In the paper our implementation of a tool for automatic language implementation is presented. From formal language definition LISA 1 produces an interpreter or a compiler for the defined language. In the paper we describe the development of the tool. It is one of the first such tool developed using the object oriented technology and is coded in the C++ programming language. 1. Introduction The development of the first compilers in the late fifties was a very complicated task and lasted very long. For instance the implementation of the compiler for the programming language FORTRAN I took about 18 human years. Later on, some formal methods were developed which made the implementation of the programming languages easier and finally contrib...