Apache is a free and open-source cross-platform web server software.
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.
OWL Carousel is an enabled jQuery plugin that lets you create responsive carousel sliders.
PHP is a general-purpose scripting language used for web development.
Popper is a positioning engine, its purpose is to calculate the position of an element to make it possible to position it near a given reference element.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.