Apple’s annual developer conference saw chief executive Tim Cook and head of software engineering Craig Federighi dominate the stage. Apple showed off new operating systems, including iOS8 and the newly-minted OS X Yosemite, as well as HealthKit, its first foray into fitness tracking, and HomeKit, a connected home platform. Not to mention tools for developers and a new programming language called Swift. Tim Bradshaw, Richard Waters and Sarah Mishkin give the rundown and reaction from the Moscone Center in San Francisco.