<s>
The	O
Framework	B-Library
Class	I-Library
Library	I-Library
(	O
FCL	O
)	O
is	O
a	O
component	O
of	O
Microsoft	B-Application
's	I-Application
.NET	I-Application
Framework	I-Application
,	O
the	O
first	O
implementation	O
of	O
the	O
Common	O
Language	O
Infrastructure	O
(	O
CLI	O
)	O
.	O
</s>
<s>
In	O
much	O
the	O
same	O
way	O
as	O
Common	O
Language	O
Runtime	O
(	O
CLR	O
)	O
implements	O
the	O
CLI	O
Virtual	B-General_Concept
Execution	I-General_Concept
System	I-General_Concept
(	O
VES	O
)	O
,	O
the	O
FCL	O
implements	O
the	O
CLI	O
foundational	O
Standard	O
Libraries	O
.	O
</s>
<s>
As	O
a	O
CLI	O
foundational	O
class	O
libraries	O
implementation	O
,	O
it	O
is	O
a	O
collection	O
of	O
reusable	O
classes	O
,	O
interfaces	B-Application
,	O
and	O
value	O
types	O
,	O
and	O
includes	O
an	O
implementation	O
of	O
the	O
CLI	O
Base	O
Class	O
Library	O
(	O
BCL	O
)	O
.	O
</s>
<s>
With	O
Microsoft	O
's	O
move	O
to	O
.NET	B-Application
Core	I-Application
,	O
the	O
CLI	O
foundational	O
class	O
libraries	O
implementation	O
is	O
known	O
as	O
CoreFX	O
instead	O
of	O
Framework	B-Library
Class	I-Library
Library	I-Library
.	O
</s>
