cdnjs is a free distributed JS library delivery service.
Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services.
HTTP/3 is the third major version of the Hypertext Transfer Protocol used to exchange information on the World Wide Web.
Mailcheck is a JavaScript library designed to address the issue of misspelled email addresses during user input.
Open Graph is a protocol that is used to integrate any web page into the social graph.
PayPal is an online payments system that supports online money transfers and serves as an electronic alternative to traditional paper methods like checks and money orders.
Recurly provides enterprise-class subscription billing and recurring payment management for thousands of businesses worldwide.
Stripe offers online payment processing for internet businesses as well as fraud prevention, invoicing and subscription management.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.