All data contributed by Rodnik.today users is in the public domain.
Rodnik.today contains data from OpenStreetMap, which is licensed under the ODbL. In the exports, this data is marked with the osm_* prefix.
All other data is in the public domain. You are free to include it in your own projects and databases, even without mentioning Rodnik.today. (Although it would be nice.)
These links always redirect to the most recent export, so you can use them in scripts and integrations without looking up a fresh link on this page.