International Symposium on Software Composition

iOS

iOS (formerly iPhone OS) is a mobile operating system created and developed by Apple Inc. exclusively for its hardware. It is the operating system that presently powers many of the company's mobile devices, including the iPhone, iPad, and iPod Touch. It is the second most popular mobile operating system globally after Android.

The iOS user interface is based upon direct manipulation, using multi-touch gestures. Interface control elements consist of sliders, switches, and buttons. Interaction with the OS includes gestures such as swipe, tap, pinch, and reverse pinch, all of which have specific definitions within the context of the iOS operating system and its multi-touch interface. Internal accelerometers are used by some applications to respond to shaking the device (one common result is the undo command) or rotating it in three dimensions (one common result is switching between portrait and landscape mode). Apple has been significantly praised for incorporating thorough accessibility functions into iOS, enabling users with vision and hearing disabilities to properly use its products.

The operating system was unveiled with the iPhone at the Macworld Conference & Expo on January 9, 2007, and released in June of that year. At the time of its unveiling in January, Steve Jobs claimed: "iPhone runs OS X" and runs "desktop class applications", but at the time of the iPhone's release, the operating system was renamed "iPhone OS". Initially, third-party native applications were not supported. Jobs' reasoning was that developers could build web applications through the Safari web browser that "would behave like native apps on the iPhone". In October 2007, Apple announced that a native Software Development Kit (SDK) was under development and that they planned to put it "in developers' hands in February". On March 6, 2008, Apple held a press event, announcing the iPhone SDK.

Originally, iPod Touch users had to pay for system software updates. This was due to accounting rules making the device not a "subscription device" like iPhone or Apple TV, and significant enhancements to the device required payments. The requirement to pay to upgrade caused iPod Touch owners to stay away from updates. However, in September 2009, a change in accounting rules won tentative approval, significantly affecting both Apple's earnings and stock price, and allowing iPod Touch updates to be delivered for free.

In iPhone OS 3, Spotlight was introduced, allowing users to search media, apps, emails, contacts, messages, reminders, calendar events, and similar content. In iOS 7 and later, Spotlight is accessed by pulling down anywhere on the home screen (except for the top and bottom edges that open Notification Center and Control Center). In iOS 9, there are two ways to access Spotlight. As with iOS 7 and 8, pulling down on any homescreen will show Spotlight. However, it can also be accessed as it was in iOS 3 6. This gives a Spotlight endowed with Siri suggestions, which include app suggestions, contact suggestions and news. In iOS 10, Spotlight is at the top of the now-dedicated "Today" panel.

iOS 4 introduced folders, which can be created by dragging an application on top of another, and from then on, more items can be added to the folder using the same procedure. A title for the folder is automatically selected by the category of applications inside, but the name can also be edited by the user. When apps inside folders receive notification badges, the individual numbers of notifications are added up and the total number is displayed as a notification badge on the folder itself. Originally, folders on an iPhone could include up to 12 apps, while folders on iPad could include 20. With increasing display sizes on newer iPhone hardware, iOS 7 updated the folders with pages similar to the home screen layout, allowing for a significant expansion of folder functionality. Each page of a folder can contain up to nine apps, and there can be 15 pages in total, allowing for a total of 135 apps in a single folder. In iOS 9, Apple updated folder sizes for iPad hardware, allowing for 16 apps per page, still at 15 pages maximum, increasing the total to 240 apps.

In iOS 4.0 to iOS 6.x, double-clicking the home button activates the application switcher. A scrollable dock-like interface appears from the bottom, moving the contents of the screen up. Choosing an icon switches to an application. To the far left are icons which function as music controls, a rotation lock, and on iOS 4.2 and above, a volume controller.

In iOS 4.0 to iOS 6.x, briefly holding the icons in the application switcher makes them "jiggle" (similarly to the homescreen) and allows the user to force quit the applications by tapping the red minus circle that appears at the corner of the app's icon. Clearing applications from multitasking stayed the same from iOS 4.0 through 6.1.6, the last version of iOS 6.

Originally released as an app for iOS in February 2010, it was acquired by Apple two months later, and then integrated into iPhone 4S at its release in October 2011. At that time, the separate app was also removed from the iOS App Store.

The main hardware platform for iOS is the ARM architecture. iOS releases before iOS 7 can only be run on iOS devices with 32-bit ARM processors (ARMv6 and ARMv7-A architectures). In 2013, iOS 7 was released with full 64-bit support (which includes native 64-bit kernel, libraries, drivers as well as all built-in applications), after Apple announced that they were switching to 64-bit ARMv8-A processors with the introduction of the Apple A7 chip. 64-bit support was also enforced for all apps in the App Store; All new apps submitted to the App Store with a deadline of February 2015, and all app updates submitted to the App Store with a deadline of June 1, 2015. iOS 11 drops support for all iOS devices with 32-bit ARM processors as well as 32-bit applications, making iOS 64-bit only.

By late 2011, iOS accounted for 60% of the market share for smartphones and tablets. By the end of 2014, iOS accounted for 14.8% of the smartphone market and 27.6% of the tablet and two-in-one market. In February 2015, StatCounter reported iOS was used on 23.18% of smartphones and 66.25% of tablets worldwide, measured by internet usage instead of sales.

The closed and proprietary nature of iOS has garnered criticism, particularly by digital rights advocates such as the Electronic Frontier Foundation, computer engineer and activist Brewster Kahle, Internet-law specialist Jonathan Zittrain, and the Free Software Foundation who protested the iPad's introductory event and have targeted the iPad with their "Defective by Design" campaign. Competitor Microsoft, via a PR spokesman, criticized Apple's control over its platform.