Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
MaxMind is a provider of geolocation and online fraud detection tools.
Ruby on Rails is a server-side web application framework written in Ruby under the MIT License.
A modest JavaScript framework for the HTML you already have.