Hi guys,

Yes, we have DMR, P25, NXDN, Fusion and D-Star but these are all VHF.

What about something for HF SSB?

Commercial two-way HF radio users have TWELP as a "standard" as is AMBE for VHF.
Both these are proprietary.

What about an Open Source equivalent, maybe even better?

http://FreeDV.org 

David and his team have available a PC app, connect to your SSB rig and you are away.
Also there is an external box the SM1000 so no PC is needed.

I've created a half-duplex repeater (store and retransmit) called "parrot":
http://www.unixservice.com.au/parrot/src/
Parrot17jul2020.zip runs on the unmodified Codec2 library.

Linux Install notes (any Raspberry Pi or clone):
  
  Download and install the Codec2 library
  git clone https://github.com/drowe67/codec2
  cd codec2; mkdir build1; cd build1; cmake ../ ; make install
  Download freebeacon 
  git clone https://github.com/drowe67/freebeacon
  unzip Parrot17jul2020.zip
  cd freebeacon; mkdir build1; cd build1; cmake ../ ; make

  All the options are the same as "freebeacon".

  OK guys, any interest?

BTW: Our Australian ambulances have been equipped with TWELP HF radios
     for the long distances in outback NSW.