The first Apple iPhone is now 10 years old. Over that time it has become a revolutionary piece of hardware. But its gesture-based iPhone OS software -- now called iOS -- has been just as revolutionary.
Here's how Apple's groundbreaking mobile operating system has evolved from iPhone OS 1.0 to iOS 11, set to come out later this year.
For all its fanfare, the first iOS was somewhat limited. There was no App Store yet, so early adopters could only use the simple apps that came preloaded. It was basically an iPod with a phone built in.
Apple's iPhone OS 2 launched with the iPhone 3G in July 2008. The OS update brought several important new features, including always-on email push, Google Maps Street View and most importantly the App Store.
The 2011 launch of iOS 5 brought wireless updates to the iPhone, allowing it to be updated without connecting it to a computer via iTunes. The new iMessage instant messenger feature, meanwhile, allowed the sending and receipt of multimedia content over Wi-Fi.
Apple's switch from Google Maps to Apple Maps, which also occurred in iOS 6, was terribly received. The not-ready-for-primetime replacement included numerous graphics bugs and a large number of incorrect and out-of-date business listings.
Apple's iOS 7 brought a total visual refresh to the iPhone with its simple, flat-icon style.
Craig Federighi, Apple's SVP of software engineering, explained that the shadowing and texture effects used on icons in the past was a way to distract from the limitations of the display. "But with a display this precise," says Federighi, "there's nowhere to hide. So we wanted a clear typography."
The eighth major version of iOS kept the flat look of iOS 7 while adding useful new features. The iPhone got cross-platform continuity with Mac and iPad (Handoff), QuickType predictions, family sharing, Wi-Fi calling, time-lapse photos, Notification Center widgets and this handy Battery Usage feature that shows you what's draining your battery.
Apple's iOS 9 introduced a low-power mode, a Night Shift mode for easy reading after dark and mass transit support for Maps. The Notes app also got an update, seen here, that allows you to sketch with your finger.
The current iteration of iOS, version 10, introduced a sticker store for the Messages app, predictive emoji, chat bubble animations, facial recognition that bundles your photos together by person, and a Bedtime feature to help you get the perfect night's sleep.
It's only available in beta right now, but Apple has packed a ton of new features into iOS 11. Control Center can be customized, Live Photos can be edited, Siri can translate certain languages and there's a new one-handed keyboard.
Those who install iOS 11 on an iPad will also get a MacBook-like dock on the bottom of their screens.