they always start awesome and then degrade because while each individual addition may be awesome (questionable already), the cumulative unstructured addition will have every likelihood of being not awesome by law of entropy
https://github.com/dhamaniasad/awesome-postgres lists BDR which is deprecated according to https://github.com/2ndQuadrant/bdr, and links to https://2ndQuadrant.com/BDR/ for version 2, but this redirects to https://www.enterprisedb.com/ which does not seem to mention BDR at all.
edit: by pure intuition i reached https://www.enterprisedb.com/docs/pgd/latest/ that seems to be the modern incarnation of BDR. It doesn't seem to mention licensing at all, so it's unclear if this thing is still open in any way that matters.