<s>
An	O
SWC	O
file	O
is	O
a	O
package	O
of	O
precompiled	B-Language
Flash	B-Operating_System
symbols	O
and	O
ActionScript	B-Operating_System
code	O
that	O
allows	O
a	O
Flash	B-Operating_System
or	O
Flex	B-Operating_System
developer	B-Application
to	O
distribute	O
classes	O
and	O
assets	O
,	O
or	O
to	O
avoid	O
recompiling	O
symbols	O
and	O
code	O
that	O
will	O
not	O
change	O
.	O
</s>
<s>
SWC	O
files	O
can	O
be	O
generated	O
by	O
the	O
Adobe	B-Operating_System
Flash	I-Operating_System
Professional	I-Operating_System
authoring	O
tool	O
,	O
and	O
by	O
Flash	B-Application
Builder	I-Application
(	O
or	O
its	O
companion	O
compiler	B-Language
MXMLC	B-Operating_System
)	O
.	O
</s>
<s>
They	O
are	O
sometimes	O
referred	O
to	O
as	O
class	O
libraries	B-Library
and	O
cannot	O
be	O
directly	O
executed	O
by	O
the	O
Flash	B-Operating_System
Player	I-Operating_System
.	O
</s>
<s>
SWC	O
code	B-Library
libraries	I-Library
are	O
typically	O
included	O
in	O
an	O
ActionScript	B-Operating_System
3	O
project	O
,	O
and	O
compiled	B-Language
into	O
the	O
final	O
SWF	O
file	O
alongside	O
the	O
developer	B-Application
's	O
program	O
,	O
by	O
the	O
ActionScript	B-Operating_System
3	O
compiler	B-Language
.	O
</s>
<s>
A	O
SWC	O
file	O
is	O
compressed	B-General_Concept
by	O
means	O
of	O
the	O
ZIP	B-General_Concept
archive	I-General_Concept
format	O
.	O
</s>
<s>
Renaming	O
the	O
extension	O
of	O
a	O
SWC	O
file	O
to	O
"	O
zip	B-General_Concept
"	O
will	O
allow	O
any	O
ZIP-compatible	O
decompression	B-General_Concept
software	I-General_Concept
to	O
show	O
the	O
contents	O
of	O
the	O
file	O
.	O
</s>
<s>
An	O
uncompressed	B-General_Concept
SWC	O
file	O
contains	O
at	O
least	O
a	O
catalog.xml	O
file	O
,	O
and	O
a	O
SWF	O
file	O
,	O
usually	O
named	O
"	O
library.swf	O
"	O
.	O
</s>
<s>
It	O
may	O
also	O
contain	O
other	O
files	O
,	O
such	O
as	O
CSS	B-Language
files	O
.	O
</s>
<s>
The	O
catalog	O
contains	O
a	O
list	O
of	O
the	O
ActionScript	B-Operating_System
classes	O
contained	O
in	O
the	O
library	B-Library
,	O
their	O
dependencies	O
,	O
and	O
modification	O
dates	O
.	O
</s>
<s>
This	O
is	O
a	O
simple	O
example	O
of	O
a	O
catalog.xml	O
for	O
a	O
SWC	O
created	O
in	O
Flash	B-Operating_System
CS4	O
which	O
contains	O
two	O
sounds	O
.	O
</s>
