
codebases	O
.	O
</s>
<s>
Users	O
can	O
write	O
their	O
own	O
plugins	O
for	O
Yarn	B-Language
.	O
</s>
<s>
Yarn	B-Language
constraints	O
allow	O
users	O
to	O
enforce	O
rules	O
for	O
their	O
dependencies	O
or	O
manifest	O
fields	O
across	O
scoped	O
workspaces	O
.	O
</s>
<s>
This	O
feature	O
is	O
aimed	O
to	O
fix	O
an	O
unwell	O
structured	O
node_modules	O
architecture	O
and	O
resulting	O
in	O
a	O
faster	O
Node.js	B-Language
application	O
start-up	O
time	O
.	O
</s>
<s>
Plugins	O
can	O
add	O
new	O
resolvers	O
,	O
fetchers	O
,	O
linkers	O
,	O
commands	O
,	O
and	O
can	O
also	O
register	O
to	O
some	O
events	O
or	O
be	O
integrated	O
with	O
each	O
other	O
,	O
most	O
features	O
of	O
Yarn	B-Language
are	O
implemented	O
through	O
plugins	O
,	O
including	O
yarn	B-Language
add	O
and	O
yarn	B-Language
install	O
,	O
which	O
are	O
also	O
preinstalled	O
plugins	O
.	O
</s>
<s>
Release	O
Workflow	O
automatically	O
upgrades	O
relative	O
packages	O
among	O
monorepos	B-General_Concept
workspaces	O
when	O
root	O
packages	O
are	O
upgraded	O
.	O
</s>
<s>
Yarn	B-Language
can	O
install	O
packages	O
from	O
local	O
cache	O
.	O
</s>
<s>
Yarn	B-Language
binds	O
versions	O
of	O
the	O
package	O
strongly	O
.	O
</s>
<s>
Yarn	B-Language
uses	O
checksum	O
for	O
ensuring	O
data	O
integrity	O
,	O
while	O
npm	B-Language
uses	O
SHA-512	O
to	O
check	O
data	O
integrity	O
of	O
the	O
packages	O
downloaded	O
.	O
</s>
<s>
Yarn	B-Language
installs	O
packages	O
in	O
parallel	O
,	O
while	O
npm	B-Language
installs	O
one	O
package	O
at	O
a	O
time	O
.	O
</s>
<s>
To	O
install	O
yarn	B-Language
:	O
</s>
<s>
To	O
install	O
a	O
package	O
with	O
yarn	B-Language
:	O
</s>
