 | |
|---|---|
 iOS 4.2.1 home screen on an iPhone | |
| Company / developer | Apple Inc. |
| Programmed in | C, C++, Objective-C |
| OS family | Mac OS X/BSD |
| Working state | Current |
| Initial release | June 29, 2007 |
| Latest stable release | 4.2.1 (Build 8C148, except iPhone 3GS 8C148a) For iPad, iPhone & iPod touch (November 22, 2010) 4.2.5 (8E128) (Verizon iPhone Only) (January 11, 2011) [+/−] |
| Latest unstable release | 4.3 Beta 2 (Build 8F5148d) For iPhone 4, iPhone 3GS, iPad, iPod Touch 3rd and 4th Gen & Apple TV Released January 19, 2011 [+/−] |
| Available language(s) | Multilingual |
| Supported platforms | ARM (iPhone, iPod Touch, iPad, and 2nd gen Apple TV) |
| Kernel type | Hybrid (Darwin) |
| Default user interface | Cocoa Touch (Multi-touch, GUI) |
| License | Proprietary EULA except for open source components |
| Official website | apple.com/ios |
The user interface of iOS is based on the concept of direct manipulation, using multi-touch gestures. Interface control elements consist of sliders, switches, and buttons. The response to user input is immediate and provides a fluid interface. Interaction with the OS includes gestures such as swiping, tapping, pinching, and reverse pinching. 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 from portrait to landscape mode).
iOS is derived from Mac OS X, with which it shares the Darwin foundation, and is therefore a Unix-like operating system by nature.
In iOS, there are four abstraction layers: the Core OS layer, the Core Services layer, the Media layer, and the Cocoa Touch layer. The operating system uses roughly 500 megabytes of the device's storage, varying for each model.[4]
History
The operating system was unveiled with the iPhone at the Macworld Conference & Expo on January 9, 2007, and released in June of that year.[5] At first, Apple marketing literature did not specify a separate name for the operating system, stating simply that the "iPhone runs OS X".[6] Initially, third-party applications were not supported. Steve Jobs argued that developers could build web applications that "would behave like native apps on the iPhone".[7][8] On October 17, 2007, Apple announced that a native SDK was under development and that they planned to put it "in developers' hands in February".[9] On March 6, 2008, Apple released the first beta, along with a new name for the operating system: iPhone OS.Brisk sales of Apple mobile devices kindled interest in the SDK.[citation needed] The previous September, Apple had released the iPod touch, which had most of the non-phone capabilities of the iPhone. Apple also sold more than one million iPhones during the 2007 holiday season.[10] On January 27, 2010, Apple announced the iPad, featuring a larger screen than the iPhone and iPod Touch, and designed for web browsing, media consumption, and reading iBooks.[11]
In June 2010, Apple rebranded iPhone OS as iOS. The name IOS had been used by Cisco for over a decade for its IOS used on Cisco routers. To avoid any potential lawsuit, Apple licensed the "IOS" trademark from Cisco.[12]
Version history
Main article: iOS version history
Version 4, announced in April 2010, introduced multitasking, threaded email, and several business-oriented features.[13] At the WWDC 2010 keynote on June 7, 2010, Apple announced that iPhone OS had been renamed iOS.[14] Apple licensed the trademark for "iOS" from Cisco Systems (which owns IOS), the same company with which Apple had earlier settled a dispute over the "iPhone" trademark.[15]Apple released iOS 4 on June 21, 2010, three days before the iPhone 4,[16] in an effort to reduce the strain on Apple's servers. iOS 4 is the first version of the OS to be a free upgrade on the iPod Touch; Apple had charged $9.99 for earlier upgrades. Apple previously announced that iPad users with 3.x software would receive a free upgrade to the next major (4.x) release.[17]
iOS 4.0.1 includes a fix to the reception signal strength indicator. It was released on July 15, 2010, the day before Apple hosted a press conference to discuss its response to the widely publicized iPhone antenna issues. Apple also released iOS 3.2.1 for the iPad which tweaks the tablet's Wi-Fi connectivity, video playback, and copy-and-paste for PDF attachments, among other updates.
iOS 4.0.2 for iPhone and iPod Touch and iOS 3.2.2 for the iPad were released on August 11, 2010, to fix a pair of security vulnerabilities.[18]
iOS 4.1 for the iPhone and iPod Touch was released on September 8, 2010; the update fixes some bugs reported by users, improves battery life and adds a new feature called Game Center, which allow gamers to multiplay, upload high scores and to unlock achievements (though, Apple removed Game Center from the iPhone 3G due to reports on slow performance) and adds initial support for the iPod Touch 4th Generation and the Apple TV 2G. iOS 4.1 also updated carrier settings which in the US was AT&T 8.0 and enabled toggling Check Spelling On/Off. iOS 4.1 also adds HDR photography,[19] a feature that only the iPhone 4 is capable of using. TV Show Rentals are available on the iTunes US Store. iOS 4.1 also adds a new feature called Ping which is a social music network and discovery tool.
iOS 4.2 was released to developers on November 8, 2010. It was never released to the public as a Wi-Fi bug was found during the limited release. Apple then issued two more golden master releases. Finally, Apple released iOS 4.2.1 to the public.
iOS 4.2.1 was released on November 22, 2010 with support for all Apple A4 devices, 3rd-, and 2nd-generation devices, with the exclusion of the Apple TV. It brings initial support of iOS 4.x to iPad, plus AirPlay and AirPrint to all compatible devices. It also contains minor changes to the YouTube app and alters the multitasking animation. On iPad, the screen rotation lock button's functionality changes to mute, the same as it was originally planned. As a known major bug, this version seems to hinder the usage of the Camera Connection Kit on the iPad.
iOS 4.2.5 was released as a demo version for the CDMA version of the iPhone 4. This iPhone 4 variant will be available to current Verizon Wireless customers in the US on February 10, 2011, but pre-ordering will be available for qualified Verizon Wireless Customers on February 3. This version has some slight UI changes specifically for the CDMA version of the phone, including a "Personal Hotspot" switch in the Settings app, a service which has to be activated by the carrier in order for the feature to be usable. This will be able to be purchased from Verizon as a separate plan, as is currently possible on other smartphones.
iOS 4.3 beta was released to developers on January 12, 2011.
Features
Home screen
The home screen (rendered by "SpringBoard") with application icons, and a dock at the bottom of the screen where users can pin their most frequently used apps, is presented whenever the device is turned on or the home button pressed. The screen has a status bar across the top to display data, such as time, battery level, and signal strength. The rest of the screen is devoted to the current application.[edit] Folders
With iOS 4 came the introduction of a simple foldering system. When applications are in "wiggle mode," any two can be dragged on top of each other to create a folder, and from then on, any other 10 "apps" can be added to the folder using the same procedure (maximum folders can handle is 12 on iPhone and iPod Touch and 20 on iPad.) A title for the folder is automatically selected by the type of applications inside, but the name can also be edited by the user.Included applications
The iPhone home screen contains these default "apps". Some of these applications are hidden by default and accessed by the user through the Settings app or another method. (For instance, Nike+iPod is activated through the Settings app, and the AirPrint activates when a user prints a file)Name | Usage | Version Included |
|---|---|---|
| Phone | Telephone, FaceTime video calling | 1.0+ (FaceTime video calling 4.0+) |
| E-mail client | 1.0+ | |
| Safari | Web browser | |
| iPod | Portable media player |
| Name | Usage | Version Included |
|---|---|---|
| Messages | Text messaging, MMS | 1.0+ (MMS 3.0+) |
| Calendar | Calendar | 1.0+ |
| Photos | Photo viewer | 1.0+ (Video viewer 2.0+) |
| Camera | Camera, Camcorder | 1.0+ (Video recording and auto-focus iPhone 3GS (3.0) onwards, HD video iPhone 4 (4.0) and iPod Touch 4 (4.1) onwards, HDR iPhone 4 (4.1) onwards) |
| YouTube | YouTube video streamer | 1.0+ |
| FaceTime | Video calling | 4.0 (For iPhone 4) & 4.1+ (4th Gen iPod touch Only, FaceTime can be accessed through the Phone app on the iPhone 4) |
| Stocks | Yahoo! Finance | 1.0+ |
| Maps | Google Maps | 1.0+ (Assisted GPS 2.0+, Compass 3.0+ (iPhone 3GS onwards)) |
| Weather | Yahoo! Weather | 1.0+ |
| Voice Memos | Voice recorder | 3.0+ |
| Notes | A simple note-taking program | 1.0+ |
| Clock | World clock, stopwatch, alarm clock and timer | |
| Calculator | Calculator (includes scientific version) | 1.0+ (Scientific calculator 2.0+) |
| Settings | Settings | 1.0+ |
| iTunes | To access the iTunes Music Store and iTunes Podcast Directory | 1.1+ |
| App Store | To buy iOS apps | 2.0+ |
| Compass | Compass | 3.0+ (iPhone 3GS onwards) |
| Contacts | Address/phone book | 1.0+ (Separate application for iPhone 2.0 onwards) |
| Nike + iPod | Records the distance and pace of a walk or run; can connect to Nike + iPod sensor | 2.2.1+ (iPod Touch, 2nd Generation onwards), 3.0+ (iPhone 3GS onwards) |
| Game Center | Allows the user to play multiplayer games with other users, track in game achievements and view leaderboards. | 4.1+ (iPod Touch, 2nd Generation onwards, iPhone 3GS onwards) |
| Personal Hotspot | Allows the user to tether the iPhone's 3G Data for up to 5 devices via Wi-Fi | 4.2.5 & 4.3 (iPhone 4 only) |
The iPod Touch retains the same applications that are present by default on the iPhone, with the exception of the Phone, Messages, Compass and Camera apps. The "iPod" App present on the iPhone is split into two apps on the iPod Touch: Music, and Videos. The bottom row of applications is also used to delineate the iPod Touch's main purposes: Music, Videos, Safari, and App Store (Dock Layout was changed in 3.1 Update). For the 4th Generation iPod Touch, it includes FaceTime and Camera, and the dock layout had changed to Music, Mail, Safari, Video.
The iPad comes with the same applications as the iPod Touch excluding Stocks, Weather, Clock, Calculator, and the Nike + iPod app. Separate music and video apps are provided, as on the iPod Touch, although (as on the iPhone) the music app is named "iPod". Most of the default applications are completely rewritten to take advantage of the iPad's larger display. The default dock layout includes Safari, Mail, Photos and iPod.
Multitasking
Before iOS 4, multitasking was limited to a selection of the applications Apple included on the devices.[22] Apple worried that running multiple third-party applications simultaneously would drain batteries too quickly. Starting with iOS 4, on 3rd-generation and newer iOS devices, multitasking is supported through seven background APIs:[23]- Background audio
- Voice over IP
- Background location
- Push notifications
- Local notifications
- Task finishing
- Fast app switching
Switching applications
Double-pressing 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, and a rotation lock. Holding the icons briefly makes them wiggle (similarly to the homescreen) and allows the user to quit the applications.Game Center
Main article: Game Center
Game Center is an online multiplayer "social gaming network"[24] released by Apple.[25] It allows users to "invite friends to play a game, start a multiplayer game through matchmaking, track their achievements, and compare their high scores on a leader board."[24]Game Center was announced during an iOS 4 preview event hosted by Apple on April 8, 2010. A preview was released to registered Apple developers in August.[24] It was released on September 8, 2010 with iOS 4.1 on iPhone 4, iPhone 3GS and iPod Touch 2nd generation through 4th generation. Game Center made its public debut on the iPad with iOS 4.2.1.[26] There will be no support for the iPhone 3G and original iPhone. However, Game Center is unofficially available on the iPhone 3G via a hack.[27]
Development
The applications must be written and compiled specifically for iOS and the ARM architecture. The Safari web browser supports web applications as with other web browsers. Authorized third-party native applications are available for devices running iOS 2.0 and later through Apple's App Store.SDK
Developers are able to set any price above a set minimum for their applications to be distributed through the App Store, of which they will receive a 70% share. Alternately, they may opt to release the application for free and need not pay any costs to release or distribute the application except for the membership fee.[30]
Jailbreaking
iOS has been subject to a variety of different hacks centered on adding functionality not supported by Apple. Before the 2008 debut of the App Store, the primary reason for jailbreaking was to install third-party native applications.[31] Apple said it would not design software updates specifically to break these native apps (other than applications that perform SIM unlocking), however with each iOS update the jailbreak appears to no longer work.[32]Since the arrival of the App Store and third-party applications, the focus of the jailbreaking community has shifted.[33] A major focus of jailbreaking is allowing theming, using emulators and community-made tweaks like multitasking, Adobe Flash player, accessing the iPhone file system, downloading cracked apps from the appstore using Install0us and customizing the SpringBoard further. Multitasking is only supported on 3rd-generation and newer iOS devices, and applications on the App Store are not allowed to modify the look of the OS.
Some jailbreakers also attempt to illegally share paid App Store applications. This focus has caused some strife within the jailbreaking community, as it was not the original focus of jailbreaking and is illegal.[34]
Digital rights management
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.[35][36][37][38] Competitor Microsoft, via a PR spokesman, has also criticized Apple's control over its platform.[39]At issue are restrictions imposed by the design of iOS, namely DRM intended to lock purchased media to Apple's platform, the development model (requiring a yearly subscription to distribute apps developed for the iOS), the centralized approval process for apps, as well as Apple's general control and lockdown of the platform itself. Particularly at issue is the ability for Apple to remotely disable or delete apps at will.
Some in the tech community have expressed concern that the locked-down iOS represents a growing trend in Apple's approach to computing, particularly Apple's shift away from machines that hobbyists can "tinker with" and note the potential for such restrictions to stifle software innovation.[40]
However, there are some outside of Apple who have voiced support for the iOS closed model. Facebook developer Joe Hewitt, who had previously protested against Apple's control over its hardware as a "horrible precedent", has subsequently argued the locked apps in the iPad are akin to web applications and provide added security.
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