Geo::osm::tiles provides functions for calculating the path to a map tile at openstreetmap out of geographic coordinates. the path of a tile at osm has the form $zoom/$tilex/$tiley.png. the numbering scheme is documented in the osm wiki at http://wiki.openstreetmap.org/wiki/slippy_map_tilenames .

the package also contains the downloadosmtiles script that allows one to conveniently download osm map tiles from a given osm permalink url.