Facebook CEO <a gi-track='captionPersonalityLinkClicked' href=/galleries/search?phrase=Mark+Zuckerberg&family=editorial&specificpeople=4841191 ng-click='$event.stopPropagation()'>Mark Zuckerberg</a> delivers the opening keynote at the Facebook f8 conference on April 30, 2014 in San Francisco, California. Facebook is hosting the one-day developers conference for the first time since 2011 and over 1500 developers are expected to attend.