Apache is a free and open-source cross-platform web server software.
cdnjs is a free distributed JS library delivery service.
Open Graph is a protocol that is used to integrate any web page into the social graph.
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.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
Ubuntu is a free and open-source operating system on Linux for the enterprise server, desktop, cloud, and IoT.