Apache is a free and open-source cross-platform web server software.
CentOS is a Linux distribution that provides a free, community-supported computing platform functionally compatible with its upstream source, Red Hat Enterprise Linux (RHEL).
Facebook pixel is an analytics tool that allows you to measure the effectiveness of your advertising.
Google Analytics is a free web analytics service that tracks and reports website traffic.
Mailchimp is a marketing automation platform and email marketing service.
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.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.