AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.
Font Awesome is a font and icon toolkit based on CSS and Less.
Google AdSense is a program run by Google through which website publishers serve advertisements that are targeted to the site content and audience.
Modernizr is a JavaScript library that detects the features available in a user's browser.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Varnish is a reverse caching proxy.