<s>
Managed	B-Language
Extensibility	I-Language
Framework	I-Language
(	O
MEF	O
)	O
is	O
a	O
component	O
of	O
.NET	B-Application
Framework	I-Application
4.0	O
aiming	O
to	O
create	O
lightweight	O
,	O
extensible	O
applications	O
.	O
</s>
<s>
It	O
aims	O
to	O
allow	O
.NET	B-Application
application	O
developers	O
to	O
discover	O
and	O
use	O
extensions	O
with	O
no	O
configuration	O
required	O
.	O
</s>
<s>
MEF	O
was	O
introduced	O
as	O
a	O
part	O
of	O
.NET	B-Application
4.0	O
and	O
Silverlight	B-Application
4	I-Application
.	O
</s>
<s>
It	O
was	O
later	O
improved	O
with	O
the	O
release	O
of	O
.NET	B-Application
4.5	O
by	O
adding	O
support	O
for	O
generic	B-Language
types	I-Language
and	O
the	O
introduction	O
of	O
a	O
convention-based	O
extension	O
model	O
.	O
</s>
