Look up sales tax rates by zip code.

Similar interface to "send_file" of Rails.

Currently supports PDF and ZIP files

code,tfile,pager,http,logistic,pay,tmagick,class_extend,aes,rsa,ftp_tool,translate,zip_tool,sql,backup,collection;

Tool (wrapper) for compression and handling multiple type of archives (Zip, GZip, RAR, 7z)

Adds a custom CSV and ZIP renderer to Rails applications

API wrapper for postcodeapi.nu zipcode api

API Testing Done Right

For example, 8840 means 08840 and 5011234 means 00501-1234.

ruby wrapper gem to find the details using Google API

NLP related tools and classes

Convert to alphabet slug from japanese

you can search address by zipcode

Brazilian zipcode validations for ActiveRecord, integrated with correios-cep gem.

Gem to identify zip codes inside Japan

Resolve a postal (ZIP) code to a corresponding city or state.

Gem to search plants by zip code which grow well in a user's area.

rubyzip is a ruby module for reading and writing zip files.

Get NYC neighborhood names by ZIP code

Add address fields to a DataMapper model. This includes optional validations, and additional DM types for ZipCode and PhoneNumber.