Book excerpt: A class of emitter augmented phrase structure grammars is defined which can specify simple translations of context free languages. A self-translating metatranslator for the description of these translation grammars is described. Several mutually recursive functions define an interpreter which will execute grammars as translated by this metatranslator. The evolution of more sophisticated translations systems is discussed and extensions to the metatranslator and interpreter are demonstrated. A very concise self-describing metalanguage and an interpreter which will directly execute its self-description are presented. (Author).