Apache is a free and open-source cross-platform web server software.
cdnjs is a free distributed JS library delivery service.
Google PageSpeed is a family of tools designed to help websites performance optimisations.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
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.
PHP is a general-purpose scripting language used for web development.
Polyfill is a service which accepts a request for a set of browser features and returns only the polyfills that are needed by the requesting browser.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.