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.
JSDelivr is a free public CDN for open-source projects. It can serve web files directly from the npm registry and GitHub repositories without any configuration.
Mailchimp is a marketing automation platform and email marketing service.
MathJax is a cross-browser JavaScript library that displays mathematical notation in web browsers, using MathML, LaTeX and ASCIIMathML markup.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Ubuntu is a free and open-source operating system on Linux for the enterprise server, desktop, cloud, and IoT.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.