Apple's Biggest Breakthrough That Almost No One Knows About

Ask the average Apple fan to make a list of the important moves the company has made in the past year or so, and the list will probably start with the Apple Watch before ticking off the huge sales of bigger iPhones and the $3 billion deal for Beats Electronics. A particularly news-savvy fan might even cite rumors about an Apple car. Put the same question to an Apple developer, and the list of milestones will almost certainly include something that has flown under the radar of most devoted Apple users: Swift, a new computer language introduced by the company a year ago.

Developers gasped and applauded as Craig Federighi, Apple’s senior vice president for software engineering, first ran through such features as type inference, closures, and multiple name spaces. “You know how many people are home are going, ‘What in the heck are these guys talking about?” Federighi joked when he unveiled Swift at last year's Worldwide Development Conference. People who didn’t care about, say, the speed of RC4 encryption quickly forgot all about those few minutes of confusion. Programmers didn't. Many of those attending this year's WWDC, which starts on June 8, have spent the past year learning how to write apps using Swift.