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 Analytics is a free web analytics service that tracks and reports website traffic.
Open Graph is a protocol that is used to integrate any web page into the social graph.
PayPal is an online payments system that supports online money transfers and serves as an electronic alternative to traditional paper methods like checks and money orders.