The version history of iTunes begins in 1998 and continues to the present day. Initially conceived as a simple music player, over time iTunes developed into a sophisticated multimedia content manager, hardware synchronization manager and e-commerce platform. The current version of iTunes enables users to manage media content, create playlists, synchronize media content with handheld devices including the iPod, iPhone and iPad, re-image and update handheld devices, stream Internet radio and purchase music, films, television shows, audiobooks and applications via the iTunes Store.
Apple based the initial release of iTunes on SoundJam MP, a program developed by Bill Kincaid and released by Casady & Greene in 1999. Apple purchased the program from Casady & Greene in 2000. At the time of the purchase, Kincaid, Jeff Robbin and Dave Heller left Casady & Greene to continue development of the program as Apple employees. At Apple, the developers simplified SoundJam's user interface, added the ability to burn CDs, and removed the program's recording feature and skin support.
Apple released version 1.0 of the program under a new name, "iTunes", on January 9, 2001, at Macworld San Francisco. Macintosh users immediately began poking through iTunes's resource fork, where they discovered numerous strings and other resources that indicated that iTunes was a re-engineered Sound Jam MP. Casady & Greene ceased distribution of SoundJam MP on June 1, 2001 at the request of the developers.
Originally a Mac OS 9-only application, iTunes began to support Mac OS X with the release of version 2.0 in October, 2001. Release 2.0 also added support for a then-new product, the iPod. Version 3 dropped Mac OS 9 support but added smart playlists and a ratings system. In April 2003, version 4.0 introduced the iTunes Store; in October, version 4.1 added support for MicrosoftWindows 2000 and Windows XP. Introduced at Macworld 2005 with the new iPod Shuffle, Version 4.7.1 introduced the ability to convert higher-bitrate songs to 128kbit/s AAC automatically, as these devices did not natively support audio encoded in AIFF or Apple Lossless formats, also improving the value proposition of the Shuffle's limited flash-only storage. Version 7.0 introduced gapless playback and Cover Flow in September 2006. In March 2007, iTunes 7.1 added support for Windows Vista, and 7.3.2 was the last Windows 2000 version.
iTunes lacked support for 64-bit versions of Windows until the 7.6 update on January 16, 2008. iTunes is currently supported under any 64-bit version of Windows, although the iTunes executable is still 32-bit. The 64-bit versions of Windows XP and Windows Server 2003 are not supported by Apple, but a workaround has been devised for both operating systems. Version 8.0 added Genius playlists, grid view, and a new default visualizer.
On September 1, 2010, Apple held their annual music press event where they unveiled an updated version: iTunes 10. The new version was available for download later that day. One major feature includes the integration of "iTunes Ping", which brings a social factor to the iTunes experience. Apple CEO Steve Jobs also announced a new logo, one without a CD in the background because of the increasing popularity of iTunes digital downloads.
In October 2012, Apple announced the launch of the iPhone 5 and iPad Mini, the refresh of the iPod and Mac lines, and the upcoming release of iTunes 11. Slated for release by the end of October, the launch was pushed back to November 29, 2012. This version included tighter integration with iCloud, and a new user interface. Users' libraries now include all media they have stored in their iCloud account, along with any media unique to the device they are using. Media stored in the cloud don't need to be downloaded before playing, allowing a larger collection to be accessible without increased disk usage. The new user interface includes a refreshed grid view, which replaces Cover Flow as the default layout method. With this change, Cover Flow is no longer available within the application. With the release of this software, the iTunes Store was redesigned to remain consistent with the new interface, and the stores available on iOS devices. The social element Ping was also removed and replaced by increased Twitter and Facebook integration. Other minor changes included disabling the sidebar by default, and slightly altering the icon to match that of the Mac App Store better.
Fully supports Vista, iTunes Plus introduced with 256 kbit/s DRM-free music tracks,iTunes U introduced which offers free content from some of the top universities around the United States. Also included GUI Update for Windows Vista
Allows activation of iPhones outside of the United States wherever activation is available, (e.g. United Kingdom and Germany) as well as security and stability fixes. Also included is a GUI update for Leopard, and the ability to add custom ringtones for free. Includes support for iPod game Phase. Shows iPod battery level in source list (iPod Nano 3G, iPod Classic, iPod Touch, and iPhone with 1.1.2 software).
Genius Sidebar and playlists, Grid View, HD TV shows, Shows capacity of Apps on iPhone/iPod Touch on device summary tab, new default visualizer, more flexible podcast options and support for second generation iPod Touch and 4th generation iPod Nano.
Addresses a quality issue creating MP3s on some computers. Fixes a connectivity issue with the iTunes Store when using some Internet proxies with Mac OS X. Improves accessibility with VoiceOver. Support for iOS 2.2.
Support for the third generation iPod Shuffle, speed improvements for browsing large libraries and the iTunes Store, as well as 'preparing to sync' and 'optimizing photos' for syncing to iPods and iPhones, Party Shuffle has been replaced by iTunes DJ which now has the ability to receive requests for songs, the ability to import/convert files and CDs to iTunes Plus format, better performance when downloading iTunes Plus songs, accessibility improvements, Genius has been expanded to cover TV shows and movies, refined parental controls and refined auto-fill options. Supports Multi-touch gestures.
Provides a number of important bug fixes and addresses an issue with verification of Apple devices. The latter refers to the disabling of iTunes' ability to sync with the Palm Pre; the Pre has a feature called "MediaSync" which allowed version 8.2 to register and sync songs and videos between iTunes and the Pre. This functionality has since been restored with the latest version of webOS. Bundled with Mac OS X v10.6. This is the last version that fully supports Macs with a G3 processor.
New UI and redevelopment of the iTunes Store using WebKit. Genius Mixes were added, as were Home Sharing, iTunes LPs and iTunes Extras. Support for activation/syncing of iPod touch (late 2009). Music is automatically added to the library from a watched folder. The shopping cart in the Store has been removed, now only 1-Click purchases can be made. Some compatibility issues with the iPod Classic.
No longer ignores "Remember password for purchases" setting, addresses problems with syncing smart playlists and podcasts with iPod, resolves problem recognizing when iPod is connected, and addresses issues that affect stability and performance.
Adds support for iPad, adds the ability to sync and organize downloaded books between iPad and the iTunes library, and Genius Mixes can now be renamed, rearranged, or removed. "Applications" are renamed "Apps".
Addresses several stability issues with VoiceOver, a usability issue with VoiceOver and Genius Mixes, issues with converting songs to 128 kbit/s AAC while syncing, addresses a conflict with some third-party software which may cause iTunes for Windows to unexpectedly quit and other issues that improve stability and performance.
Added ability to sync with iPhone 4. Also added ability to sync and read books with iPhone or iPod touch with iOS 4 and iBooks 1.1. Added ability to organize and sync PDF documents as books, and to read PDFs with iBooks 1.1 on iPad and any iPhone or iPod touch with iOS 4. Added option to organize your apps on iOS 4 home screens into folders using iTunes. Speed up back-ups while syncing an iPhone or iPod touch with iOS 4. Album artwork improvements make artwork appear more quickly when exploring your library.
Disables older versions of some incompatible third-party plug-ins. Addresses minor issues with dragging and dropping items. Addresses a performance issue when first syncing to some devices with iTunes 9.2. Addresses an issue upgrading to iOS 4 on an iPhone or iPod touch with encrypted back-ups. Addresses other issues that improve stability and performance. Last version to support Mac OS X Tiger 10.4 on PowerPC G4, G5, and Intel Mac. 
Adds new social networking layer named "Ping". Adds support for iPod shuffle 4G, iPod nano 6G, iPod touch 4G, and Apple TV (late 2010). Renamed AirTunes to AirPlay. Adds visual improvements to list view. Improves performance. Adds additional support for VoiceOver Kit for iPod. Break compatibility with iTunes Server found on many NAS. New application icon.
Adds support for iPad 2, and iOS 4.3. Improves Home Sharing, allowing browsing and playback of entire iTunes libraries on devices running iOS 4.3, and brings back the colored icons in the Preferences window.
Fixes an issue with unresponsive iPad syncing. Fixes an issue with slow syncing of photos on iPhone, iPad, and iPod touch. Fixes an issue with video previews skipping while playing on the iTunes Store. Improves stability and performance.
Adds support for Mac OS X Lion. It now allows users to take advantage of the Full-Screen App capability.GUI slightly improved. Better integration with Windows Vista and Windows 7 (Aero effects support). Many Windows users originally experienced problems with the iCloud purchased music feature on the iTunes Store soon after this update.
Fixes a problem where the media keys on non-Apple keyboards work inconsistently. Addresses issues with adding artwork to songs and videos. Resolves an issue which causes unresponsiveness when purchasing an HD movie. Fixes a problem where iTunes takes longer to open after waking the computer from sleep. Addresses issues with VoiceOver support.
Adds support for iPad (3rd generation). Adds the ability to play 1080p HD movies and TV shows from the iTunes Store. Higher bit rate songs can be converted to 128, 196, or 256 kbit/s when syncing to iOS devices or iPods. Improvements for iTunes Match. Bug fixes.
Fixes possible crash when playing videos, changing artwork size in grid view, or at syncing photos to devices. Addresses issues with VoiceOver and WindowEyes. Fixes problems with iPod nano and iPod shuffle. Resolves an ordering problem with Apple TV.
Addresses an issue where new purchases in iCloud may not appear in one's library if iTunes Match is turned on, makes iTunes more responsive when searching a large library, fixes a problem where the AirPlay button may not appear as expected, and returns the ability to display duplicate items within one's library. It also includes other important stability and performance improvements.
Adds a new Composers view for music, improves responsiveness when syncing playlists with a large number of songs, and fixes an issue where purchases may not show up in your iTunes library. This update also includes other stability and performance improvements.
New feature that lets the MiniPlayer be tweaked to show album art with the player controls hidden and reinstates the MiniPlayer progress bar. Other changes include now showing album art in the songs view, putting multiple disc albums together as one album when in album view, changes to app update management, and improvements in search performance and sorting of large libraries.
Adds the ability to see your Wish List in the iTunes library, improved support for Arabic and Hebrew, and additional stability improvements. The Windows installer now packages iCloud, increasing the installer size by around just under 40MB for the 32-bit and just under 50MB for the 64-bit.