Can I use my iPod on both a Mac and Windows PC?

From the official Apple iPod FAQ:

No, not at the same time. iPod is configured for either Mac or PC. You can use iTunes 7 or later [or the earlier iPod Software Updater utility] to restore iPod to work with a Mac or a PC."

For additional information, please refer to "Restoring iPod to Factory Settings" from the Apple Support Site.

Can I use a Mac-formatted iPod on a Windows PC or vice versa?

Converting a Mac-formatted iPod into a Windows-formatted iPod requires the iPod to be "restored", and doing so will erase the internal storage. Be very certain that any music, photos, videos, or data files are safely backed up before attempting to convert an iPod from one platform to another. Starting with iTunes 7, the software will allow you to use a Windows-formatted iPod on the Mac, but doing so is not supported.

From the official Apple iPod FAQ:

It is not possible to use an iPod formatted for Mac with Windows. This is because Windows does not support the HFS Plus file system and therefore will not see the drive. When you connect an iPod formatted for Mac to your PC, iTunes will prompt you to restore the iPod.

For additional information, please refer to "Restoring iPod to Factory Settings" from the Apple Support Site.

It likewise is worth noting that Apple provides no support for an iPod that has been reformatted for a platform other than the one originally intended.

Can I use the iPod with Mac OS 9?

You can use the original iPod and iPod 2nd Gen with Mac OS 9.2.1. Subsequent iPod models require a Mac running Mac OS X.

Also see: What are the minimum system requirements for each iPod? Will the iPod work with my computer?

Can I use the iPod with Windows 98?

Officially, Apple provides no support for Windows 98. You cannot use the iPod with Windows 98, as the operating system lacks support for FireWire and USB 2.0.

However, with some work, you can use a Windows-compatible iPod with Windows 98. 98-Drivers provides a USB driver that makes it possible to use a number of iPod models -- starting with the iPod (3rd Gen) -- with Windows 98.

As using an iPod with Windows 98 effectively is a "hack", Everyi.com cannot recommend it, but readers have written to confirm that this method works.

Can I use the iPod with Linux?

Officially, Apple provides no support for Linux, and consequently, Everyi.com cannot recommend its use.

However, enthusiasts have released several programs that provide varying degrees of support for the iPod and Linux. Some of these include GNUpod, a series of scripts that provides some level of compatiblity between the iPod and Linux, along with other operating systems that support Perl 5 such as FreeBSD and Solaris 9; GUIPod, based on GNUpod, a Linux program that provides a graphical user interface for managing songs and playlists on an iPod; and GTKPod "a platform independent Graphical User Interface" using GTK2 (no longer online).