Perl modules for geographic calculations

Math::Trig - trigonometry and great circle functions.

GPS::Babel - convert between GPS file formats.

Geo::Formatter - encode/decode lattitude/longitude strings.

Geo::GNIS - parse USGS geographic names data.

Geo::GPX - read/write GPX open GPS data files.

Geo::Horizon - distance to visual horizone.

Geo::IP - estimate lattitude/longitude coordinates for IP addresses.

Geo::Mercator - convert coordinates to flat-projection map.

Geo::Weather - Get weather from weather channel.

Ham::Locator - convert between lattitude/longitude & maidenhead coordinates.

Net::GPSD3 - Interface to a GPSD server on a laptop.

Geo::Google::StaticMap - Google Maps API wrapper

Geo::OSM::Tiles - OpenStreetMap tiles (calculation of the url of an image tile)