In the early nineties, the Institute of Phonetics, Faculty of Arts, Charles University, Prague, and the Institute of Radio-Engineering and Electronics, Academy of Sciences, Prague, had managed to assemble a complete TTS implementation for the Czech and Slovak languages, using a linear prediction based diphone synthesis. This TTS engine then served as a base for further research in speech synthesis, until the source became too large and complicated to be easily modified, ported to new hardware or operating system, or to be well understood by anybody except the authors. By the end of 1995, when a need for testing some new prosody modelling hypotheses had arisen, these limitations were slowly becoming a major burden. A new implementation of part of the system was eventually written from scratch (starting in 1996) and it is still expanding, integrating the original results with numerous recent improvements. It has been baptized Epos in 1998. Our primary design goal is to allow the user the ultimate control over the TTS processing. We avoid hard-wired constants; we use configuration options instead, with sensible default values. Most of the language-dependent processing is driven by a for additional introductory information or ask the authors by . Meanwhile, tell us what kind of introductory information you would like to see here. The documentation is provided for you and we need your feedback.