Which is also available programatically via the java.lang.Package info of org.jboss: // Package information for org.jboss Package jbossPackage = Package.getPackage("org.jboss"); System.out.println("JBoss " + jbossPackage.getImplementationVersion()); This includes the scm tag and build date. If you want the simple version string, use the getSpecificationVersion() method. The jdk extcheck dumps out the version header info of a jar: [starksm@succubus bin]$ extcheck -verbose run.jar Target file:run.jar Specification title:JBossAS Specification version:5.0.0.Beta3 Specification vendor:JBoss (http://www.jboss.org/) Implementation version:5.0.0.Beta3 (build: SVNTag=JBoss_5_0_0_Beta3 date=200705030927) Implementation vendor:JBoss.org Comparing with file:/usr/java/jdk1.5.0_09/jre/lib/ext/sunjce_provider.jar Comparing with file:/usr/java/jdk1.5.0_09/jre/lib/ext/dnsns.jar Comparing with file:/usr/java/jdk1.5.0_09/jre/lib/ext/localedata.jar No conflicting installed jar found. Ian Springer wrote: