AbstractThe implementation of a support system for interactive languages is described, which include a controlling routine, a macro processor, lexical and syntactic analysis routines, semantic actions, error handling and analysis, log and code generation routines. There are also utility programs for generating the state tables for the syntax analysis.By using a structured programming approach these routines have been developed very quickly, but can still be developed and enhanced due to a well‐defined working environment, a simple approach to coding and reasonable internal documentation.