cdnjs is a free distributed JS library delivery service.
Google PageSpeed is a family of tools designed to help websites performance optimisations.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Mailchimp is a marketing automation platform and email marketing service.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Optimizely is an experimentation platform that helps developers build and run A/B tests on websites.
Phusion Passenger is a free web server and application server with support for Ruby, Python and Node.js.
RackCache is a quick drop-in component to enable HTTP caching for Rack-based applications.