<s>
OWIN	B-Application
(	O
Open	B-Application
Web	I-Application
Interface	I-Application
for	I-Application
.NET	I-Application
)	O
is	O
a	O
standard	O
for	O
an	O
interface	O
between	O
.NET	O
Web	O
applications	O
and	O
Web	O
servers	O
.	O
</s>
<s>
Prior	O
to	O
OWIN	B-Application
,	O
Microsoft	O
's	O
ASP.NET	B-Application
technology	O
was	O
designed	O
on	O
top	O
of	O
IIS	B-Application
,	O
and	O
Web	O
applications	O
could	O
not	O
easily	O
be	O
run	O
on	O
another	O
Web	O
server	O
(	O
although	O
note	O
that	O
despite	O
this	O
the	O
Mono	O
community	O
developed	O
several	O
ASP.NET	B-Application
compatible	O
Web	O
servers	O
,	O
such	O
as	O
XSP	B-Application
)	O
.	O
</s>
<s>
OWIN	B-Application
aims	O
to	O
decouple	O
the	O
relationship	O
between	O
ASP.NET	B-Application
applications	O
and	O
IIS	B-Application
by	O
defining	O
a	O
standard	O
interface	O
.	O
</s>
<s>
Developers	O
of	O
Web	O
servers	O
can	O
be	O
sure	O
that	O
,	O
if	O
they	O
implement	O
OWIN	B-Application
correctly	O
,	O
ASP.NET	B-Application
applications	O
will	O
run	O
on	O
their	O
server	O
.	O
</s>
<s>
Similarly	O
,	O
new	O
Web	B-Application
frameworks	I-Application
could	O
be	O
developed	O
as	O
an	O
alternative	O
to	O
ASP.NET	B-Application
.	O
</s>
<s>
So	O
long	O
as	O
they	O
target	O
OWIN	B-Application
,	O
they	O
will	O
run	O
on	O
any	O
OWIN	B-Application
compatible	O
Web	O
server	O
,	O
including	O
IIS	B-Application
.	O
</s>
<s>
In	O
this	O
regard	O
,	O
OWIN	B-Application
aims	O
to	O
do	O
for	O
.NET	O
what	O
Java	B-Application
Servlet	I-Application
and	O
Servlet	B-Language
containers	I-Language
do	O
for	O
the	O
JVM	B-Language
.	O
</s>
<s>
Project	O
Katana	O
is	O
a	O
set	O
of	O
OWIN	B-Application
components	O
built	O
by	O
Microsoft	O
.	O
</s>
<s>
In	O
addition	O
to	O
decoupling	O
Web	B-Application
frameworks	I-Application
and	O
Web	O
servers	O
,	O
OWIN	B-Application
allows	O
chaining	O
together	O
middleware	B-General_Concept
into	O
a	O
pipeline	O
.	O
</s>
<s>
A	O
Web	B-Application
framework	I-Application
can	O
interact	O
with	O
OWIN	B-Application
without	O
knowing	O
whether	O
it	O
is	O
interacting	O
directly	O
with	O
the	O
underlying	O
web	O
server	O
,	O
or	O
with	O
one	O
or	O
more	O
layers	O
of	O
middleware	B-General_Concept
(	O
each	O
implementing	O
OWIN	B-Application
)	O
on	O
top	O
of	O
the	O
Web	O
server	O
.	O
</s>
<s>
In	O
Project	O
Katana	O
,	O
Microsoft	O
has	O
made	O
into	O
OWIN	B-Application
modules	O
several	O
ASP.NET	B-Application
features	O
that	O
were	O
previously	O
part	O
of	O
the	O
core	O
ASP.NET	B-Application
framework	I-Application
.	O
</s>
<s>
This	O
allows	O
them	O
to	O
be	O
reused	O
in	O
other	O
Web	B-Application
frameworks	I-Application
,	O
and	O
also	O
ensures	O
a	O
cleaner	O
separation	O
from	O
the	O
application	O
using	O
them	O
.	O
</s>
