Apache is a free and open-source cross-platform web server software.
Constant Contact is a marketing automation and email marketing solution.
Facebook pixel is an analytics tool that allows you to measure the effectiveness of your advertising.
Google Hosted Libraries is a stable, reliable, high-speed, globally available content distribution network for the most popular, open-source JavaScript libraries.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
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.