x42-Autotune - An autotune implementation in x42 plugin pack
GSnap - With GSnap you can get an auto-tune effect.
CrispyTuner - Fully featured vocal tuning suite.
Revoice Pro - Revoice Pro is an audio plugin used for vocal tuning, time correction and ADR.
Voloco - Auto-tune made simple and funny for everyone
Antares Auto-Tune Pro - Auto-Tune Pro by Antares is the latest and enhanced version of Auto-Tune that offers Auto Mode to correct pitch and Graph Mode for step-by-step modifications of time and pitch.