VirtualMIDISynth - VirtualMIDISynth is a software MIDI synthesizer implemented as a Windows multimedia user driver...
GSnap - With GSnap you can get an auto-tune effect.
Virtual MIDI Piano Keyboard - Virtual MIDI Piano Keyboard is a MIDI events generator and receiver.
Revoice Pro - Revoice Pro is an audio plugin used for vocal tuning, time correction and ADR.
EveryonePiano - Everyone Piano is the best free computer keyboard piano software, which supports downloading 3 types of music score formats like stave, right and left hand numbered musical notation and EOP file.
Celemony Melodyne - Celemony Melodyne is the perfect quick and easy tool for all your tuning needs.