Bayonne - Telephony Server of the GNU Project
   Bayonne is the free multi-line telephony server of the GNU project. Source code available for LINUX/UNIX targeted towards messaging, IVR with considerable extensibility. Bayonne supports a modular architecture, native scripting and TGI.
   http://wiki.gnutelephony.org/

CVoiceControl
   CVoiceControl is a speech recognition system that allows the user to connect spoken commands to Unix commands.
   http://www.kiecza.net/daniel/linux/

Open Mind Speech Project
   Speech recognition project for Linux. Designed so that it can be easily integrated into any application or window manager as well as the KDE and Ggnome desktop environments.
   http://freespeech.sourceforge.net/FreeSpeech/html/

The Festival Speech Synthesis System
   Festival is a general multi-lingual speech synthesis system developed at CSTR. It offers a full text to speech system with various APIs, as well an environment for development and research of speech synthesis techniques.
   http://www.cstr.ed.ac.uk/projects/festival/

The MBROLA Project
   Multi-lingual text to speech synthesis. Free multi platform software download for research purposes.
   http://tcts.fpms.ac.be/synthesis/

Unix Speech Recognition
   Special Synapse TAP Workstation translates speech into mouse events and keystrokes to control all environments - Unix, mainfame, and Mac with speech recognition.
   http://www.unixspeech.com/