iOS is the operating system that runs Apple’s iPhone, and later the iPod touch and iPad. It launched with the original iPhone in 2007 under the name iPhone OS, a touch-oriented relative of the Mac’s OS X, and was renamed iOS in 2010 once it ran on more than just phones. For its first year it was a closed system: Apple shipped the built-in apps, and outside developers were limited to web applications running in the Safari browser.
The decisive moment for iOS as a developer platform came on March 6, 2008, when Apple previewed its iPhone 2.0 software and released the iPhone SDK. Apple’s press release announced “the immediate availability of a beta release of the software to selected developers and enterprise customers,” and described “a rich set of Application Programming Interfaces (APIs)” that let developers build native applications for iPhone and iPod touch. The same announcement introduced the iPhone Developer Program and previewed the App Store as the channel through which those apps would reach users.
Developer interest was immediate. Within days Apple reported that “more than 100,000 iPhone developers downloaded the beta iPhone Software Development Kit (SDK) in the first four days since its launch on March 6.” The SDK established the toolchain that still defines Apple app development: apps were written against frameworks such as UIKit, built in the Xcode integrated development environment on a Mac, and tested in a software Simulator before being run on a device.
The economic terms set in 2008 also proved durable. Developers paid a 99-dollar annual fee to join the program, and Apple’s model gave developers 70 percent of paid-app revenue while Apple retained 30 percent. That 70/30 split, paired with mandatory App Store distribution and review, became the template not only for iOS but for app marketplaces across the industry.
Originally written in Objective-C, iOS development gained a second official language in 2014 with the introduction of Swift. Across both languages the platform kept the shape laid down in 2008 - a curated operating system, a Mac-based SDK and toolchain, and a single official store - making iOS one of the most influential software platforms of the smartphone era.