Braintree, a division of PayPal, specializes in mobile and web payment systems for ecommerce companies. Braintree provides clients with a merchant account and a payment gateway.
cdnjs is a free distributed JS library delivery service.
Firebase is a Google-backed application development software that enables developers to develop iOS, Android and Web apps.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
HTTP/3 is the third major version of the Hypertext Transfer Protocol used to exchange information on the World Wide Web.