Fastly is a cloud computing services provider. Fastly's cloud platform provides a content delivery network, Internet security services, load balancing, and video & streaming services.
GitHub Pages is a static site hosting service.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
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.
Pure CSS is a set of small, responsive CSS modules that can be used in web projects.
Unpkg is a content delivery network for everything on npm.
Varnish is a reverse caching proxy.