The Web Services Interoperability Organization (WS-I) was an industry consortium created in 2002 and chartered to promote interoperability amongst the stack of web services specifications. WS-I did not define standards for web services; rather, it created guidelines and tests for interoperability. In July 2010, WS-I joined the OASIS, standardization consortium as a member section.^[1] It operated until December 2017.^[2] The WS-I standards were then maintained by relevant technical committees within OASIS.

The neutrality of this article is disputed. (February 2021)

It was 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 (Sun Microsystems and webMethods). After it joined OASIS, other organizations have joined the WS-I technical committee including CA Technologies, JumpSoft and Booz Allen Hamilton.

The organization's deliverables included profiles, sample applications that demonstrate the profiles' use, and test tools to help determine profile conformance.

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 Basic Profile
• WS-I Basic Security Profile
• Simple Soap Binding Profile

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 Archived 2013-06-08 at the Wayback Machine

• Web Services Resource Framework
• OASIS