Linux, but not Open Source, u-he's new synth Repro-5 public beta is now
available. I installed it and give it a quick try for now. Sounds
great. Repro-5 is the Sequential Circuit polyphonic Prophet
synth emulation.
From the KVR thread, first page:
https://www.kvraudio.com/forum/viewtopic.php?f=31&t=494717
Cheers.