HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Jimdo is a website-builder and all-in-one hosting solution, designed to enable users to build their own websites.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
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.