AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.
MediaWiki is a free and open-source wiki engine.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.
Zurb Foundation is used to prototype in the browser. Allows rapid creation of websites or applications while leveraging mobile and responsive technology. The front end framework is the collection of HTML, CSS, and Javascript containing design patterns.