JSDelivr is a free public CDN for open-source projects. It can serve web files directly from the npm registry and GitHub repositories without any configuration.
LiteSpeed is a high-scalability web server.
Popper is a positioning engine, its purpose is to calculate the position of an element to make it possible to position it near a given reference element.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.