Spree-postcode-zones is a project mainly written in RUBY and JAVASCRIPT, it's free.
Allows Spree Zones to be defined by postcode
= Postcode Zones
Allows Spree zones to be defined by postcode.
Works by matching the first part of the postcode to the input. This allows entire postcode blocks to be specified, or only small parts.
Postcode lists are be defined as comma-separated blocks.