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.
Facebook pixel is an analytics tool that allows you to measure the effectiveness of your advertising.
Gravatar is a service for providing globally unique avatars.
Open Graph is a protocol that is used to integrate any web page into the social graph.
W3 Total Cache (W3TC) improves the SEO and increases website performance and reducing load times by leveraging features like content delivery network (CDN) integration and the latest best practices.
WooCommerce is an open-source ecommerce plugin for WordPress.