Apple CEO Tim Cook unveiled a new digital radio service and an operating system for the company's mobile devices that he called the biggest change ever to the iPhone.
Developers from 64 countries packed the 24th annual Worldwide Developers Conference Monday morning in San Francisco where Cook introduced the new iOS 7 to gasps in the crowd and an "I love you," shouted after the big reveal.
The new iOS7 system has a new user interface, new features, flat graphics, redesigned icons and a fresh palette of colors, all of which can be displayed on a simplified iPhone and iPad - the most radical design change since the iPhone debuted in 2007.
The operating system also has an AirDrop filesharing system and a new language for gesture interaction, meaning there will be a lot more swiping.
The system was designed by Jony Ive, who said: "We've seen iOS7 as a defining and important new direction and in many ways a beginning."
Cook added that this new operating system is the biggest change since the introduction of the iPhone. The new design will appear on iPhones, iPads and iPod Touches this fall, the company said.
The other big announcement of the day was the introduction of iTunes Radio, a Pandora-like Internet radio service that will be built into the Music app. It will run on the new operating system and be free of ads for iTunes Match subscribers.
Cook took a full hour to lead up to the big news of the day. Other updates include including new male and female voices on Siri, Apple's voice command technology, and a new look for the Mac Pro, the company's desk top model, which will launch later this year.
Cook opened the keynote at Moscone Center by talking about the status of Apple's more than 400 retail stores worldwide. He says Apple's newest store is in Berlin, at a century-old building that was one of the city's first theaters.
MORE: Apple Unveils iOS7, iTunes Radio, New MacBook Air, Mac Pro
He also touted Apple's online store, which features 900,000 apps, including 375,000 specifically designed for the iPad.
Cook later introduced a new "Mavericks" operating system - the 10th version - which Wilson Rothman of NBC News said will have "crazy power management" and will sharply reduces battery drain, according to Apple. The system will offer tabs, tagging and multiple displays. It was the first time in a decade that Apple didn't name a system after a big cat. Mavericks is a nod to the undersea rock formation that creates the great surfing in Half Moon Bay.
Cook said the upgrades to the Mac's operating system are important to the company's 5,000-plus developers so they can create and modify their apps with more ease.
Apple has also introduced a new maps app with flyover data, points of interest, which you can send to iPhone with one click.
Cook had previously said the public shouldn't expect new products until the fall. Before the conference, Cook was seen with former vice president Al Gore and the late Steve Job's wife, Laurene Powell Jobs.
The Worldwide Developers Conference runs through Friday.
MORE: Before the conference, some were speculating on what the big news of the day would be.
AP's Anick Jesdanun, NBC Bay Area's Scott Budman, NBC News William Rothman and CNBC's Jon Fortt contributed to this story.