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.
Google Sign-In is a secure authentication system that reduces the burden of login for users, by enabling them to sign in with their Google account.
Ionicons is an open-source icon set crafted for web, iOS, Android, and desktop apps.
Moment.js is a free and open-source JavaScript library that removes the need to use the native JavaScript Date object directly.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
PHP is a general-purpose scripting language used for web development.
VK is a Russian online social media and social networking service.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.