ShockWave Component (SWC)
Filename extension	.swc
Internet media type	application/octet-stream
Magic number	PK\003\004
Developed by	Adobe Systems
Type of format	ClassLibrary
Container for	XMLSWFCSS
Extended from	ZIP

AnSWC file is a package ofprecompiledFlash symbols andActionScriptcode that allows a Flash orFlexdeveloper to distribute classes and assets, or to avoid recompiling symbols and code that will not change.^[1][2] SWC files can be generated by theAdobe Flash Professional authoring tool, and byFlash Builder (or its companion compilerMXMLC).^[3] They are sometimes referred to as classlibraries and cannot be directly executed by theFlash Player.

SWC code libraries are typically included in an ActionScript 3 project, and compiled into the finalSWF file alongside the developer's program, by the ActionScript 3 compiler. Only the classes that have been used by the project (and their dependencies) are transferred into the resulting SWF file.

A SWC file iscompressed by means of theZIP archive format.^[4] Renaming the extension of a SWC file to "zip" will allow any ZIP-compatible decompression software to show the contents of the file.

An uncompressed SWC file contains at least a catalog.xml file, and aSWF file, usually named "library.swf". It may also contain other files, such asCSS files. The catalog contains a list of the ActionScriptclasses contained in the library, their dependencies, and modification dates.

This is a simple example of a catalog.xml for a SWC created inFlash CS4 which contains two sounds.

<?xml version="1.0" encoding="utf-8"?><swcxmlns="http://www.adobe.com/flash/swccatalog/9"><versions><swcversion="1.2"/><flashversion="10.0"build="d566"platform="MAC"/></versions><features><feature-script-deps/><feature-files/></features><libraries><librarypath="library.swf"><scriptname="ButtonClickSound"mod="1275949831598"><defid="ButtonClickSound"/><depid="AS3"type="n"/><depid="flash.media:Sound"type="i"/></script><scriptname="EndGameSound"mod="1275949831598"><defid="EndGameSound"/><depid="AS3"type="n"/><depid="flash.media:Sound"type="i"/></script></library></libraries><files></files></swc>

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