A number of fully-tested clients for interacting with all of the available postcode anywhere services, including capture, cleansing, payment validation and email validation

Payment solutions with GMO services

Parsley-Payment.js bundled for Rails Asset Pipeline

Performing multiple payments to PayPal using the MassPay API

PayPal Client.

Payfort Start is the easiest way to accept payments online in the middle east. See https://start.payfort.com for details.

A gem for e-payment systems API's and SCI's

Payzen payment form generator

Integration with Przelewy24 payment gateway.

TPaga Payment Gateway API [Learn about TPaga](https://tpaga.co) [More information about this library] (http://tpaga.co/docs)

I hope to communicate to developers of web apps, especially of those handles payment information, that they should be aware of what they trust when developing an app. This should make the app more secure and make the developers aware of when to update gems or certs.

Use Stellar payment channels in Ruby with ease

Module for Stripe payment functionality in the Trado Ecommerce platform.

Moncash sdk to perform and retieve payment to moncash api

Payment gateway for USA ePay transaction

SlidePay makes it ridiculously easy to take swiped payments anywhere, on any device. Check out http://www.slidepay.com for more info.