Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.
cdnjs is a free distributed JS library delivery service.
JSDelivr is a free public CDN for open-source projects. It can serve web files directly from the npm registry and GitHub repositories without any configuration.
Mailchimp is a marketing automation platform and email marketing service.
Ruby on Rails is a server-side web application framework written in Ruby under the MIT License.
UIKit is the framework used for developing iOS applications.