Geo::IP::PurePerl uses a file based database. This database simply contains
IP blocks as keys, and countries as values. This database is more complete
and accurate than reverse DNS lookups.

Geo::IP::PurePerl can be used to automatically select the geographically
closest mirror, to analyze your web server logs to determine the countries
of your visiters, for credit card fraud detection, and for software export
controls.

WWW: https://metacpan.org/release/Geo-IP-PurePerl