Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.
Google Analytics is a free web analytics service that tracks and reports website traffic.
OpenResty is a web platform based on nginx which can run Lua scripts using its LuaJIT engine.
Ruby on Rails is a server-side web application framework written in Ruby under the MIT License.
ShareThis provides free engagement and growth tools (e.g., share buttons, follow buttons, and reaction buttons) for site owners.