Open Source IM and voice client using Jabber and SIP protocols, with great audio quality thanks to speex and a nice and clean interface. Programmed in Java and C++. It supports chat, voice and file transfers.
GNU/Shoes is a wrapper for the Sox audio utility. Written in Perl for Linux and Win32, GNU/Shoes aids the tedious process of converting large numbers of audio files, and provides Jabber messages to notify the user that a batch is complete.