In a recent article from infoworld:
People are finally realizing that Document or Message passing style is the way to go if you want to achieve interoperability in webservices. That’s why I’ve been saying for so long, that the current Web Services specs like WSDL are woefully inadequate and plain wrong. WSDL is modeled after CORBA’s IDL, this assumes RPC style messaging. Furthermore, all the toolkits out there support WSDL based code generation, unfortunately its not that useful for document style messaging.
The problem with the RPC style messaging is that it couples in time the parties involved. In otherwords, the parties have to be both present and active to get the communication across. It’s okay for realtime processes, unfortunately most processes don’t happen in realtime.
The wonderful idea that Linda Spaces (circa. 1980) brought to the world ( JavaSpaces is an implementation of Linda Space) was that it decouples server and client both in space and time. What does decouple in space mean? Well that just means that who communicates to who is not hardwired but discovered dynamically.
So until I see Linda Space mechanisms introduced in the Web Services arena, I’m not going to take it seriously. You can’t just reinvent CORBA with an XML protocol and magically have interoperability. I do agree that XML makes it easier to interoperate by standardizing at least the syntax of messages and providing tools to parse those messages. However, I can’t see what the Web Services protocol stack brings to the table.