WSO2 SOA Enablement Server for Java™ 6.6 is backward compatible with WSO2 SOA Enablement Server for Java 6.0 and 5.5 by default; no backward compatibility components need be installed. If you would like your installation of WSO2 SOA Enablement Server for Java 6.6 to be compatible with version 4.7 of WSO2 SOA Enablement Server for Java you must choose backward compatibility during stand-alone installation. This is a standard option during installation: the WSO2 SOA Enablement Server for Java installer asks if you want backward compatibility installed. You need backward compatibility installed for the following use cases: