<s>
Phusion	B-Language
Passenger	I-Language
(	O
informally	O
also	O
known	O
as	O
mod_rails	O
and	O
mod_rack	O
among	O
the	O
Ruby	B-Language
community	O
)	O
is	O
a	O
free	B-Application
web	B-Application
server	I-Application
and	O
application	B-Application
server	I-Application
with	O
support	O
for	O
Ruby	B-Language
,	O
Python	B-Language
and	O
Node.js	B-Language
.	O
</s>
<s>
It	O
is	O
designed	O
to	O
integrate	O
into	O
the	O
Apache	B-Application
HTTP	I-Application
Server	I-Application
or	O
the	O
nginx	B-Operating_System
web	B-Application
server	I-Application
,	O
but	O
also	O
has	O
a	O
mode	O
for	O
running	O
standalone	O
without	O
an	O
external	O
web	B-Application
server	I-Application
.	O
</s>
<s>
Phusion	B-Language
Passenger	I-Language
supports	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
,	O
and	O
is	O
available	O
as	O
a	O
gem	B-Application
package	I-Application
,	O
as	O
a	O
tarball	O
,	O
or	O
as	O
native	O
Linux	O
packages	O
.	O
</s>
<s>
As	O
of	O
Aug	O
2021	O
more	O
than	O
130,000	O
web	O
sites	O
use	O
Phusion	B-Language
Passenger	I-Language
.	O
</s>
<s>
Originally	O
designed	O
for	O
web	O
applications	O
built	O
on	O
the	O
Ruby	B-Application
on	I-Application
Rails	I-Application
framework	O
,	O
it	O
was	O
later	O
extended	O
to	O
support	O
arbitrary	O
Ruby	B-Language
web	O
frameworks	O
through	O
the	B-Application
Rack	I-Application
interface	I-Application
.	O
</s>
<s>
Later	O
versions	O
also	O
added	O
support	O
for	O
Python	B-Language
through	O
the	B-Language
WSGI	I-Language
interface	I-Language
,	O
as	O
well	O
as	O
support	O
for	O
Node.js	B-Language
.	O
</s>
<s>
In	O
2012	O
,	O
Phusion	O
announced	O
,	O
a	O
paid	O
,	O
commercial	O
variant	O
of	O
Phusion	B-Language
Passenger	I-Language
with	O
"	O
a	O
wide	O
array	O
of	O
premium	O
features	O
"	O
.	O
</s>
<s>
Phusion	B-Language
Passenger	I-Language
was	O
the	O
"	O
preferred	O
deployment	O
setup	O
"	O
for	O
Ruby	B-Application
on	I-Application
Rails	I-Application
applications	O
in	O
2016	O
,	O
and	O
has	O
been	O
recommended	O
by	O
the	O
Ruby	B-Application
on	I-Application
Rails	I-Application
authors	O
in	O
2009	O
.	O
</s>
<s>
In	O
2013	O
,	O
in	O
combination	O
with	O
Ruby	B-Language
2.0	O
,	O
or	O
with	O
the	O
now-discontinued	O
,	O
Phusion	B-Language
Passenger	I-Language
claimed	O
that	O
it	O
was	O
capable	O
of	O
reducing	O
Rails	O
's	O
memory	O
consumption	O
by	O
33%	O
as	O
well	O
as	O
increasing	O
its	O
performance	O
.	O
</s>
