Freeware Speech Synthesizers

Festival

A freely available complete diphone concatenation and unit selection TTS system.

    http://www.cstr.ed.ac.uk/projects/festival/   (University of Edinburgh)
    http://fife.speech.cs.cmu.edu/festival/   (Carnegie Mellon University)

Festival how-to

    How to compile Festival (Fedora RedHat)

    The Festival Speech Synthesizer -- Emacs Interface

Flite (Festival-lite)

A smaller, faster alternative version of Festival designed for embedded systems and high volume servers.

    http://www.speech.cs.cmu.edu/flite/

Comment: no multi-language support at the moment.

FreeTTS

A speech synthesizer written entirely in Java.

    http://freetts.sourceforge.net/docs/index.php

Comment: Very basic but free version of a java speech engine, written by Sun, based on flite. Still lots of work to make it speak understandable sentences.

GNU Speech

An extensible, text-to-speech package, based on real-time, articulatory, speech-synthesis-by-rules.

    http://www.gnu.org/software/gnuspeech/

Comment: Speech engine under construction. NextStep Version available.

Mbrola

A freely available diphone concatenation system (back end).

    http://tcts.fpms.ac.be/synthesis/mbrola.html

Epos

A rule-driven TTS system primarily designed to serve as a research tool. It suports czech and slovak.

    http://epos.ure.cas.cz/

HTS

HTS is a freely available HMM-based speech synthesis system (back end).

    http://hts.ics.nitech.ac.jp/