In computer science, message passing programming, as opposed to imperative programming, is a programming paradigm that describes computation in terms of communicating messages among senders and recipients that have local state as opposed to operations that change a global state. Prominent examples of the message passing approach are the Actor model, Process calculi, Web Services, and the Internet. Wikibooks Wikiversity has more about this subject: School of Computer Science Open Directory Project: Computer Science Collection of Computer Science Bibliographies Belief that title science in computer science is inappropriate Categories: Computer science | Academic disciplines ... In computer science, imperative programming, as opposed to declarative programming, is a programming paradigm that describes computation in terms of a program state and statements that change the program state. ... A programming paradigm is a paradigmatic style of programming (compare with a methodology which is a paradigmatic style of doing software engineering). ... Message passing is a style of parallel programming where instead of using shared memory and locks or other facilities of mutual exclusion, different threads of execution communicate via passing messages. ... In computer science, the Actor model, first published in 1973, is a mathematical model of concurrent computation developed by Carl Hewitt and his students and colleagues at CalTech, Kyoto University, MCC, MIT, SRI, Stanford University, University of Illinois, University of Paris 6, University of Pisa, University of Tokyo and elsewhere. ... In the first half of the 20th century, various formalisms were proposed to capture the informal concept of computable function, μ-recursive functions, Turing Machines and the λ-calculus possibly being the most well-known examples today. ... A web service is a collection of protocols and standards used for exchanging data between applications. ...