Date: May. 8, 2000
Link: http://www.w3.org/TR/SOAP/
Source Author or Organization: Microsoft, Developmentor, UserLand Software, Inc., IBM, Lotus Development Corporation

SOAP is an XML based object protocol for the exchange of information in a decentralized, distributed environment. It consists of: an envelope that defines a framework for describing what is in a message and how to process it, a set of encoding rules for expressing instances of application-defined datatypes, and a convention for representing remote procedure calls and responses. All encoding is in XML.

SOAP can be described as a high-level way for machines to tell other machines to do things over the internet. It increases interoperability by enabling scripted web applications to cross operating system boundaries, for example connecting desktop tools to powerful content management and collaborative systems running on servers.