Apache is a free and open-source cross-platform web server software.
Google AdSense is a program run by Google through which website publishers serve advertisements that are targeted to the site content and audience.
Google Analytics is a free web analytics service that tracks and reports website traffic.
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.
Pinterest is an image sharing and social media service designed to enable saving and discovery of information.
Twitter is a 'microblogging' system that allows you to send and receive short posts called tweets.