Hi!
Let me quickly introduce myself before i start with my actual topic: I fell in love with Tempest back in the Jaguar days, and am still a fan til today (along with all other Llamasoft spinoffs that were released over the years, i even did my own variant in 96k some years ago...
From my understanding, the Nuance 0.5.0 Source was placed online by DSI back in January 2008 after developer Mike "Riff" Perry passed away. Unfortunately, the 0.5.1 source, which would have been the most recent, was lost.
As for the VM Labs Authentication tools, the binaries and source code...