Apache is a free and open-source cross-platform web server software.
Formidable Forms is a WordPress plugin that enables you to create quizzes, surveys, calculators, timesheets, multi-page application forms.
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.
Slider Revolution is a flexible and highly customisable slider.
WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. Features include a plugin architecture and a template system.
WPBakery is a drag and drop visual page builder plugin for WordPress.