The verifier tool checks a Java EE application file, including Java classes and deployment descriptors, for compliance with Java EE specifications. Java EE application files are Java archive (JAR), web archive (WAR), resource adapter archive (RAR), or enterprise archive (EAR) files. Use the verifier tool to check whether an application complies with the Java EE specification and to make applications portable across application servers. The verifier tool can be launched from the command line. For more information, see The verifier Utility in Sun GlassFish Enterprise Server 2.1 Application Deployment Guide.