AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.
Apache is a free and open-source cross-platform web server software.
cdnjs is a free distributed JS library delivery service.
DoubleClick Ad Exchange is a real-time marketplace to buy and sell display advertising space.
Google AdSense is a program run by Google through which website publishers serve advertisements that are targeted to the site content and audience.
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.
PHP is a general-purpose scripting language used for web development.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.