iPodLinux is a μClinux-based Linux distribution designed specifically to run on Apple Inc.'s iPod.

When the iPodLinux kernel is booted it takes the place of Apple's iPod operating system and automatically loads Podzilla, an alternative GUI and launcher for a number of additional included programs such as a video player, an image viewer, a command line shell, games, emulators for video game consoles, programming demos, and other experimental or occasionally unfinished software.

Further development of free and open source software for iPods have continued with the Rockbox Project, zeroslackr, and freemyipod, which have largely supplanted iPodLinux.

Apple's proprietary iPod OS in contrast uses an invisible boot loader and is based on an ARM processor kernel originally written by Pixo, and the iPod Miller Columns browser program, a GUI written by Apple and Pixo using the Pixo application framework, and other firmware and component drivers written from manufacturer's reference code to support the standard behavior Apple wanted the iPod to have.

Besides the kernel, iPodLinux features as a primary component podzilla and podzilla2, applications which provide: The bootloader for the 4th generation iPod was extracted by Nils Schneider, a German computer science student.

Schneider was able to use his program with some modifications to make a series of clicks for each byte of the new iPod's bootloader.

A new compression technique called MoviePod, released in 2006, enables people to put more video content on their iPod.