Web Services Interoperability
The Web Services Interoperability Organization (WS-I) is an industry consortium chartered to promote interoperability amongst the stack of web services specifications. WS-I does not define standards for web services; rather, it creates guidelines and tests for interoperability. It has recently become part of OASIS, another standards body.
It is governed by a Board of Directors consisting of the founding members (IBM, Microsoft, BEA Systems, SAP, Oracle, Fujitsu, Hewlett-Packard, and Intel) and two elected members (currently, Sun Microsystems and webMethods). Since joining OASIS, other organizations have joined the WS-I technical committee including CA Technologies, JumpSoft and Booz Allen Hamilton.
The organization's deliverables include profiles, sample applications that demonstrate the profiles' use, and test tools to help determine profile conformance.
WS-I Profiles 
According to WS-I, a profile is
A set of named web services specifications at specific revision levels, together with a set of implementation and interoperability guidelines recommending how the specifications may be used to develop interoperable web services.
WS-I Profile Compliance 
The WS-I is not a certifying authority; thus, every vendor can claim to be compliant to a profile. However the use of the test tool is required before a company can claim a product to be compliant. See WS-I Trademarks and Compliance claims requirements
In a 2003 interview, the WS-I spokesman said even if every companies are free to claim compliance unfaithfully, he expects companies to be honest:
"We expect enforcement of that brand to be market-driven. We suspect no one wants to be the first person to be called on for making a bad claim."