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 Tag Manager is a tag management system (TMS) that allows you to quickly and easily update measurement codes and related code fragments collectively known as tags on your website or mobile app.
Kakao platform provides various services such as Kakao Talk, Kakao Talk Channel, Kakao Story as well as Kakao Pay, Kakao Commerce, Kakao Page provided by the subsidiaries. Users can use all Kakao platform services with a united account called Kakao Account.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
SweetAlert2 is a JavaScript library that provides customisable, visually appealing, and responsive alert and modal dialog boxes for web applications.
Ubuntu is a free and open-source operating system on Linux for the enterprise server, desktop, cloud, and IoT.
Unpkg is a content delivery network for everything on npm.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.