Accepting iDEAL, Bancontact, SOFORT Banking, Creditcard, SEPA Bank transfer, SEPA Direct debit, PayPal, KBC Payment Button, CBC Payment Button, Belfius Direct Net, paysafecard, PODIUM Cadeaukaart and ING Home’Pay online payments without fixed monthly costs or any punishing registration procedures.'

Authorize.Net SDK includes standard payments, recurring billing, and customer profiles

Additional Payment Gateways for Solidus

PAY.JP makes it way easier and less expensive to accept payments.

Amazon Payments - Login and Pay with Amazon Ruby SDK

To award loyalty points and add loyalty points payment method to spree

Accepts orders via http, returns payment info via http or streams updates via websockets, stores orders in a DB

Easy online payments with eWAY and the eWAY Rapid Ruby gem.

Spreedly is a cloud service that allows you to store credit cards and run transactions against them, enabling you to accept payments on your website while avoiding all liability and PCI compliance requirements.

A Ruby gem wrapper for the pin-payments (pinpayments.com) API

Robokassa is payment system, that provides a single simple interface for payment systems popular in Russia. If you have customers in Russia you can use the gem. The first thing about this gem, is that it was oribinally designed for spree commerce. So keep it in mind.

Quickly build an online store with carts, orders, automatic email receipts and payment collection via Stripe, StripeConnect, PayPal and Moneris.

Experimental library for working with GoogleCheckout. Currently in use for payment at http://peepcode.com.

This is a Ruby library for integrating with SagePay. SagePay is a payment gateway for accepting credit card payments through your web app.

A straight-forward REST API for Amazon's Flexible Payments Services.

Drop Zone is a solution to the problem of restricted sales in censored markets. The proposal is for the design of a protocol and reference client that encodes the location and a brief description of a good onto The Blockchain. Those wishing to purchase the good can search for items within a user-requested radius. Sellers list a good as available within a geographic region, subject to some degree of precision, for the purpose of obfuscating their precise location. Goods are announced next to an expiration, a hashtag, and if space permits, a description. Once a buyer finds a good in a defined relative proximity, a secure communication channel is opened between the parties on the Bitcoin test network ("testnet"). Once negotiations are complete, the buyer sends payment to the seller via the address listed on the Bitcoin mainnet. This spend action establishes reputation for the buyer, and potentially for the seller. Once paid, the seller is to furnish the exact GPS coordinates of the good to the buyer (alongside a small note such as "Check in the crevice of the tree"). When the buyer successfully picks up the item at the specified location, the buyer then issues a receipt with a note by spending flake to the address of the original post. In this way, sellers receive a reputation score. The solution is akin to that of Craigslist.org or Uber, but is distributed and as such provides nearly risk-free terms to contraband sellers, and drastically reduced risk to contraband buyers.

Launch a landing page on Heroku in less than 10 minutes with JohnHenry. This gem sets up bootstrap and provides Bootstrapped user management pages with Devise. JohnHenry also includes a payment form that works with Stripe and is ready to go immediately.

A rails plugin to add active_merchant patch for Taiwan payment

Experimental library for working with GoogleCheckout. Currently in use for payment at http://peepcode.com.

iDEAL payment gateway (see http://www.ideal.nl and http://www.activemerchant.org/)