Speak  Freely  allows users of a variety of Unix and Unix-
       like workstations equipped with audio  hardware	connected
       by a network to converse, using the audio input and output
       facilities of the workstation to digitise and later recon-
       struct  the  sound and the network to relay sound packets.
       Optional compression is provided,  allowing  conversations
       over  relatively  low-bandwidth	Internet links as well as
       local area networks.

WWW: http://www.speakfreely.org/
     http://www.fourmilab.ch/speakfree/unix/index.html