[computing] An XML-based protocol developed by Microsoft, SAP, and IBM for exchanging information between peers in a decentralized, distributed environment. SOAP allows programs on different computers to communicate independently of an operating system or platform by using the World Wide Web’s Hypertext Transfer Protocol (HTTP) and XML as the basis of information exchange. SOAP is used in Web services and is now a W3C specification. SOAP was originally an acronym for Simple Object Access Protocol, but the acronym has fallen out of use.