The Assembly Toolkit (ATK) is a general tool used by several IBM® EJB servers, including CICS, to build JAR files ready for the runtime environment. The Assembly Toolkit for Windows is supplied with WebSphere Application Server Version 5.0 and later. (The Application Assembly Tool (AAT), provided with WebSphere Application Server Version 4 and early copies of WebSphere Application Server Version 5.0, can still be used but is not supported).
For detailed information about using ATK, see the CICS® Operations and Utilities Guide.