John Collison

stripe-ios. Charge credit cards on iOS 5 using Stripe

wanderlust. Ruby

json. JSON implementation for Ruby

active_merchant. Active Merchant is a simple payment abstraction library used in and sponsored by Shopify. It is written by Tobias Luetke, Cody Fauser, and contributors. The aim of the project is to feel natural to Ruby users and to abstract as many parts as possible away from the user to offer a consistent interface across all supported gateways.

diaspora-project-site. Ruby

4sq-cli. A command line interface to Foursquare