ASTROGEN (Aggregated deep and Surface naTuRal language GENerator) is a Natural Language Generator written in Prolog. Which hopefully can be used by almost anybody. ASTROGEN has been used for generation of natural language (English) from formal specifications and STEP/EXPRESS Specifications. ASTROGEN consists basically of two modules the Deep and the Surface generator. ASTROGEN was written originally for generating Natural Language from formal specifications for the telecom domain.