Ruby wrapper for the e-conomic SOAP API, that aims at making working with the API bearable. E-conomic is a web-based accounting system. For their marketing speak, see http://www.e-conomic.co.uk/about/. More details about their API at http://www.e-conomic.co.uk/integration/integration-partner/.

SEPA Financial Messages using Web Services

This is a gem used for parsing resumes using the Sovren resume parser service.

Spree extension for providing Tax Cloud services in USA.

Ruby client para los web services de la AFIP

A simple gem to access the DHL Intraship API

Simple, lightweight eBay Trading API Client

A gem to manage F5 BigIP devices using the iControl API

Rails GUS API library based on official REGON SOAP api.

A gem to integrate with the Responsys SOAP API

A gem by TaxJar that can be used to validate VAT IDs

A simple ABN search library for validating and obtaining ABN details from the Australian Business Register.

Baidu Services Pack,including SEM, Map, Ranking and the others

A Ruby client for Bing Ads API that includes a proxy to all Bing Ads API web services and abstracts low level details of authentication with OAuth2.

Bing Ads Reports

Adaptador para el Web Service de Facturacion Electronica de AFIP

Ruby client for the Creditsafe SOAP API

A super easy to use UPnP control point client

Provides an easy-to-use ruby interface into the ExactTarget SOAP API, using the Savon client.

If you got approved for wirking with Russian FNS API, this gem will help you.