Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.
Headroom.js is a JS widget that allows you to react to the user's scroll. The header slides out of view when scrolling down and slides back in when scrolling up.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
PHP is a general-purpose scripting language used for web development.
Zendesk is a cloud-based help desk management solution offering customizable tools to build customer service portal, knowledge base and online communities.