It was asked a couple of months ago, but given the AI enshittification, it seems a good time to ask again.

I looked around and found:

  • Pinetta is/was in development but seems dead with no obvious, public code. I am chasing this up on Matrix.
  • Pinry is a FOSS alternative, but not federated, that seems dormant. However, it works and is in Python, so someone could bolt an AP server to it, he says airily.