Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services.
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.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
Sendinblue is an email marketing solution for small and medium-sized businesses that want to send and automate email marketing campaigns.