During data preprocessing it all comes from the same OSM extract, except for Pelias which also pulls data in from Who's On First, and Planetiler which also pull

During data preprocessing it all comes from the same OSM extract, except for Pelias which also pulls data in from Who's On First, and Planetiler which also pulls data in from Natural Earth (and a few other sources). At runtime tiles are served over the wire but everything else happens server-side. So it's a bit of everything :D