[bdon]

I see, I think that's a good approach to enable serving with stock nginx as well as for companies that are built on Nginx or a plain HTTP serving stack already.

For PMTiles the module is loadable directly as a Caddy plugin (https://docs.protomaps.com/deploy/server#caddyfile) which I prefer to nginx for security and bugs (and automatic SSL), and also enables serving PMTiles from disk or a remote storage bucket without a separate service running.

[hyperknot]

Yes, PMTiles with the Caddy plugin is very similar to nginx + Btrfs.

At that point, the difference between the two projects is mostly which schema is being used.