Apache is a free and open-source cross-platform web server software.
Open Graph is a protocol that is used to integrate any web page into the social graph.
OWL Carousel is an enabled jQuery plugin that lets you create responsive carousel sliders.
Skilldo is a content management system written in PHP and paired with a MySQL or MariaDB database.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.