AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.
Disqus is a worldwide blog comment hosting service for web sites and online communities that use a networked platform.
Google AdSense is a program run by Google through which website publishers serve advertisements that are targeted to the site content and audience.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.