AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.
ClustrMaps widget is a visitor tracker, designed for general web and blog use.
Google Tag Manager is a tag management system (TMS) that allows you to quickly and easily update measurement codes and related code fragments collectively known as tags on your website or mobile app.
Linkedin Sign-In is an authentication system that reduces the burden of login for users, by enabling them to sign in with their Linkedin account.
Open Graph is a protocol that is used to integrate any web page into the social graph.