Express is a web application framework for Node.js, released as free and open-source software under the MIT License. It is designed for building web applications and APIs.
Google Analytics is a free web analytics service that tracks and reports website traffic.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Stripe offers online payment processing for internet businesses as well as fraud prevention, invoicing and subscription management.
Typekit is an online service which offers a subscription library of fonts.