AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.
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.
Apache is a free and open-source cross-platform web server software.
cdnjs is a free distributed JS library delivery service.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Twitter is a 'microblogging' system that allows you to send and receive short posts called tweets.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.