Look at the URL of most pages on Facebook, and you'll see a ".php" in there somewhere. That's because Facebook has leaned heavily on the PHP scripting language to develop the Web-facing parts of the site. PHP's popularity and simplicity made it easy for the company's developers to quickly build new features. But PHP's (lack of) performance makes scaling Facebook's site to handle hundreds of billions of page views a month problematic, so Facebook has made big investments in making it leaner and faster. The latest product of those efforts is the HipHop VM (HHVM), a PHP virtual machine that significantly boosts performance of dynamic pages. And Facebook is sharing it with the world as open-source.
In 2011 I learned that emotion is at the heart of every decision we make. From fashion to web forms, and spouses to site sign ups, emotion shapes our behavior by casting the tie-breaking vote when logic determines appropriate options for our consideration. We do what feels right, we go with our gut. By understanding emotion we can gain insight into user behavior, and design better user interfaces. – Aarron Walter , User Experience Design Lead, MailChimp