Please note that having the following JBoss 5 context parameter in the web.xml causes a ZipException on JBoss 6:

<context-param>
<param-name>org.jboss.jbossfaces.WAR_BUNDLES_JSF_IMPL</param-name>
<param-value>true</param-value>
</context-param>

The ZipException is as follows:

00:13:50,911 SEVERE [config] Unable to process annotations for url, vfs:/Servers/JBoss/AS/6.x/6.0.0.Final/server/default/deploy/poll.war/WEB-INF/lib/icefaces.jar/META-INF/faces-config.xml. Reason: java.util.zip.ZipException: error in opening zip file
00:13:50,916 SEVERE [config] : java.util.zip.ZipException: error in opening zip file
at java.util.zip.ZipFile.open(Native Method) [:1.6.0_22]
at java.util.zip.ZipFile.<init>(ZipFile.java:114) [:1.6.0_22]
at java.util.jar.JarFile.<init>(JarFile.java:135) [:1.6.0_22]
at sun.net.www.protocol.jar.URLJarFile.<init>(URLJarFile.java:67) [:1.6.0_22]
at sun.net.www.protocol.jar.URLJarFile$1.run(URLJarFile.java:214) [:1.6.0_22]
at java.security.AccessController.doPrivileged(Native Method) [:1.6.0_22]
at sun.net.www.protocol.jar.URLJarFile.retrieve(URLJarFile.java:198) [:1.6.0_22]
at sun.net.www.protocol.jar.URLJarFile.getJarFile(URLJarFile.java:50) [:1.6.0_22]
at sun.net.www.protocol.jar.JarFileFactory.get(JarFileFactory.java:70) [:1.6.0_22]
at sun.net.www.protocol.jar.JarURLConnection.connect(JarURLConnection.java:104) [:1.6.0_22]
at sun.net.www.protocol.jar.JarURLConnection.getJarFile(JarURLConnection.java:71) [:1.6.0_22]
at com.sun.faces.config.AnnotationScanner.processClasspath(AnnotationScanner.java:309) [:2.1.0-SNAPSHOT]
at com.sun.faces.config.AnnotationScanner.getAnnotatedClasses(AnnotationScanner.java:221) [:2.1.0-SNAPSHOT]
at com.sun.faces.config.ConfigManager$AnnotationScanTask.call(ConfigManager.java:768) [:2.1.0-SNAPSHOT]
at com.sun.faces.config.ConfigManager$AnnotationScanTask.call(ConfigManager.java:739) [:2.1.0-SNAPSHOT]
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) [:1.6.0_22]
at java.util.concurrent.FutureTask.run(FutureTask.java:138) [:1.6.0_22]
at com.sun.faces.config.ConfigManager.initialize(ConfigManager.java:332) [:2.1.0-SNAPSHOT]
at com.sun.faces.config.ConfigureListener.contextInitialized(ConfigureListener.java:226) [:2.1.0-SNAPSHOT]
at org.apache.catalina.core.StandardContext.contextListenerStart(StandardContext.java:3369) [:6.0.0.Final]
at org.apache.catalina.core.StandardContext.start(StandardContext.java:3828) [:6.0.0.Final]
at org.jboss.web.tomcat.service.deployers.TomcatDeployment.performDeployInternal(TomcatDeployment.java:294) [:6.0.0.Final]
at org.jboss.web.tomcat.service.deployers.TomcatDeployment.performDeploy(TomcatDeployment.java:146) [:6.0.0.Final]
at org.jboss.web.deployers.AbstractWarDeployment.start(AbstractWarDeployment.java:477) [:6.0.0.Final]
at org.jboss.web.deployers.WebModule.startModule(WebModule.java:118) [:6.0.0.Final]
at org.jboss.web.deployers.WebModule.start(WebModule.java:95) [:6.0.0.Final]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [:1.6.0_22]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) [:1.6.0_22]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) [:1.6.0_22]
at java.lang.reflect.Method.invoke(Method.java:597) [:1.6.0_22]
at org.jboss.mx.interceptor.ReflectedDispatcher.invoke(ReflectedDispatcher.java:157) [:6.0.0.GA]
at org.jboss.mx.server.Invocation.dispatch(Invocation.java:96) [:6.0.0.GA]
at org.jboss.mx.server.Invocation.invoke(Invocation.java:88) [:6.0.0.GA]
at org.jboss.mx.server.AbstractMBeanInvoker.invoke(AbstractMBeanInvoker.java:271) [:6.0.0.GA]
at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:670) [:6.0.0.GA]
at org.jboss.system.microcontainer.ServiceProxy.invoke(ServiceProxy.java:206) [:2.2.0.GA]
at $Proxy41.start(Unknown Source) at org.jboss.system.microcontainer.StartStopLifecycleAction.installAction(StartStopLifecycleAction.java:53) [:2.2.0.GA]
at org.jboss.system.microcontainer.StartStopLifecycleAction.installAction(StartStopLifecycleAction.java:41) [:2.2.0.GA]
at org.jboss.dependency.plugins.action.SimpleControllerContextAction.simpleInstallAction(SimpleControllerContextAction.java:62) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.action.AccessControllerContextAction.install(AccessControllerContextAction.java:71) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractControllerContextActions.install(AbstractControllerContextActions.java:51) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractControllerContext.install(AbstractControllerContext.java:379) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.system.microcontainer.ServiceControllerContext.install(ServiceControllerContext.java:301) [:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.install(AbstractController.java:2044) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.incrementState(AbstractController.java:1083) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.executeOrIncrementStateDirectly(AbstractController.java:1322) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:1246) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:1139) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.install(AbstractController.java:894) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.install(AbstractController.java:641) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.deployers.vfs.deployer.kernel.BeanMetaDataDeployer.deploy(BeanMetaDataDeployer.java:182) [:2.2.0.GA]
at org.jboss.deployers.vfs.deployer.kernel.BeanMetaDataDeployer.deploy(BeanMetaDataDeployer.java:58) [:2.2.0.GA]
at org.jboss.deployers.spi.deployer.helpers.AbstractSimpleRealDeployer.internalDeploy(AbstractSimpleRealDeployer.java:62) [:2.2.0.GA]
at org.jboss.deployers.spi.deployer.helpers.AbstractRealDeployer.deploy(AbstractRealDeployer.java:55) [:2.2.0.GA]
at org.jboss.deployers.plugins.deployers.DeployerWrapper.deploy(DeployerWrapper.java:179) [:2.2.0.GA]
at org.jboss.deployers.plugins.deployers.DeployersImpl.doDeploy(DeployersImpl.java:1832) [:2.2.0.GA]
at org.jboss.deployers.plugins.deployers.DeployersImpl.doInstallParentFirst(DeployersImpl.java:1550) [:2.2.0.GA]
at org.jboss.deployers.plugins.deployers.DeployersImpl.doInstallParentFirst(DeployersImpl.java:1571) [:2.2.0.GA]
at org.jboss.deployers.plugins.deployers.DeployersImpl.install(DeployersImpl.java:1491) [:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractControllerContext.install(AbstractControllerContext.java:379) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.install(AbstractController.java:2044) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.incrementState(AbstractController.java:1083) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.executeOrIncrementStateDirectly(AbstractController.java:1322) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:1246) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:1139) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:939) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:654) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.deployers.plugins.deployers.DeployersImpl.change(DeployersImpl.java:1983) [:2.2.0.GA]
at org.jboss.deployers.plugins.deployers.DeployersImpl.process(DeployersImpl.java:1076) [:2.2.0.GA]
at org.jboss.deployers.plugins.main.MainDeployerImpl.process(MainDeployerImpl.java:679) [:2.2.0.GA]
at org.jboss.system.server.profileservice.deployers.MainDeployerPlugin.process(MainDeployerPlugin.java:106) [:6.0.0.Final]
at org.jboss.profileservice.dependency.ProfileControllerContext$DelegateDeployer.process(ProfileControllerContext.java:143) [:0.2.2]
at org.jboss.profileservice.dependency.ProfileDeployAction.deploy(ProfileDeployAction.java:151) [:0.2.2]
at org.jboss.profileservice.dependency.ProfileDeployAction.installActionInternal(ProfileDeployAction.java:94) [:0.2.2]
at org.jboss.kernel.plugins.dependency.InstallsAwareAction.installAction(InstallsAwareAction.java:54) [jboss-kernel.jar:2.2.0.GA]
at org.jboss.kernel.plugins.dependency.InstallsAwareAction.installAction(InstallsAwareAction.java:42) [jboss-kernel.jar:2.2.0.GA]
at org.jboss.dependency.plugins.action.SimpleControllerContextAction.simpleInstallAction(SimpleControllerContextAction.java:62) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.action.AccessControllerContextAction.install(AccessControllerContextAction.java:71) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractControllerContextActions.install(AbstractControllerContextActions.java:51) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractControllerContext.install(AbstractControllerContext.java:379) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.install(AbstractController.java:2044) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.incrementState(AbstractController.java:1083) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.executeOrIncrementStateDirectly(AbstractController.java:1322) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:1246) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.resolveContexts(AbstractController.java:1139) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:939) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.dependency.plugins.AbstractController.change(AbstractController.java:654) [jboss-dependency.jar:2.2.0.GA]
at org.jboss.profileservice.dependency.ProfileActivationWrapper$BasicProfileActivation.start(ProfileActivationWrapper.java:190) [:0.2.2]
at org.jboss.profileservice.dependency.ProfileActivationWrapper.start(ProfileActivationWrapper.java:87) [:0.2.2]
at org.jboss.profileservice.dependency.ProfileActivationService.activateProfile(ProfileActivationService.java:215) [:0.2.2]
at org.jboss.profileservice.dependency.ProfileActivationService.activate(ProfileActivationService.java:159) [:0.2.2]
at org.jboss.profileservice.bootstrap.AbstractProfileServiceBootstrap.activate(AbstractProfileServiceBootstrap.java:112) [:0.2.2]
at org.jboss.profileservice.resolver.BasicResolverFactory$ProfileResolverFacade.deploy(BasicResolverFactory.java:87) [:0.2.2]
at org.jboss.profileservice.bootstrap.AbstractProfileServiceBootstrap.start(AbstractProfileServiceBootstrap.java:91) [:0.2.2]
at org.jboss.system.server.profileservice.bootstrap.BasicProfileServiceBootstrap.start(BasicProfileServiceBootstrap.java:132) [:6.0.0.Final]
at org.jboss.system.server.profileservice.bootstrap.BasicProfileServiceBootstrap.start(BasicProfileServiceBootstrap.java:56) [:6.0.0.Final]
at org.jboss.bootstrap.impl.base.server.AbstractServer.startBootstraps(AbstractServer.java:827) [jboss-bootstrap-impl-base.jar:2.1.0-alpha-5]
at org.jboss.bootstrap.impl.base.server.AbstractServer$StartServerTask.run(AbstractServer.java:417) [jboss-bootstrap-impl-base.jar:2.1.0-alpha-5]
at java.lang.Thread.run(Thread.java:680) [:1.6.0_22]

Trying to achieve support for JBoss AS 6 stand-alone environments showed an issue with connecting to HornetQ (JMS) in a timely fashion as reported in the following ticket: https://issues.jboss.org/browse/JBAS-8895

Basically an web application gets a chance to start up before all JBoss AS services have been set up.

I was able to find a workaround for the stand-alone case, by connecting to JMS on a spawned thread using the in-place reconnect strategy of the Message Service Client, while the original thread continues to set up JBoss AS. However, by doing this it is undetermined when the actual connection to JMS was successful, leaving a small window for potential errors to occur, though they have not been experienced so far.

The documentation reflecting the current support for JBoss AS 6.0 stand-alone environments can be found at http://wiki.icesoft.com/display/IFEE2/JBoss+AS+6

A follow-up JIRA has been created to address the cluster environment: http://jira.icefaces.org/browse/IPCK-292

Marking this one as FIXED.