Web Services is all about interoperability. Synodinos has written a nice blog about JAX-WS RI - Metro Core and NuSOAP (SOAP PHP toolkit) interoperability.

JAX-WS RI brings in core interoperability, such as WS-I BP 1.1, AP 1.0 and SSBP 1.0 in to Metro stack. This ensures interoperability interoperability in the web services description (WSDL/XML Schema) and also SOAP wire level protocol. We have verified interoperability for the basic web services with various other stacks such as .NET 2.0/3.0, Axis, Xfire etc.

Metro also bring in the advanced web services, such as message level security(Ws-Security), quality of service(WS-RM), brokered trust(WS-Trust/WS-Secure Conversation) through WSIT which are fully tested to be .NET 3.0 interoperable.

In summary use Metro and get a comprehensive interoperability. Keep sending us your feedback at Metro forum or the user alias.