In this thesis the agent programming language GOAL is extended with communication. For GOAL we pur- sue an implementation that has a well-founded theory as well as providing pragmatic programming constructs for the programmer. Existing technologies are reviewed to explore their approaches. Many of these technolo- gies have Speech-act theory as their theoretic base, or build upon other technologies that do so. This led to communication frameworks having vast and unclear performative sets and lacking formal semantics. This thesis goes back to the core of communication by regarding communication from a linguistic perspec- tive. This approach inspires syntactical representation of communication constructs and also leads the way to specifying a formal semantics for those communication constructs. This semantics does not have a receiver of a message refer directly to the mental state of the sender, but rather specifies how a model of that mental state can be deduced from the communication. These mental models are implemented as language constructs which the agent programmer can use to have the agents reason about the beliefs and goals of other agents. Finally the necessary middleware elements are implemented into the GOAL interpreter to allow a system of multiple agents to be distributed across multiple platforms or hosts.