So I had the same issue as Charlie. I have the orginal Music Port and my XP computer that was running a beta version of the Autonomic software died. I replaced the hard drive and installed Windows 8.1, and had no luck loading the software back. I emailed Autonomic for a copy of the program that was compatible with Win 8.1 or 10 and they didn't give me the time of day.
So I looked at a couple options to be able to use the Nuvo multi-zone amp but still have access to streaming sources. I thought of getting a Sonos Connect and hooking it into a Nuvo input. While this would give me all the modern streaming services, the control would be awkward. I would have to turn on the zones and control the volume at the keypads, then start the Sonos using its app. I had never been able to get the Nuvo (or Autonomics) app to work for me, so I didn't even have the option of using two apps.
So after some research, I decided on a CasaTunes CT-1. It provides one source of streaming services and local music. Controllable through a pretty decent app. The best part is it can also control the Nuvo! I have full control in the CasaTunes app over power, volume, transport, etc for each zone. In addition, it provides metadata at the keypad. All in all, probably the best solution I could find that allowed me to reuse the Essentia and still get streaming support. The Music Port still acts as the NuvoNet translator, but its hooked to the CT-1 now instead of a computer.
--Jamie