<s>
The	O
Windows	B-Application
Communication	I-Application
Foundation	I-Application
(	O
WCF	O
)	O
,	O
previously	O
known	O
as	O
Indigo	B-Application
,	O
is	O
a	O
free	B-License
and	I-License
open-source	I-License
runtime	B-Device
and	O
a	O
set	O
of	O
APIs	B-Application
in	O
the	O
.NET	B-Application
Framework	I-Application
for	O
building	O
connected	O
,	O
service-oriented	O
applications	O
.	O
</s>
<s>
.NET	B-Application
Core	I-Application
1.0	I-Application
,	O
released	O
2016	O
,	O
did	O
not	O
support	O
WCF	O
server	O
side	O
code	O
.	O
</s>
<s>
WCF	O
support	O
was	O
added	O
to	O
the	O
platform	O
with	O
support	O
for	O
.NET	B-Application
Core	I-Application
3.1	I-Application
,	O
.NET	B-Application
5	I-Application
,	O
and	O
.NET	B-Application
6	I-Application
in	O
2022	O
.	O
</s>
<s>
It	O
is	O
designed	O
using	O
service-oriented	O
architecture	O
principles	O
to	O
support	O
distributed	B-Architecture
computing	I-Architecture
where	O
services	O
have	O
remote	O
consumers	B-Protocol
.	O
</s>
<s>
Services	O
are	O
loosely	B-Application
coupled	I-Application
to	O
each	O
other	O
.	O
</s>
<s>
Services	O
typically	O
have	O
a	O
WSDL	O
interface	B-Application
(	O
Web	O
Services	O
Description	O
Language	O
)	O
that	O
any	O
WCF	O
client	O
can	O
use	O
to	O
consume	O
the	O
service	O
,	O
regardless	O
of	O
which	O
platform	O
the	O
service	O
is	O
hosted	O
on	O
.	O
</s>
<s>
With	O
the	O
release	O
of	O
.NET	B-Application
Framework	I-Application
4.0	O
,	O
WCF	O
also	O
provides	O
RSS	O
Syndication	O
Services	O
,	O
WS-Discovery	O
,	O
routing	O
and	O
better	O
support	O
for	O
REST	B-Protocol
services	O
.	O
</s>
<s>
A	O
WCF	O
client	O
connects	O
to	O
a	O
WCF	O
service	O
via	O
an	O
endpoint	B-Protocol
.	O
</s>
<s>
An	O
endpoint	B-Protocol
has	O
an	O
address	B-Protocol
(	O
which	O
is	O
a	O
URL	O
specifying	O
where	O
the	O
endpoint	B-Protocol
can	O
be	O
accessed	O
)	O
and	O
binding	B-Operating_System
properties	O
that	O
specify	O
how	O
the	O
data	O
will	O
be	O
transferred	O
.	O
</s>
<s>
The	O
mnemonic	O
"	O
ABC	O
"	O
can	O
be	O
used	O
to	O
remember	O
address/binding/contract	O
.	O
</s>
<s>
Binding	B-Operating_System
specifies	O
what	O
communication	O
protocols	O
are	O
used	O
to	O
access	O
the	O
service	O
,	O
whether	O
security	O
mechanisms	O
are	O
to	O
be	O
used	O
,	O
and	O
the	O
like	O
.	O
</s>
<s>
WCF	O
includes	O
predefined	O
bindings	O
for	O
most	O
common	O
communication	O
protocols	O
such	O
as	O
SOAP	B-Application
over	O
HTTP	B-Protocol
,	O
SOAP	B-Application
over	O
TCP	O
,	O
and	O
SOAP	B-Application
over	O
Message	O
Queues	O
,	O
etc	O
.	O
</s>
<s>
Interaction	O
between	O
WCF	O
endpoint	B-Protocol
and	O
client	O
is	O
done	O
using	O
a	O
SOAP	B-Application
envelope	O
.	O
</s>
<s>
SOAP	B-Application
envelopes	O
are	O
in	O
simple	O
XML	O
form	O
,	O
which	O
makes	O
WCF	O
platform-independent	O
.	O
</s>
<s>
When	O
a	O
client	O
wants	O
to	O
access	O
the	O
service	O
via	O
an	O
endpoint	B-Protocol
,	O
it	O
not	O
only	O
needs	O
to	O
know	O
the	O
contract	O
,	O
but	O
it	O
also	O
has	O
to	O
adhere	O
to	O
the	O
binding	B-Operating_System
specified	O
by	O
the	O
endpoint	B-Protocol
.	O
</s>
<s>
With	O
the	O
release	O
of	O
the	O
.NET	B-Application
Framework	I-Application
3.5	O
in	O
November	O
2007	O
,	O
Microsoft	O
released	O
an	O
encoder	O
that	O
added	O
support	O
for	O
the	O
JSON	B-General_Concept
serialization	B-Application
format	O
to	O
WCF	O
.	O
</s>
<s>
Behaviors	O
implement	O
the	O
IServiceBehavior	O
interface	B-Application
for	O
service	O
extensions	O
,	O
the	O
IEndpointBehavior	O
for	O
endpoints	O
,	O
the	O
IContractBehavior	O
interface	B-Application
for	O
service	O
contracts	O
,	O
or	O
the	O
IOperationBehavior	O
for	O
operations	O
.	O
</s>
<s>
WCF	O
supports	O
interoperability	O
with	O
WCF	O
applications	O
running	O
on	O
the	O
same	O
Windows	B-Application
machine	O
or	O
WCF	O
running	O
on	O
a	O
different	O
Windows	B-Application
machines	O
or	O
standard	O
Web	O
services	O
built	O
on	O
platforms	O
such	O
as	O
Java	B-Device
running	O
on	O
Windows	B-Application
or	O
other	O
operating	O
systems	O
.	O
</s>
<s>
In	O
addition	O
to	O
SOAP	B-Application
,	O
WCF	O
4	O
supports	O
non-SOAP	O
XML	O
,	O
RSS	O
,	O
JSON	B-General_Concept
,	O
and	O
binary	O
formats	O
for	O
external	O
communication	O
via	O
HTTP	B-Protocol
or	O
HTTPS	B-Protocol
.	O
</s>
