HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Mapbox GL JS is a JavaScript library that uses WebGL to render interactive maps from vector tiles and Mapbox styles.
Mapbox.js is a JavaScript library provided by Mapbox for working with interactive maps and geospatial data.
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.