Speak Freely is a Cross Platform Internet telephony (Voice Chat) application which provides high quality voice grade audio with GSM and CELP compression and encryption with DES, Blowfish, and IDEA ciphers.
Refering to recent news: The maintainers will never add any unwanted extra software in the zip download file but we can only speak for our selves.
ViGiL is supposed to be a platform-independent tool for singing students. In it's final version it should be able to analyze a voice recording (read from audio file or microphone) and compare it to a given score according to melody, rhythm and dynamics.
VoiceGuard is a Win32 application that listens to what a speakers speaks into his/her mic and decides whether he/she is an authorised user or not. The system must have a sound card installed.