Apache is a free and open-source cross-platform web server software.
Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.
Google Tag Manager is a tag management system (TMS) that allows you to quickly and easily update measurement codes and related code fragments collectively known as tags on your website or mobile app.
Open Graph is a protocol that is used to integrate any web page into the social graph.
PHP is a general-purpose scripting language used for web development.
Select2 is a jQuery based replacement for select boxes. It supports searching, remote data sets, and infinite scrolling of results.