Active Merchant

Ruby library for dealing with credit cards and payment processors and shipping.

Active Merchant is an extraction from the e-commerce system Shopify. Shopify's requirements for a simple and unified API to access dozens of different payment gateways with very different internal APIs was the chief principle in designing the library.

Active Merchant has been in production use since June 2006 and is now used in most modern Ruby applications which deal with financial transactions.

It was developed to for usage in Ruby on Rails web applications and integrates seamlessly as a plugin but it also works excellently as a stand alone library.

http://www.activemerchant.org/