We present the capabilities of the scripting language Open PROMOL and its processor. The intention of the language is to pre-program specifications for modifying programs written in a target language. We use its processor either as a tool for developing the stand-alone reusable components or as a “component-from-the-shelf” in generative tools for generating domain specific programs. The processor itself uses the module (lexical analyser and parser) produced by Lex & Yacc as a reusable component. We describe the generation, computation, control, parameterization and gluing capabilities of the language. We compare our approach with the similar approaches known in the literature.