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.
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.
Google Publisher Tag (GPT) is an ad tagging library for Google Ad Manager which is used to dynamically build ad requests.