Apache is a free and open-source cross-platform web server software.
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.
Google Analytics is a free web analytics service that tracks and reports website traffic.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.