The WS-I Basic Profile v1.1 provides guidance for using SOAP 1.1, WSDL 1.1, and UDDI 2.0. The WS-I Basic Profile group is currently working on two new versions of the profile. WS-I Basic Profile v1.2 (now available as an Approved Working Draft) profiles SOAP 1.1, WSDL 1.1, UDDI 2.0, WS-Addressing 1,0, and MTOM. WS-I Basic Profile v2.0 (now available as a working draft) provides guidance for using SOAP 1.2, WSDL 1.1, UDDI 2.0, WS-Addressing, and MTOM.
WS-I develops profiles based on experience using various specifications together and interoperability testing among various implementations of the specification. To date, very few vendors implement support for WSDL 2.0, so it's difficult to gain the experience necessary to create a profile for it. I suspect that WS-I will launch an effort to define a profile including WSDL 2.0 after products become available and people start using it.
WSDL 2.0 provides a better model for describing RESTful services than WSDL 1.1; therefore, organizations that are developing RESTful services have a compelling reason to adopt WSDL 2.0. But given the limited support for WSDL 2.0 and the untested interoperability situation, I recommend that they also describe their services using WSDL 1.1 to enable interoperability. They might also consider using WADL to describe their RESTful services rather than WSDL 2.0.
This was first published in April 2008