Apache is a free and open-source cross-platform web server software.
cdnjs is a free distributed JS library delivery service.
Debian is a Linux software which is a free open-source software.
Google Analytics is a free web analytics service that tracks and reports website traffic.
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.