iTunes was based on Soundjam MP, a Mac OS-based audio player made by Casady & Greene in 1999. The software was bought by Apple in 2000 and built upon.
iTunes didn’t have its now central store until V4.0, released in April 2003. The same year Apple included support for Microsoft’s Windows XP and 2000.
Originally iTunes didn’t support playback of many traditional file formats, preferring to convert any inputted file into AAC (advanced audio coding).
One of the most interesting additions to iTunes is Genius. This is an interface integrated playlist creator, which generates a music list based on the user selecting a track.
The latest addition to the iTunes suite is Ping, a social media integration into user interface that allows users to follow artists and share with their friends.