An interactive environment for developing applications and conducting research in the domain of text-to-speech conversion has been designed. The system is implemented in Prolog and is a new generation of the subclass of speech synthesis-by-rule systems, called rule compilers. It integrates different levels of linguistic and acoustic analyses and is constructed specifically for linguists and phoneticians. Special notational formalisms have been devised, which as closely as possible correspond to phonetic and linguistic terminology. Two types of synthesis strategies are included in the system, the formant synthesis and the polyphone synthesis, i.e., concatenation of speech units of arbitrary size. In the present paper it is shown how this system can be used for implementing a text-to-speech synthesis for Swedish.