paypal.com

Emotion is a library designed for writing CSS styles with JavaScript.

React is an open-source JavaScript library for building user interfaces or UI components.

Svelte is a free and open-source front end compiler created by Rich Harris and maintained by the Svelte core team members.

Open Graph is a protocol that is used to integrate any web page into the social graph.

Vite is a rapid development tool for modern web projects.

Bootstrap is a free and open-source CSS framework directed at responsive, mobile-first front-end web development. It contains CSS and JavaScript-based design templates for typography, forms, buttons, navigation, and other interface components.

SvelteKit is the official Svelte framework for building web applications with a flexible filesystem-based routing.

Varnish is a reverse caching proxy.

Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.

Preact is a JavaScript library that describes itself as a fast 3kB alternative to React with the same ES6 API.

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.

Priority Hints exposes a mechanism for developers to signal a relative priority for browsers to consider when fetching resources.

HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.