VirSyn has released a time-limited, but fully functional demo version of CANTOR 2. It is limited to 20 hours of usage / 30 days and includes more than a dozen demo projects, including the one used to make VirSyn's audio demos. A short tutorial is available to help you to explore the land of vocal synthesis.
NOTE: The demo version of CANTOR 2 requires a Syncrosoft key/dongle. You can use the Syncrosoft dongle which comes with some of the products from Steinberg, Arturia, Korg, etc. or you can purchase one.