Bootstrap is a free and open-source CSS framework directed at responsive, mobile-first front-end web development. It contains CSS and JavaScript-based design templates for typography, forms, buttons, navigation, and other interface components.
cdnjs is a free distributed JS library delivery service.
Ionicons is an open-source icon set crafted for web, iOS, Android, and desktop apps.
LiteSpeed is a high-scalability web server.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.