Your point that xml-rpc was subsetted from SOAP is really interesting; it's definitely different from the widespread perception. I'll leave arguing the point to those who were there. But even if "openness" was added post-facto to SOAP, and xml-rpc is not itself entirely open (though Dave is flirting with open source), the fact is that SOAP and xml-rpc do enable bottom up provisioning of decentralized web services. I believe that one key to open source (considered most broadly) is an architecture that allows any developer to come to the table as an equal participant. I do see people starting to build web services in the same way they built utilities for UNIX/Linux or built web sites. And that's really important! If anyone can easily add services that work together, we really can build a bottom-up internet operating system.
