Sharing songs via a network can be done automatically. Shared lists of songs within the same subset are automatically detected, while shared lists outside of the subset can be added by specifing an IP address. The original version of iTunes supported sharing over any network (including the Internet). This was disabled when people started using it in ways that Apple considered to violate their End User License Agreement. Specifically, their concern was targeted at a music-sharing effort called iCommune. (iCommune said and continues to say it did not intend to go afoul of either the contractual agreements, or copyright law.)
On October 16, 2003 Apple released the version of iTunes for the Windows platform. The initial release caused some problems for some users, which were rapidly addressed by the version 4.1.1, released less than a week later.
iTunes is the preferred music player for Mac and Windows PC users using the iPod music player.
The current version for Mac OS X is 4.1. The current version for Windows is 4.1.1. The last version compatible with Mac OS 9 is 3.0, which does not support the Music Store.