cdnjs is a free distributed JS library delivery service.
Facebook pixel is an analytics tool that allows you to measure the effectiveness of your advertising.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Imgix is a visual media platform for managing, processing, rendering, optimising and delivering your existing images.
JSDelivr is a free public CDN for open-source projects. It can serve web files directly from the npm registry and GitHub repositories without any configuration.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Polyfill is a service which accepts a request for a set of browser features and returns only the polyfills that are needed by the requesting browser.
Rewardful is a way for SaaS companies to setup affiliate and referral programs with Stripe.
Stripe offers online payment processing for internet businesses as well as fraud prevention, invoicing and subscription management.