Amazon S3 or Amazon Simple Storage Service is a service offered by Amazon Web Services (AWS) that provides object storage through a web service interface.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Plone is a free and open source content management system (CMS) built on top of the Zope application server.
Python is an interpreted and general-purpose programming language.
Varnish is a reverse caching proxy.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.