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.
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.
Phusion Passenger is a free web server and application server with support for Ruby, Python and Node.js.
Pinterest is an image sharing and social media service designed to enable saving and discovery of information.