I want to create different kinds of processes in which agents interact with each other. I want to describe (define, formalize) processes of interaction between agents using a special language. In other words, I want to provide an environment where agents can interact with each other in a certain way and I want to describe the way of interaction using a programming language which is suited for that. Is there such a language?
To be more specific and less abstract, we can think of agents as users of a web site. The web site evolves depending on action of users (users have a certain freedom to act). What user can do and what happens as a result of their action should be described by the language.