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.
jQuery CDN is a way to include jQuery in your website without actually downloading and keeping it your website's folder.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
PagSeguro is an online or mobile payment-based ecommerce service for commercial operations.
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.
Varnish is a reverse caching proxy.