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.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Optimizely is an experimentation platform that helps developers build and run A/B tests on websites.
Stripe offers online payment processing for internet businesses as well as fraud prevention, invoicing and subscription management.
Sumo is a plugin offering set of marketing tools to automate a website's growth. These tools help drive extra traffic, engage visitors, increase email subscribers and build community.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.