ITunes

iTunes is Apple's music and video management software. It also serves as a desktop client for the iTunes Store and handles iOS device synchronization.

It consists of two major components: iTunes itself, and Apple Mobile Device Support (AMDS). Apple Mobile Device Support is the component responsible for synchronizing with iOS devices. Previous versions included QuickTime, which was used for media playback.

From version 9 to 12.10.8.5, iTunes on Windows includes a component called Apple Application Support, which includes WebKit and some other Apple libraries and tools. It is used to display the iTunes Store, as well as iTunes LPs and iTunes Extras.

iTunes has a long legacy as the "hub" for Apple's portable devices, and has often been criticized for its complexity as a result of its need to support many use cases. Apple has responded to this criticism by rearchitecting iTunes and other software to reduce such complexity:


 * On 2011, iOS 5 removed its dependence on iTunes for initial activation, now being possible directly on the device itself. The introduction of iCloud simultaneously with iOS 5 introduced an alternative mechanism for backing up a device. iTunes can still optionally be used for activation in conditions where the device doesn't have access to the internet, but a computer does. It can also be used in place of iCloud for more complete, local backups. Additionally, the iTunes 10.2 release removed its dependency on QuickTime.
 * On 2017, iTunes 12.7 removed support for browsing, downloading, and synchronizing apps from the App Store, and ringtones from the iTunes Store. It additionally discontinued support for synchronization or streaming content to Apple TV (1st generation). Due to the major feature removals, the iTunes 12.6 branch continued to receive updates, starting with 12.6.3.6 on 2017, and ending with 12.6.5.3 on 2018.
 * On 2019, macOS Catalina replaced iTunes with the Music and TV apps (as a continuation of the iTunes codebase), Podcasts (as a Catalyst port of the iOS Podcasts app), and iOS/iPod device sync functionality in Finder.
 * On 2023, Apple released previews of Music and TV apps for Windows, in addition to a new Apple Devices app, replicating the device management functionality that was merged into Finder.

iTunes still receives updates on Windows, however, it is expected to be retired when the Music, TV, and Devices apps exit their preview state.

iTunes 1.x
iTunes 1.0 was released for Mac OS 9 on 2001, having been derived from the SoundJam MP codebase Apple had acquired from Casady & Greene. iTunes was first released for Mac OS X on 2001 with version 1.1, and it became a built-in app with the release of Mac OS X 10.1.

Mac OS 9
Initial versions of iTunes supported Mac OS 9.0.4 and later. Mac OS 9.1 is required to burn CDs. Apple says "iTunes works with all Macintosh Computers that have built-in USB ports".

macOS
Mac OS X support was introduced with iTunes 1.1.

iTunes 2.x
Alongside the launch of the iPod on 2001, iTunes 2.0 was released to provide its syncing functionality.

iTunes 2 is the final series to support Mac OS 9.

iTunes 4.x


The iTunes Store was launched on 2003 with the release of iTunes 4.0. Notably, iTunes 4.0 was the first version to support the AAC audio codec, used by all music purchases from the iTunes Store.

On 2003, iTunes 4.1 was released, supporting Windows for the first time - obsoleting Apple's reliance on an iPod plugin for MusicMatch Jukebox to provide iPod syncing functionality to Windows users. The launch of iTunes 4.1 coincided with the iPod+HP partnership.

On 2004, iTunes 4.5 added support for the Apple Lossless (ALAC) audio codec.

On 2004, iTunes 4.6 added support for AirPlay, then known as AirTunes.

iTunes 4 tweaks the app icon to use a green music note.

iTunes 5.x
iTunes 5 retains the icon of its predecessor. Only two versions were released in this branch.

iTunes 6.x
On 2006, iTunes 6.0.2 added native support for Intel Macs.

On 2006, iTunes 6.0.5 added support for Nike+iPod.

iTunes 6 retains the icon of its predecessor.

iTunes 7.x


On 2006, iTunes 7.0 introduced the three-dimensional Cover Flow album browser feature. Cover Flow, and the redesigned "source list" sidebar, were later integrated into Finder with Mac OS X Leopard.

On 2007, iTunes 7.1 added support for the Apple TV (1st generation).

Coinciding with the launch of the iPhone on 2007, iTunes 7.3 was released with support for activating the device, and syncing a music library to it. A Mac, or a Windows computer running Windows XP or Vista, was required to activate and sync an iPhone. A separate release of iTunes for Windows 2000 was released simultaneously, lacking support for the iPhone.

On 2007, iTunes 7.4 added support for the newly-launched iPods, including the iPod touch, iPod classic (6th generation), and iPod nano (3rd generation).

Coinciding with the launch of the iPhone 3G, iPhone OS 2.0, and the App Store on 2008, iTunes 7.7 was released with support for the new device, and for downloading and syncing .ipa-packaged apps from within the iTunes Store section of the app. The Remote app was also released.

iTunes 7 tweaks the icon of its predecessor, changing the color of the music note to blue. The center of the disc has an inscription: "iTunes 7 - […]20806 - Apple 2006".

64-bit
With iTunes 7.6, Apple introduced a 64-bit edition of iTunes.

Windows 2000
For a brief period, Apple released separate iTunes downloads for users of Windows 2000, before discontinuing support for Windows 2000 entirely. These releases lack Apple Mobile Device Support, meaning iOS devices are not supported.

iTunes 8.x
iTunes 8 retains the icon of its predecessor, despite the "iTunes 7" inscription in the center of the disc.

iTunes 9.x


Coinciding with the launch of the iPad and iBooks on 2010, iTunes 9.1 was released with support for the device, including downloading and syncing books from the iBooks Store.

iTunes 9 retains the icon of its predecessor, however, it removes the text in the center of the disc.

iTunes 10.x


Coinciding with the launch of the Apple TV (2nd generation) on 2010, the first Apple TV to run a variant of iOS, iTunes 10.0 was released with support for the device, additionally introducing the iTunes Ping social network.

Coinciding with the launch of iCloud and iOS 5 on 2011, iTunes 10.5 was released with support for Wi-Fi Sync and iTunes in the Cloud. Notably, QuickTime was no longer bundled with the iTunes installer on Windows; its functionality now handled internally by iTunes.

On 2011, iTunes 10.5.1 added support for iTunes Match.

iTunes 10 brought the most significant icon change, eliminating the disc entirely to signify the app's broadened focus to all media. The icon was designed by Louie Mantia.

Windows
With the release of iTunes 10.5, QuickTime components were integrated into iTunes itself, and as such iTunes Setup no longer installs QuickTime.

iTunes 11.x


iTunes 11 brought a significant redesign of the app, with a focus on navigation through the top toolbar, rather than the source list sidebar that has been used since iTunes 7.

On 2013, iTunes 11.1 added support for iTunes Radio.

iTunes 11 tweaks the icon of its predecessor, bringing a softer background color, and a white music note rather than black.

iTunes 12.x


iTunes 12 is the longest-running release of the app, initially releasing on 2014. Many features have been removed over time, being replaced with independent apps under the Apple Media Services umbrella that replaces the iTunes brand.

Coinciding with the launch of Apple Music on 2015, iTunes 12.2 was released with support for the service.

On 2017, iTunes 12.7 removed support for browsing, downloading, and synchronizing apps from the App Store, including the "Applications" tab that provided a desktop view of the device's home screen. It additionally removed support for ringtones, and entirely discontinued support for synchronization or streaming content to Apple TV (1st generation). Due to the major feature removals, the iTunes 12.6 branch continued to receive updates, starting with 12.6.3.6 on 2017, and ending with 12.6.5.3 on 2018.

On 2018, iTunes 12.8 added support for AirPlay 2.

On 2018, with the release of iTunes 12.9, Apple's release strategy for iTunes on macOS changed to no longer treat it as a separately upgradable component. This and all future versions were exclusively bundled with macOS Mojave, and cannot be downloaded as a .dmg nor installed on prior versions of macOS, as had been possible up to this point. A year later, in macOS Catalina, iTunes was replaced by the Music and TV apps (as a continuation of the iTunes codebase), Podcasts (as a Catalyst port of the iOS Podcasts app), and iOS/iPod device sync functionality in Finder.

iTunes 12 again brought with it a tweak to the icon style introduced in iTunes 10, switching to a red-orange gradient matching the redesigned Music app icon introduced with iOS 7. iTunes 12.2, alongside iOS 8.4's Music app, again tweaked the icon, inverting the scheme to a crimson red, violet, and sky blue music note on a white circle background.

Older video cards
With iTunes 12.1, Apple bundled 64-bit versions of Apple Mobile Device Support and Apple Application Support with iTunes. For iTunes 12.1 through 12.4.3.1, Apple also offered a version for 64-bit Windows computers with older video cards, which keep the 32-bit versions of said libraries. Installing this version is necessary when using a 32-bit program expecting 32-bit libraries, such as many older jailbreak/jailbreak-related tools.

With iTunes 12.6, the change was reverted such that the 64-bit release of iTunes includes 32-bit libraries again. No "older video cards" release was made for iTunes 12.5.

Deprecation of iTunes
As of macOS Catalina, iTunes has been replaced by separate Music, Podcasts, TV, and Books apps, with iOS device functionality merged into Finder. iTunes 12.9.5.5 is the final release on macOS, bundled with macOS Mojave 10.14.6 Supplemental Update (Build 18G95).

Additionally, since at least macOS High Sierra (possibly as early as the introduction of System Integrity Protection in OS X El Capitan), Apple Mobile Device Support handles its own updates. When a device unknown to the currently installed build of AMDS is connected, MobileDeviceUpdater.app prompts the user to install a software update. Previously, AMDS would only be updated by installing a full iTunes or Xcode update.

iTunes is still in use on Windows, however it is soon to be replaced by the Apple Music, Apple TV, and Apple Devices apps, currently in preview.